Science topic

Heterostructures - Science topic

Explore the latest questions and answers in Heterostructures, and find Heterostructures experts.
Questions related to Heterostructures
  • asked a question related to Heterostructures
Question
1 answer
I do with heterostructure system like the g- C3N4/TiO2..., any one who know how to make this type of structure by material studio?
Thank you so much for your reply!
Relevant answer
Answer
you may try build structure that option, also you can sketch it. Please check there are some available built-in structures too. Then, you may choose CASTEP for running the simulation.
  • asked a question related to Heterostructures
Question
4 answers
How can we mathematically calculate the critical thickness of polycrystalline(Sputtering) grown thin?
Relevant answer
Answer
Thank you, Dr. Len
  • asked a question related to Heterostructures
Question
2 answers
I am trying to calculate the electronic properties of a vdW heterostructure with the application of the external electric filed. What will be the suitable value for the emaxpos and eopreg in the input file? Using the default values, the bandgap of the monolayers are changing with electric field. Can anybody guide me?
Relevant answer
Answer
How to introduce Electric field effects using VASP, that is, what are the required flags?
  • asked a question related to Heterostructures
Question
6 answers
I found "the correlative plot for monolayer mos2 " in a publication "Spectroscopic evaluation of charge-transfer doping and strain in graphene/MoS2 heterostructures" in (Figure-2b).
However, I can't draw it in origin.
Any idea, how to draw this correlative plot?
Relevant answer
Answer
Thanks😀 to Alexander, Antonis and Rafael for the valuable suggestions 🤝. Now, I plotted the graph.
  • asked a question related to Heterostructures
Question
5 answers
I have been trying to resolve this issue for a long time now trying different strategies and still do not have a fix for this.
The problem:
I have a Si(p++)/SiO2 substrate with a 2D heterostructure consisting of hBN and TMDC. After exposure, I usually develop without a post-exposure baking step. I see cracks appearing only after the development process especially in resist where h-BN is under it. These cracks mostly appear starting from the edges of the pattern and propagate upto 50 microns in distance. I do not see any origin of cracks from the part where the resist is in direct contact with SiO2.
Things I have tried :
1. Different resist materials (PMMA, PMMA with copolymer EL11, ZEP520A). All resist have the same problem.
2. Using rounded corners in my pattern to avoid sharp features. The minimum feature size in my patterns is about 2 µm.
3. Post exposure bake.
4. I am already using low acceleration voltages of 10kV with 30µm aperture.
Can anyone help me with this?
Relevant answer
Answer
We had the same problem on PMMA/MAA/few-layer MoS2, especially the structure which has 1-2 um gaps in between the electrodes. As mentioned above we used cold IPA, and it worked.
  • asked a question related to Heterostructures
Question
1 answer
I want to know how to plot interfacial total charge transfer (=the amounts of transferred
charge) in FET, I attached images below.(pink line in image 2)
It refers to a picture where I want to know how much charge is moved depending on the distance of one axis in the unit cell structure in a heterostructure (2D semiconductor and 3D metal).
I am using VASP code., DFT simulation.
please help me.
Relevant answer
Answer
You may integrate the whole curve of the charge density difference to obtain the total charge transfer amount using the Origin Software. Please refer to the J. Mater. Chem. A, 2018, 6, 8923–8929 and Sustainable Energy Fuels, 2021, 5, 2249–2256, etc.
  • asked a question related to Heterostructures
Question
4 answers
Photodetector is made up of:
cellulose paper as a substrate. Into the substrate we add SnS followed by MoSe 2
Relevant answer
Answer
Nikolay Pavlov Thank you
  • asked a question related to Heterostructures
Question
7 answers
Hello,
I want to model an heterostructure device with the drift-diffusion model, for that I need a boundary conditions. At the heterostructure there is a junction barrier that dictates a thermionic emmition current injection boundary at the junction (J=A*T^2*exp(Phi-dPhi/vt)). Moreover, due to poor surface conditions there is a high surface recombination, which is modeled as Jn=qS(n(0)-np0).
*Phi and dPhi are the junction barrier and reduced junction barrier respectivally.
Does these boundary conditions (thermionic emmition and surface recombination) can be combiend together or they equivalent in some degree?
Not sure how to think about this situation.
Thanks.
Relevant answer
Answer
The following RG link is also very useful:
  • asked a question related to Heterostructures
Question
5 answers
I want to see the effect of transverse electric field on band structure of heterostructure. However I am unable to reproduce the reported results using tefield, dipfield, emaxpos, parameters. Please help me to get the desired results. If possible, please share the input files
Relevant answer
Answer
Hi, I did something related in this article
In short, you must add a saw-like potential to simulate an electric field and dipole correction is also required. For this, in &CONTROL one must add the flags:
tefield = .true.
dipfield = .true.
Next step, I recommend you to set the system at the middle of the periodic unit cell in the z direction. i.e., if c=10A, then your atoms lay down at z ~ 5A.
Finally in &SYSTEM, something like that should be ok:
edir = 3
eamp = ##Amplitude of the electric field, in ***Hartree*** ##
emaxpos = 0.9
eopreg = 0.2
let me know if you need something
  • asked a question related to Heterostructures
Question
4 answers
I want to derive the tight-binding Hamiltonian for a heterostructure. I choose 'random' initial projection and choose the energy window as +(-) 8 eV. I changed the energy window in various ways. Still I am getting "Energy window contains fewer states than number of target WFs". Can anybody help me to resolve the issue? Thanks in advance.
Relevant answer
Answer
No increasing number of iterations is not a good idea, you can just play with the projections you have chosen and the disentanglement windows. That may help!
  • asked a question related to Heterostructures
Question
2 answers
To achieve superlubricity in two-dimensional heterostructures, do we need to stack it at a certain angle? or directly through mechanical exfoliation, we can achieve superlubricity in 2D heterostructures. Please provide some useful suggestions.
I am aware of the concept of commensurate and incommensurate, but in the heterostructure, do we need to follow that?
