E. Hemaprabha

E. Hemaprabha
Indian Institute of Technology Madras | IIT Madras

Doctor of Philosophy

About

20
Publications
6,856
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
169
Citations
Introduction
Skills and Expertise

Publications

Publications (20)
Article
Full-text available
With the rapid commercialization of electric vehicles, fast-charging high-energy batteries are the need of the hour. Developing such high-rate capable batteries need advanced materials beneficial for providing high energy densities and long-lasting cycle life. Silicon, one of the high energy anode materials with a theoretical capacity of 4200 mAh g...
Preprint
Full-text available
The abrupt transition from a disordered phase to collective ion behavior in ferroelectrics serves as a model system to study spontaneous symmetry breaking in nature. First-principle calculations combined with atomic-scale imaging demonstrate that oxygen vacancies that serve as pinning sites for the ferroic domain walls remain immobile above the Cur...
Preprint
Full-text available
Oxygen vacancies in two-dimensional metal-oxide structures garner much attention due to unique conductive, magnetic and even superconductive functionalities they induce. Ferroelectric domain walls have been a prominent recent example because they serve as a hub for topological defects that enable unusual symmetries and are relevant for low-energy s...
Article
Hybrid halide perovskites (HHPs) exhibit exceptional photoelectric properties, facilitating highly efficient modern solar cells and photoconductive technologies. Both ion migration and intrinsic spontaneous polarization have been proposed as the main source of enhanced photoelectric activity, but the exact origin of the advantageous properties has...
Article
We report the controlled fabrication of kinked silicon nanowires (SiNWs) using ethanol mixed facile two-step metal-assisted chemical etching (MACE) method. Accordingly, the kink angle, straight path, and the number of kinks in kinked SiNWs are controlled by varying the volume of ethanol and etching time in high concentrated plating and etching solu...
Article
Full-text available
We report silicon nanoparticles with a particle size distribution of ~ 80 nm (mode) through controlled impact mode cryomilling of semiconductor grade