Relevant answer
Answer
Dear Himanshu Rai ,
Look over the following info:
https://pdf.sciencedirectassets.com/272281/1-s2.0-S1369702119X00061/1-s2.0-S1369702118309039/am.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEJT%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJHMEUCICJd17LNspkDOiMHUUs2OHASAibNTSO92nX9pku6ro4nAiEAhozyHFUD7sc%2F8TclRRlamrtyApI2RxolE0pzk35FGa4qgwQIzf%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FARAEGgwwNTkwMDM1NDY4NjUiDEdQkZd7rij1mHgQuSrXA9SDgP%2FE1jSGk8h%2B7sECHzz8Sd1%2BFqGjuJ6kwk9AEZZ0vjQDmj%2FwWSAZeMwwNlwrNattzQHoU3koF4Uf%2BaSoOXo5LXRpq8u91iGpl9Uru2Z8Q4TNata%2F%2BoG9rXMbofJSK%2BC9cHD15BEgoHAlIVN4XYgkuioasVPUxMBTlQxmxaSvhmChzvaHIOPONA3flTM4Lu7ZJ1bOKGcoidgIRIof1dBYE5IyIUCn0GREJ7loNHmoI4grsgzZEUtHaxPqJ2sUWwEKYCz8DAdInOFwB%2FLb5G%2BIAm%2FfutaF3qX4ENQTgk03334hm64kxC0tm3dWFc9BSWfHrj7tI3dYiFixtAWhkdtovTw8uKEKf0leRASWlaJuiHpfkvQHwNRS8Gw2yd1pSducK%2BF%2FLQjliI0ygcd%2BXzerM8HR%2FugN%2BmjC8lwINs4Y1uev01roCTgFw25hmzDZe45%2FE2fuXyo3jt0yI35vcRjJrmic1ArzkY7XG2e%2FSPQa9tO%2FEPPAZfpsjs6g8gbtoiaHhgd%2FahyBmmpfysirihlF%2BAJ4JnrMZTXlj1P0nznim1RKFWIxmRaZifoQO99S9zfdem7nilbyPkHd7L3cVIfhBNV03WiNT6Ltn4HT7Qsqf4E%2FI12IUTC%2Bo4KQBjqlAVqvI9%2BkpWlG8CG4xCwRrullRh4Ejj2WURsECrqrs0kb16yLmVY%2Fvy8LjYY5UJpcz9K6LeBpTe65S6sBNMknRpHG8y7tCeIRlbybwCwAFn95KKQH3PXaTxetd3Fn1JUcSUXplV9Qbsm%2BTaLHeaiCVkkw%2BzjGLG6MYWjjQCA9MZ6TOhBVyWggE6jUoMIwDEXXkzdkkeFNRG%2F14OLgu61h2SrY3pp3oA%3D%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20220207T050338Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTYRWHCX47F%2F20220207%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=97d6f6e81ab18cd31cb0fef29e65b46152f46a9ee09a035b30f567d31a7e34e4&hash=8af95075615579262700ecd89618ed131f1dc9e3fad9611e719d99f6df54e2e1&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S1369702118309039&tid=pdf-b03dc56e-3086-46bb-914f-0a2f4847ab5e&sid=ee4692f677f0484ec76870f287315b0fdab3gxrqa&type=client
  • asked a question related to Heterostructures
Question
3 answers
I have to fabricate a 2D Hot electron transistor for my project.
I come mainly from a theoretical physics background. So I don't know what to search or read to know about what parameters affect the frequency of a 2D heterostructure Transistor. Can someone help me out by pointing the literature I should really be looking for?
  • asked a question related to Heterostructures
Question
7 answers
A heterostructure is composed by two different materials like pn junction. The work function refers to the potential difference between the interface of a heterostructure.
Relevant answer
Answer
LVHAR = .TRUE. is also fine
  • asked a question related to Heterostructures
Question
2 answers
What substrate should be used and what materials should be used for quantum well etc.
Relevant answer
Answer
depending on calculate the rate
  • asked a question related to Heterostructures
Question
4 answers
I am looking for the deepest quantum well created by semiconductors bands offset in heterostructures. Would greatly appreciate any help!
Relevant answer
Answer
If the combinations are limited within the inorganic semiconductors, it is not very practical to achieve a bandgap shift over 500 meV, due to various limitations, such as lattice mismatch, as mentioned above. However, some organic-inorganic hybrids can achieve much stronger "quantum confinement" effects with a bandgap shift over 1 eV, and more interestingly near perfect crystal structures. See this paper:
  • asked a question related to Heterostructures
Question
3 answers
I looking forward to know how to specify the band gap alignment and band offsets of two layers 2D heterostructure semiconductor?
Can I determine the band alignment (type I or II) without using XPS or STM?
Relevant answer
Answer
I agree with Valentin Bogatu.
  • asked a question related to Heterostructures
Question
5 answers
Hi everyone, I previously asked for your assistance in doing simple calculations using QE, and I would thank you all for your comments.
This time, I want to build a heterostructure of Fe/Sc/Fe using QE, but the problem is I don't know how to prepare the input file for QE. Therefore, my question is how to build the needed input file for QE starting from the Fe.scf.in and Sc.scf.in files. I use Xcrysden for the structure visualisation.
Thank you for your assistance,
Ahmed.
Sc.scf.in file:
&CONTROL
calculation = 'scf' ,
outdir = '/home/ahmed/q-e-qe-6.4.1/tutorials/' ,
pseudo_dir = '/home/ahmed/q-e-qe-6.4.1/pseudo/' ,
prefix = 'Scan_Nitr' ,
/
&SYSTEM
ibrav = 0,
nat = 8,
ntyp = 2,
ecutwfc = 40 ,
ecutrho = 400 ,
occupations = 'smearing' ,
degauss = 0.01 ,
smearing = 'marzari-vanderbilt' ,
starting_magnetization(1) = 0.6,
/
&ELECTRONS
/
CELL_PARAMETERS {angstrom}
4.5112339250 0.0000000000 0.0000000000
0.0000000000 4.5112339250 0.0000000000
0.0000000000 0.0000000000 4.5112339250
ATOMIC_SPECIES
Sc 44.955912 Sc.pbe-spn-rrkjus_psl.1.0.0.UPF
N 14.006700 N.pbe-n-rrkjus_psl.1.0.0.UPF
ATOMIC_POSITIONS {angstrom}
Sc 2.2556169620 2.2556169620 0.0000000000
Sc 0.0000000000 0.0000000000 0.0000000000
Sc 2.2556169620 0.0000000000 2.2556169620
Sc 0.0000000000 2.2556169620 2.2556169620
N 4.5112339240 4.5112339240 2.2556169620
N 2.2556169620 2.2556169620 2.2556169620
N 4.5112339240 2.2556169620 4.5112339240
N 2.2556169620 4.5112339240 4.5112339240
K_POINTS automatic
10 10 10 1 1 1
Fe.scf.in file:
&control
calculation='scf'
pseudo_dir= '/home/ahmed/q-e-qe-6.4.1/pseudo/',
outdir='/home/ahmed/q-e-qe-6.4.1/tutorials/'
verbosity = 'high',
prefix='fe',
/
&system
ibrav = 0,
nat = 2,
ntyp = 1,
ecutwfc = 40 ,
ecutrho = 400 ,
occupations = 'smearing' ,
degauss = 0.01 ,
smearing = 'marzari-vanderbilt' ,
starting_magnetization(1) = 0.6,
/
&electrons
/
CELL_PARAMETERS {angstrom}
2.8443263750 0.0000000000 0.0000000000
0.0000000000 2.8443263750 0.0000000000
0.0000000000 0.0000000000 2.8443263750
ATOMIC_SPECIES
Fe 55.845 Fe.pbe-nd-rrkjus.UPF
ATOMIC_POSITIONS crystal
Fe 0.0000000000 0.0000000000 0.0000000000
Fe 1.4221631880 1.4221631880 1.4221631880
K_POINTS automatic
12 12 12 1 1 1
Relevant answer
Answer
Ahmed Benyahia, you welcome
  • asked a question related to Heterostructures
Question
3 answers
How to figure out the stability of a heterostructure eg. MoSe2-PtS2 heterostructure. How to ensure lattice matching...and how to reduce lattice mismatch if exist.
Relevant answer
Answer
you welcome Vaishali Nimbewal.
  • asked a question related to Heterostructures
Question
3 answers
I want to calculate binding energy of heterostructure crystal via DFT. But I am familiar with CASTEP, not yet have knowledge about any other software. Can I find binding energy of crystal by CASTEP in material studio? If answer is negative , plz suggest me alternative program to do that.
Relevant answer
Answer
Dear M Atikur Rahman in the context of your interesting technical question please have a look at the following potentially useful literature reference which might help you in your analysis:
First principles methods using CASTEP
Fortunately this paper is freely accessible as public full text on RG. Thus you can download it as pdf file. Please also note that a large number of closely related questions have been posted earlier on RG. It might be worth checking the answers given to some of these questions:
I hope this helps. Good luck with your research and best wishes!
  • asked a question related to Heterostructures
Question
3 answers
Au contact on ZnO turned out to be ohmic which has been confirmed by linear response of current in Au/ZnO/Au configuration. But Au/Si/Au is schottky. Now, i have a device with p-Si as the substrate and n-ZnO as the thin film with gold contacts deposited on both Si and ZnO. Given the contact with Si is schottky, will the accuracy of the junction parametrs (ZnO/Si) be compromised?
Can i categorically state that a junction has been formed? or, should i call Au/ZnO/Si/Au as heterostructure device rather than a heterojunction?
Relevant answer
Answer
Dear Abhishek, unfortunately I'm not a specialist in this field enough to give you a qualified expert answer. However, it might be helpful reading the answers given to the following closely related question which has been asked earlier on RG:
What is the difference between heterostructure and superlattice structure?
(19 answers)
Also please have a look at the following potentially useful article which has been published Open Access:
Nanoscale Au-ZnO Heterostructure Developed by Atomic Layer Deposition Towards Amperometric H2O2 Detection
Good luck with your work and best wishes!
  • asked a question related to Heterostructures
Question
2 answers
I did syntheses of pure carbon nitride, pure molybdate and some heterostructures with both. When calculating the bandgap, I noticed that the indirect bandgap of C3N4 is close to what is reported in the literature, but the direct bandgap is not. On the other hand, the molybdate that I used, according to the literature, only has direct bandgap. If so, what choice should I make? To make it easier to understand, I have attached the sketches of the direct and indirect bandgap graphs of the samples.
Relevant answer
Answer
Dear Mario,
In many materials, both direct and indirect interband transitions can exist. The energy gap for indirect transitions is less than for direct transitions, which is quite consistent with the data that you obtained (Eg indirect is about 2.8 eV, Eg direct is about 3.1 eV). In your case, it is quite possible to speak about the existence of two types of interband transitions. Theoretical modeling will help to draw a conclusion about the correctness of the obtained values.
  • asked a question related to Heterostructures
Question
1 answer
I used 'Build Layers' from Build tab. I used it to optimize a heterostructure with GGA - PBE exchange correlation function. Then this error message was shown '*Warning* max. SCF cycles performed but system has not reached the ground state.' .
Later I increased my SCF iterations same happened, then I increased SCF cycle as well as cut-off energy, still this was shown. I did those calculations using 'smart' in 'apply finite basis set correction'.
As those trials were failed so I chose 'never' in 'apply finite basis set correction' and tried all those attempts and still the job was failed and that warning was shown.
What should I do now?
N.B. - I need to study my heterostructure, run electronic and optical calculations. In my heterostructure those two atoms I used were in same phase. Any suggestion in this purpose?
Relevant answer
Answer
Warning: electronic minimisation did not converge during            finite basis set correction.   ******************************************************** Checkpoint file cannot be written. Error calculate_finite_basis : Convergence failed when doing finite basis set correction. Current trace stack: calculate_finite_basis_corr check_elec_ground_state castep Error in calculate_finite_basis:      previous calculation had total energy = -33482.98282286      eV      and this calculation has total energy = -33477.62803476      eV       => something has gone seriously wrong with minimiser Checkpoint file cannot be written. Error in calculate_finite_basis: total energies are not variational - aborting Current trace stack: calculate_finite_basis_corr check_elec_ground_state castep
  • asked a question related to Heterostructures
Question
2 answers
Hello everyone. How can we verify from band diagram, weather the band crossing is pointing towards Dirac metals or weyl metals or it is just normal band crossing.? What observation we should make? What confirmations we need to do ? More generally, just looking at the band structure how could we could say. Please guide me. Thanks.
  • asked a question related to Heterostructures
Question
2 answers
Hello. I want to calculate dispersion curves for vdWH systems. I am trying it using quantum espresso with DFT-D vdw_correction. scf.in, ph.in, q2r.in are running fine, but when i do matdyn.x, calculation just stops without any error or crash. The problem can be seen in the attached picture. Kindly suggest or please guide for a proper calculation of phonon for vdWH system. Eagerly waiting for yours guidance. Thank you.
  • asked a question related to Heterostructures
Question
3 answers
Dear all
What does it mean to have a horizontal line in the negative frequency regime of the phonon dispersion modes? I have a Li ion adsorbed at the surface of a heterostructure. The Li ion is at the saddle point. Actually I want to find the zero point energy of the Li ion. Should I consider the negative frequency of Li? or real? The image is attached.
Thank you for your cooperation.
Abdus Samad
Research associate at the University of Ulsan
Relevant answer
Answer
Hello Abdus Samad , I am getting the same line in my case .
Can you please suggest how to get rid of these negative bands appearing.
I tried to increase the ngrid from 4 4 4 to 8 8 8 but still that doesnt work
  • asked a question related to Heterostructures
Question
2 answers
When ferromagnet (FM) and antiferromagnet (AFM) are coupled, exchange bias can be generated at the interface of FM and AFM which acts as a bias field in the hysteresis loop.
I am particularly interested in the case that FM has perpendicular magnetic anisotropy (PMA) and the localized magnetization in AFM lies in the plane. In this case, it is possible to generate an in-plane bias field to the FM layer.
In a system like PtMn + Co/Ni multilayer, where the Curie (Neel) temperature TC (TN) are both very high ( > 300 C), a typical way to induce this in-plane bias field is by applying a large in-plane field (~ 1T) and annealing the sample at ~300 C, which is below TC. I assume that the annealing is required because it is not a good idea to heat the sample above TC and therefore change the property of the material.
Now, my question is: If I have a similar system (FM with PMA, in-plane AFM), but with room temperature > TC >TN, can I induce an in-plane field by applying a large in-plane filed above TN and then cool the sample to a temperature below TN?
Relevant paper:
Annealing to get bias field:
Neel temperature of AFMs:
Relevant answer
Answer
the is often a confusion between ferrimagnetic effect and ferromagnetic ;when you use YIG like material In the microwave range) its ferrimagnetic !
  • asked a question related to Heterostructures
Question
4 answers
Is it possibile to measure the "back stress" via compressive loading-unloading-reloading (LUR) test? I found numerous publications where back stress is measured using tension LUR test.
Relevant answer
Answer
Steven Van Petegem I want to investigate the evolution of HDI stress in a severely plastically deformed heterogeneous aluminium alloy. Do You think that compression (LUR) test will also be appropriate ?
  • asked a question related to Heterostructures
Question
4 answers
Greetings. I have to etch some regions of a heterostructure to make ohmic contacts. The sample has a Si capping layer which, due to exposure to the atmosphere, is actually a Silicon Oxide layer. Under this Si capping layer, there is a Ge-rich SiGe layer. I have available an 8% HF solution. Is this concentrated enough to etch the Si oxide away? I have seen this done in a few papers but they do not mention the concentration nor mention for how long I should dip the sample.
And one last question if I may: What about the SiGe layer? Will the HF passivate it and prevente native oxide growth? I know HF, HBr, and HCl can be used to clean Ge native oxide and it will prevent the regrowth for about 10min, I am not sure about the SiGe alloy.
Thank you very much.
Relevant answer
Answer
For etching of Si,SiO2 or other materials used in VLSI technology you can use the standard etching solutions given in the link:https://www.microchemicals.com/technical_information/silicon_etching.pdf
In this site you find that only 1 percent diluted HF is suitable for this purpose.
Working with high concentration of HF is more precautious.
Best wishes
  • asked a question related to Heterostructures
Question
1 answer
I have investigated heterostructure for lLIBs; According to my AIMD run, it is thermodynamically stable. Further, I would like to check their thermodynamic stability with formation energy combined with the convex hull method. I need help from the expert, How to get the convex hull energy for my heterostructure?
Looking forward to hearing from the generous scientific community. I will be thankful for your time and considerations.
Your Sincere,
Nisar.
Relevant answer
Answer
Have you been able to obtain the convex hull for the heterostructure?
  • asked a question related to Heterostructures
Question
3 answers
Hi All,
I have a basic doubt related to QDs. Can I realize QDs using any semi-conducting materials, starting from Si, Ge or any other compound S/Cs. If I grow any two layers in the heterostructures, what are the factors based on which I can predict the formation of QDs.
Relevant answer
Answer
Dear Ravindra,
This info below may shed some light:
Who is QDs and what does QDs stand for?
QDS is that partner. All of our technicians and staff are in-house employees that fit the culture of this faith-based, family-owned company. We are willing to sacrifice profitability to ensure excellent customer service.
Quality Data Systems, Inc. - QDS Cash Automation Experts
What kind of disinfectant is Steris process QDs?
STERIS' Process QDS ® Process and Research Cleaner is a phosphate-free, one-step cleaner/disinfectant formulated for use on hard non-porous surfaces. This product is recommended for use in disinfecting, sanitizing, and deodorizing hard non-porous surfaces. It is effective in hard water and organic soil loads.
Process QDS Disinfectant | STERIS Life Sciences
What do you need to know about the qds5 system?
And many more! The QDS5 Assessor Administration module provides the Assessor's Department with a module that addresses all interior administrative needs. This user friendly system has modules for Real Estate, Personal Property, and Motor Vehicle Assessment Administration.
QDS5 | Quality Data - qds.biz
What is Steris process QDs process and research cleaner?
STERIS' Process QDS Process and Research Cleaner is a liquid concentrate specifically formulated for the disinfection of hard non-porous surfaces. The use-dilution can be applied manually or sprayed.
Process QDS Disinfectant | STERIS Life Sciences
  • asked a question related to Heterostructures
Question
1 answer
Dear colleagues:
I need the electrical conductivity or resistivity of the following photocatalytic semiconductors and the following Heterostructures (made of two or more semiconductors joined interfacially). I have had a very hard moments trying to get this kind of information. If you know articles or handbooks that may be useful, please tell me their name so that I can get them.
Semiconductors: TiO2, ZnO, Bi2WO6, BiOI, Ag2O, BiVO4, Bi2O3, SnO2, WO3, MoS2, CuO, Cu2O, MoS2, ZrO2, CdS, α-Fe2O3 , β-PbO2, g-C3N4, GO
Heterostructures: Bi2WO6-rGO, TiO2-Sb2S3, TiO2- MoS2
Best wishes
Marco
Relevant answer
Answer
Dear Marco Antonio Uscanga Olea thank you for this very interesting technical question. I assume that the well-known
CRC Handbook of Chemistry and Physics
could be a valuable source for all this information. It is available online and as printed version in the 101st Edition:
If you find an older edition in the library of your institution this should also be perfectly OK.
Good luck and best wishes!
  • asked a question related to Heterostructures
Question
5 answers
How can I prove the formation of heterojunction between two semiconductors using the XRD spectrum?
Relevant answer
Answer
A physical mixture XRD will certainly show multiple peaks of different orientations for both the compound. Whereas, a clean heterostructure will have lesser number of oriented peaks. Additionally, you may see slight shift in 2 theta position in case of heterostructure due various physical and chemical interactions at the interface such as strain, lattice mismatch, hybridization etc.
you can find a clear difference between a polycrystalline physical mixture XRD (in ESI) and film XRD (Ti3AlC2/c-Al2O3 heterostructure).
  • asked a question related to Heterostructures
Question
1 answer
How does the interface quality of ferromagnet and metal heterostructure (FM/NM) effect the Spin pumping process?
Instead of enhancement in Gilbert damping, is it possible that gilbert damping of this heterostructure (FM/NM) may be reduced????
Relevant answer
Answer
Dear Vinay,
Damping reduction in some FM/NM structures has been reported in many studies to be possible by applying current density on the NM layer while the ferromagnet is under resonance. One condition to observe the reducion is that the NM has a strong spin-orbit coupling or that the two layers produce a Rashba interface. In this case, the damping reduction is promoted by a two-step process. One, the charge current in the non-magnetic metal creates a spin accumulation on the interface via spin Hall effect. And two, the ferromagnet absorbs the spins accumulated on the interface.
An investigation originating in the Indian Institute of Technology and announced in the article claims damping reduction without current induction. The addition of the non-magnetic metallic layer reduces the damping as compared to the bare FM film. This is very uncommon. I think that this is the only published study to date that claims such effect.
  • asked a question related to Heterostructures
Question
2 answers
During the fabrication or hetero-structuring of different TMDs, traps and defects are inherited. These traps contributes/affects on charge transport behavior on various interfaces. To interpret different applications involved TMDs heterostructure, these anomalies and artifacts must be quantified. My specific question is about MoS2/Oxide junction.
Relevant answer
Answer
Thank you Nagesh!
  • asked a question related to Heterostructures
Question
2 answers
Generally i have seen most of the rietveld analysis performed on powder sample. why can we not perform it on thin films and more specifically multilayered heterostructure films?
Relevant answer
Answer
Michael Uebel thank you sir
  • asked a question related to Heterostructures
Question
5 answers
Except the 2D transfer system sold by HQ Graphene
Relevant answer
We published a home-made, extremely cheap machine with heater and vacuum
there are discussions of several opto-electro-mechanical aspects here. This might be helpful.
  • asked a question related to Heterostructures
Question
11 answers
In a p-n heterojunction under internal electric field, the photogenerated electrons and holes will transfer to the n-type semiconductor and the p-type one, respectively. It can be assigned to the fact that CB and VB of n-type semiconductor are normally lower than those of p-type semiconductor. It seems that the type-II heterostructure is similar to this p-n photocatalyst. So what is the main difference between these two heterostructures?
Relevant answer
In the right side p-n junction structure the field region in the transition region will direct the electrons to the n-side where they will be accumulate on the surface of the n-side. At the same time the photognerated holes will be directed to the p-side where they will accumulate on the surface of the p-type material. So, the p-side will be source of holes which is oxidizing. The electrons accumulating on the n-side will be reducing.
The structure in the the right side is composed of two intrinsic materials with the left side has an electron affinity greater than the right side. The two materials have almost an equal energy gap. Both materials are optically active where on absorbing photons they will both generate electron hole pairs.
The electrons will be accumulated on the left side while the holes will be accumulated in the right side.
So, the right side will be oxidizing while the left side will be reducing.
Both will have photovoltaic effect.
The second structure is simpler to produce than the first p-n junction structure.
Best wishes
  • asked a question related to Heterostructures
Question
2 answers
I am trying to calculate the electronic properties of van der Waals heterostructure, calculations goes smoothly for self consistence (scf.in) but for nscf calculations i encountered with en error "Error in routine efermig (1): internal error, cannot bracket Ef". i tried to play with nbnd and cutoff energy and also with mixing beta but every time i got the same error.
I am attaching the nscf.in and nscf.out file herewith, please help me to resolve the issue.
Relevant answer
Answer
Thank you sir for your kind reply....i tried with the technique given in user guide but still getting the same problem....
  • asked a question related to Heterostructures
Question
5 answers
Dear All,
I trying to model heterointerface between two oxides, at first I modeled each surface oxide alone and then I tried to attached OH, O, OOH molecule to find Gibbs free energy. My problem occur when I tried to model the heterointerface. I built my structure using vesta by importing the first unit cell of oxide and enlarge the cell in X and Y direction to fit with the other unit cell of the oxide. I found this procedure is done in some paper to match both lattice parameter. When optimized the oxide alone, the relaxation was not that hard, but when I had an interface between two oxides, the relaxation distort the structure.
I am seeking help in making better structure and relaxation.
This calculation was very costly and I do not want to lose core-hour in the supercomputer.
I appreciate your advice
Relevant answer
Answer
Thank you for sharing the paper; I already finished my work and solve the above problem.
  • asked a question related to Heterostructures
Question
3 answers
Shift in PL emission peaks of SL- WS2 and SL-MoS2 is observed individually under applied strain but due to inter-layer coupling WS2/MoS2 hetero-structure does not show Excitonic behaviour corresponding to both mono-layers rather it shows the PL peaks corresponding to WS2 only in the PL spectra obtained for the hetero-structure. Why?
Relevant answer
Answer
Huo, Nengjie, Zhongming Wei, Xiuqing Meng, Joongoo Kang, Fengmin Wu, Shu-Shen Li, Su-Huai Wei, and Jingbo Li. "Interlayer coupling and optoelectronic properties of ultrathin two-dimensional heterostructures based on graphene, MoS 2 and WS 2." Journal of Materials Chemistry C 3, no. 21 (2015): 5467-5473.
  • asked a question related to Heterostructures
Question
5 answers
While observing overall water splitting of pure water, my heterostructure photocatalyst exhibited H2 evolution initially in 1st hour and then O2 evolution in 2nd and 3rd hour. After that it became inactive. I have used Pt and Ag as cocatalysts.
What can be the possible reason for;
(1). Why it is not able to produce H2 and O2 simultaneously?
(2). Why after 3rd hour, O2 evolution is also stopped?
Relevant answer
Answer
Yes, of course. SEM image can also strictly identify the surface deterioration which meaning that catalyst surface and substrate may be inhibited by it.
You're welcome Muhammad Shuaib Khan.
  • asked a question related to Heterostructures
Question
6 answers
I know we can edit the layers (and make different cifs) and do the calculation for each layer separately to find their HOMO-LUMO. But I was wondering if there's a way to calculate HOMO-LUMO of each layer, while the layers are stacked in the heterostructure in a single cif. Thanks!
*I'm using Quantum Espresso. But I guess the problem is same the regardless of the code one is using.
Relevant answer
Answer
Atom projected (site projected) DOS calculations almost always produce output for sites indexed based on the order you defined your coordinates in the input file.
So, if you know which atom is which in your input, it should be no problem working out which ofns to sum.
If your heterostructure is large, it may be convenient to use the ASE interface for QE to work out which atom indexes belong to which layer.
I hope this helps.
  • asked a question related to Heterostructures
Question
1 answer
We have obtained extensive XRD, TEM and other relevant data about the crystal heterostructure (it is a metal core-shell quantum dot). What is the formula for determining the lattice mismatch between the two materials (core-shell)?
Thank You!
Relevant answer
Answer
Hi,
Lattice Mismatch between core and shell can be calculated by using XRD patterns planes of core and shell structures by formula
% Lattice Mismatch = 100 × [ 𝑑(core) − 𝑑(shell)]/ 𝑑(core)
Note: Use the same diffraction plans of core and shell
  • asked a question related to Heterostructures
Question
7 answers
2D hetero-structures are finding numerous applications in energy storage, flexible electronics and nano-composites. But there has not been much experimental work in investigating the mechanical properties (elastic modulus, shear modulus, inter-layer friction etc.). Let us discuss what has been done in this field. Just to trying to keep ourself busy with some fundamental scientific discussions while we are locked down in our homes.
#graphene #2DMaterials #hBN #Heterostructures
Relevant answer
Hi, a heterojunction is an interface that occurs between two layers or regions of dissimilar semiconductors. There are two known methods for its preparation: Top-down: Micromechanical Exfoliation. Simple as it seems, this technique is able to yield high-quality 2D crystal flakes, applied to many common-used 2D materials, such as graphene, MoS2, WSe2 . Bottom-up: Chemical vapor deposition (CVD). This method is mainly used to prepare larger films with more stable quality. One of the most popular application is to adopt it for growing MoS2 uses S and MoO3 as precursors. And used in cases such as Lasers, bipolar transistors, solar cells and field-effect transistors.(https://en.wikipedia.org/wiki/Heterojunction) And I suggest this book too: https://b-ok.cc/book/599935/386d87
  • asked a question related to Heterostructures
Question
5 answers
What are the most useful mechanical applications of two dimensional heterostructures? And what are the most efficient 2D heterostructure systems for flexible electronics?
Relevant answer
Answer
Dear Dr. Md Tawabur Rahman , Dr. Farrokhfar Valizadeh Harzand and Maharshi Dey .....thank you so much for your kind suggestions. I have started looking into the resources.
Maharshi Dey , since MXenes are mostly liquid processed, it is incredibly difficult to have pristive bilayer/hetero-structure of MXenes. That's the reason we focused more on traiditional 2D materials which have established transfer protocols. MXenes are incredible materials and we really want to look into their mechanical properties. If you have any suggestion regarding the problem I state above, please let me know.
  • asked a question related to Heterostructures
Question
3 answers
up to critical thickness
Relevant answer
Answer
Dear Pawan,
welcome,
Would you please add details to your question to make it clear. Which barrier you mean? Is it the barrier of the two dimensional gas at the surface of GaN layer, or the barrier caused by the AlGaN?
Here i will assume that it is the barrier of the two sedimentation gas.
As the potential barrier of this two dimensional gas increases, the scattering at its wall decreases and thereby the mobility increases. This is because the electrons will flow mostly in the middle of the potential well.
Best wishes
  • asked a question related to Heterostructures
Question
8 answers
How to construct a heterostructure in Quantum Espresso for e.g: GaAs/GaN?
Relevant answer
Answer
Dear Saurav,
It will be easier if you construct each of the GaAs and GaN monolayers individually. Then, concatenate them together with considering a distance between two monolayers by adding a constant value to the coordinates of the second monolayer.
On the website Materials Project, you can find the CIF file for both intended monolayers. Also, it provides open web-based access to many crystal structures of materials.
  • asked a question related to Heterostructures
Question
1 answer
I am working on development of Z-scheme based heterostructure photocatalyst in which both semiconductor components are structurally engineered (doped and defected). What parameters should be considered for successful direct Z-scheme design.
Relevant answer
Answer
Photoluminescence Spectroscopy analysis is used to evaluate the recombination rate of photoinduced electron and hole pairs. I think this technique is usefusefulule.
  • asked a question related to Heterostructures
Question
2 answers
Dear Siesta Users,
I work on a 2D lateral heterostructure with siesta 4.0.2.
I have used the super-cell approach with a vaccume region of 20 Å perpendicularly to the sheet.
I have checked my code by lateral and vertical graphene heterostructures and they were okay and the vacuum region didn't have altered much. But In my structure vacuum region get extremely bigger also I checked my code by using GGA-PBE, GGA-revPBE and LDA-CA. any help would be appreciated.
Relevant answer
Answer
Dear Aadhityan Arivazhagan
Thanks for your reply.
  • asked a question related to Heterostructures
Question
8 answers
I want to make a Teflon reactor , with quartz window for Photo-electrochemical characterization having three electrodes . I need help in making can some show me the photo or the sketch how to make it .
TO KNOW MORE ABOUT MY QUERY read the " section 2.3 " as ------
The PEC experiments were performed in a Teflon reactor equipped with a quartz window for frontal illumination. All the tests were carried out in a three electrode configuration using the TiO2 NP film, TiO2 NTs, ZnO NWs or ZnO@TiO2 core– shell heterostructures as the working electrodes for the water photo-electrolysis reaction, a platinum wire as the counter electrode, and an Ag/AgCl (KCl 3 M) as the reference electrode, in a 0.1 M NaOH aqueous electrolyte (pH = 12.7).
here i got no idea what the reactor is . and i need to make it .. help me in making it .
  • asked a question related to Heterostructures
Question
1 answer
Electron affinity values reported in literature are mostly of monolayer or bulk TMDC materials. However, is there any reported data/method/ way to calculate affinity of bilyer TMDC materials and their heterostructures(i.e. MoS2/WS2)? 
Thanks in advance.
Relevant answer
Answer
Hello
You may refer to the following attachement, some materials data were refer-in.
Thanks
  • asked a question related to Heterostructures
Question
5 answers
Dear community. As far as I understand, the dielectric confinement problem is scale invariant, while the quantum confinement problem has a length scale defined by the Bohr radius.
I have been trying to understand some experimental results in terms of the change in dielectric confinement of the system: one material phase, with a higher permittivity, embedded into a secondary phase with a lower permittivity. After some treatment, the phases distribution change, with the first phase increasing its volume ratio. This will be consistent with changes in dielectric confinement. The problem is that the scale of the phases is way above the Bohr radius of the specific material, and all the literature I have found, deals with dielectric confinement only for very confined systems, within the quantum confined scale.
Can anyone point me to some literature that deals with the scale of dielectric confinement?
Thanks.
Relevant answer
Answer
The dielectric confinement is exploited in the dielectric waveguides such as the glass fiber. The confinement is based on the total reflection at the boundary of the two materials. It requires a boundary with two different dielectric constant and a an incident angle greater than that required for the total reflection. So the confinement may occur in a fiber with a dimensions in the order of the ligfht wavelength.
Best wishes
  • asked a question related to Heterostructures
Question
5 answers
Recently, i am using VASP to optimize a heteroscurture by setting isif = 3 or 4,but the result of the optimization shows that the lattice constant of the heterostructure is bigger that the two materials` .
I tried to use a 2x2 supercell , but i got the same result in ferromagnetic settings.Anti-ferrimagnetic settings comes lattice constant between two materials.
The total energy is lower in ferromagnetic settings.
One of the materials is ferromagnetic and the other one is non-magnetic.
Will it happen in a vdW 2D heterostructure?
Relevant answer
Answer
Firstly, if your lattice mismatch is 0.6%, it is excellent.
Secondly, the lattice constants are mentioned in Table I for the different stacking. The lattice constants of these heterostructures as follows 3.31, 3.33, and 3.32 Angstrom for AA, AB, and BB stacking orders, respectively. in addition, it can be obtained these lattice constants from CONTCAR after the relaxation.
Thirdly, we can obtain the optical anisotropy from the values of refractive index (n), where any material become isotropic due to stabilizing the values of n (the change in n approach to zero) otherwise the material is anisotropic where Δn> 0.
But there is a better method to find the optical anisotropy in materials by finding the difference between the horizontal and vertical refractive indices, the latter method exists in the attached papers in details.
  • asked a question related to Heterostructures
Question
8 answers
Responsivity is a measure of the electrical output per optical input.
Relevant answer
Answer
We need more information for above question
  • asked a question related to Heterostructures
Question
1 answer
We have recently synthesized a colloidal solution of (what we think is) 2D heterostructure. We first prepared a colloidal solution of an exfoliated 2D material and synthesized a different quasi-2D material in that solution. We have shown that the second material is indeed synthesized. We have a strong hunch that the latter material is being synthesized on top of the exfoliated 2D material, but this is hard to verify. What is the best way of checking if the two materials are existing separately, forming heterostructure, or both?
Relevant answer
  • asked a question related to Heterostructures
Question
3 answers
I need to know about the material to use as a medium or spacer between GaAlAs/GaAlAs layers and for GaAlAs/GaAs heterostructure. How would I make the selection of the spacer material for these type of bilayer system? If any other suggestion you need to give then please tell me.
Relevant answer
Answer
Dear Sharad,
welcome,
What is the function of the spacer layer in the intended structure and how is the layer stack required? The choice of the material depends on its fucntion in the structure. Do you want to make multijunction tandem solar cell from three five compounds?
Best wishes
  • asked a question related to Heterostructures
Question
1 answer
Dear all,
I am wondering if we have to capsulate any tunneling device based on vdW heterostructure by h-BN in top and bottom as well? to let current pass through overlapping area of three layers stacked vertically ????
many thanks
Relevant answer
Answer
Following
  • asked a question related to Heterostructures
Question
4 answers
Most of the people build their own transfer stations to move flakes of 2D materials (e.g. graphene), but I'm interested in knowing if there is any company selling a complete transfer station including software to do the transfer.
Relevant answer
HQ Graphene offers complete system: http://www.hqgraphene.com/TransferSystem.php
  • asked a question related to Heterostructures
Question
2 answers
Dear community,
I'm looking for Post-Doc position in :
-Metal nano-oxide synthesis ( eco-design and application in environment): examples: ZnO, TiO2.....
and/or
Nano-composites ( noble metal/ metal oxide for energy and health applications): examples: Ag/ZnO, Au/ZnO......
and/or
Reduced metallic nano particles for antibacterial activities
Thank you 
Relevant answer
Answer
Wishing you all the best with your search.
I would also suggest searching onthe following websites:
  • asked a question related to Heterostructures
Question
4 answers
I have a coherent THz acoustic phonon parametric oscillator, via a doping superlattice grown by MBE on (100) silicon, and now wish to transmit the generated phonons into a single-crystal antiferromagnet, grown epitaxially on the (100) Si substrate (perhaps using a buffer layer), for magnon-phonon studies. I am searching for a paper describing such a heterostructure. Would appreciate a reply with a paper describing such a fabricated heterostructure. I could alternatively possibly use GaN as the substrate, provided it can be modulation-doped. Thank you.
Thomas Wilson
Relevant answer
Answer
Dear Dr. Wilson,
I have no experimental experience with this problem. I found by Google search a hit for the antiferromagnet MnF2:
Epitaxial growth on silicon and characterization of MnF2 and ZnF2 layers with metastable orthorhombic structure
Journal of Applied Physics 98, 013519 (2005); https://doi.org/10.1063/1.1944909
  • asked a question related to Heterostructures
Question
2 answers
how can we calculate the work function of 0-D (quantum dot or nanocrystal or molecules) and 3-D (bulk) materials using density functional theory?
Relevant answer
Answer
Dear Askari,
The following article will answer your question:
Langreth, D.C., Dion, M., Rydberg, H., Schröder, E., Hyldgaard, P. and Lundqvist, B.I., 2005. Van der Waals density functional theory with applications. International journal of quantum chemistry, 101(5), pp.599-610.
  • asked a question related to Heterostructures
Question
6 answers
I know that Rashba coupling parameter magnitude in experiments is about 0.1 eV.A. I also have seen some papers that has reported gigantic Rashba couplings about 0.3 eV.A or higher magnitudes. If fact, I need to know that can we have small quantum rings (radius 20-60 nm) with about 0.2 eV.A or higher Rashba coupling?
Relevant answer
Answer
P. Contreras you are welcome Prof. Contreras.
  • asked a question related to Heterostructures
Question
5 answers
Thin film deposition of same materials (Polyaniline emeraldine salt and base) one is conducting and another is non conducting. Thin film being deposited and termed as heterostructure, is it correct?, junction of layered thin films.
Relevant answer
Answer
Traditionally, a heterojunction is referred to an interface of two different materials in chemical content. However, it has been extended to other situations such as an interface of the same material but different structures (e.g., ZB GaAs and WZ GaAs), of the same material but different crystal orientations (e.g., a structure known as orientational superlattice), etc.
  • asked a question related to Heterostructures
Question
1 answer
I am trying to make Hall bars on InAs/AlGaSb based heterostructure . For that I am doing optical lithography to cover the area which I want to protect with a positive resist(S1813 or S1828). After that I etched the sample with solution of 1 molar citric acid (C6H8O7), 85% phosphoric acid (H3PO4), and 30% hydrogen peroxide (H2O2) with volume ration of 97.17%: 1.06%: 1.77% . But from the optical image and AFM image, it is clear that etching is not happening that smooth and the roughness of the etched area is pretty high. I am still trying to figure out the problem.
Any suggestion regarding the potential reason and solution will be highly appreciated. Thanks in advance.
Relevant answer
Answer
This articles may help you
  • M. N. Kutty, etal "Study of Surface Treatments on InAs/GaSb Superlattice LWIR Detectors", Journal of Electronic Materials 39(10):(2010), 2203-2209
DOI: 10.1007/s11664-010-1242-0
  • K.C. Goma Kumari, H.M. Rawool, and S. Chakrabarti, “Demonstration of Fabricated Midwave Infrared InAs/GaSb Type-II Superlattice-based Focal Plane Arrays”, Defence Science Journal, Vol. 67, No. 2, March 2017, pp. 149-153,
DOI : 10.14429/dsj.67.11178,
I hope these papers will help
  • asked a question related to Heterostructures
Question
5 answers
Could anyone please help, i m working on tertiary composite as photo catalyst for Hydrogen production, which characterization method i should use to know the internal connection of component with each other that how they make heterostructure or through which bonds they make composites??? a deeply molecular level not the most common one like FTIR,XRD,SEM, elemental mapping etc if possible then plz consider my request thank you.
Relevant answer
Answer
TEM can help if you get the high resolution images. Best of luck!
  • asked a question related to Heterostructures
Question
9 answers
In 3D code like plane wave, we need to make supercell and large vacum to study the properties, if we have 2D code, we should not need to make supercell and computational cost also will be low.
Relevant answer
Answer
The CRYSTAL code (http://www.crystal.unito.it) can work with 2D periodic boundary conditions.
  • asked a question related to Heterostructures
Question
3 answers
The real part and imaginary part of refractive index of a bulky material comply with the Kramers-Kronig relation, does the same apply for the effective refractive index and the modal gain in an active waveguid structure (e.g, a double heterostructure semiconductor laser)?
Relevant answer
Answer
The Kramers-Kronig relations are not always valid for the effective index of a mode in waveguides. For example, the fundamental mode of a lossless dielectric waveguide (e.g., a single mode fiber) will have a dispersive effective index, but no loss. Thus the effective index cannot satisfy the Kramers-Kronig relation. It turns out that it satisfies a generalized form of the KK relations in which the mode dispersion is connected to the imaginary parts of the evanescent modes (see ).
  • asked a question related to Heterostructures
Question
4 answers
Since quantum well lasers are made up with heterostructures is there any chance of a photon to be emitted with a different energy of the one related to the well bandgap? I mean the energy of the bandgap of the semiconductor without the well.
Relevant answer
In a quantum well laser, states are quantized in the conduction and valence bands. Therefore, the transition energy will be greater than the bandgap of the material.
  • asked a question related to Heterostructures
Question
8 answers
Ag nano particles are deposited by electron beam evaporation method on mechanically exfoliated MoS2. And XPS data were taken freshly after Ag deposition and after long exposure to ambient atmosphere.
Relevant answer
Answer
You have to compare the metal sulfide and metal disulfide bond. As you know sulfur has variable oxidation states depending upon the nature of oxidation state the pattern may change. You please refer some papers on high light sulfur on silver and gold surfaces. area of the peak splitting also give you some information.
  • asked a question related to Heterostructures
Question
4 answers
I have synthesized quantum dot/nanowire heterostructure catalyst. I observed the reductive photocurrent of my catalyst reduced by x4 when doing it in O2 free environment compared to ambient condition. What would be the reason for that reduction of photocurrent in O2 free conditions.
Relevant answer
Answer
The experiment must be carried out under inert gas. What you see is the reduction of O2.
Dear Abdullah, You may post the same answer to all questions in RG forum. This would help to increase your RG score. I recommend your answer (which I consider as a spam) to help you to increase your RG score.
  • asked a question related to Heterostructures
Question
9 answers
I want to know more about the difference between heterostructure composite. How is homostructure composite different from it, only in terms of band gap? Is there any difference between homostructures and composites or is it the same?
Relevant answer
Answer
Hi Sukriti,
Heterostructures are the materials made up of different metals or components. They are not separate species. You will get only one morphology where they are completely blended with each other. They are interlinked. Ex. MnMoO4, CuWO4
Composites are the materials where 2 or more components present independently with given ratio. They will have individual identity and can be observed through SEM and TEM. Ex. Cu2S-MoO3.
In terms of band gap, for heterostructures usually get only one band gap energy (sometimes 2) but composites get minimum of 2 band gap energies.
Core-shell structures are those where one component is enveloped by other. These may be considered as a type of composites. Of coarse band gap energy will not be same as that of either of the components. It depends on the composition ratio.
Hope it helps
  • asked a question related to Heterostructures
Question
2 answers
Lot of people have done investigations on 'valance band offset' of heterostructures while 'conduction band offset' studies are rarely found. Is it experimental difficulties or Irrelavancy of information?
Relevant answer
Answer
.
both VB and CB offsets are important to understand the properties of heterostructures
you might have the impression that the focus is mainly on the VB because of the experimental technique to probe the band alignment in heterostructures
first the VB alignment is determined using XPS for instance
usually band gaps are already known (from spectoscopic techniques for instance)
and finally the CB offset follows
.
  • asked a question related to Heterostructures
Question
3 answers
We know that one-dimensional (1D) or two-dimensional (2D) materials have confined space for charge, or electron transportation, which makes them promising in conductive or semi-conductive devices. Obviously we cannot say which one is better. Can anyone explain the difference between 1D and 2D in terms of their specific applications?
Relevant answer
Answer
For some applications 1D is advantageous and some other cases 2D is better. It depends on case-by-case. But if you want to compare 1D & 2D effects side-by-side in any particular case, you can certainly do that. In that case you should choose similar material composition for 1D & 2D materials and compare them in similar application. Here is one of my previous review paper where I was exactly trying to do that. This was the comparison between Carbon 1D material (CNT) and Carbon 2D material (Graphene) in electronic and optoelectronic applications. If you are interested you can check that out..
  • asked a question related to Heterostructures
Question
3 answers
Dear All,
I want to build a hetero-structure based on 2D materials or mixed-dimensional materials such as a 2D/3D assembly?
I am wondering what is the following procedure I should do it to make it for keeping the physical properties of electronic devices, or during studying optoelectronic properties are similar or close to each other??
I have prepared 2D materials using a scotch tape (exfoliation technique) and I utilize a dry transfer for making a vertical stacking?
do you think contaminants resulting from adhesion tapes or non-flatten surfaces play a main role? how should be overcome ? are there other factors should be taken in account?
thanks in advance
Relevant answer
Answer
Dear Ali, thanks for answering . do you have any files explaining that in hetero-structure based on 2D materials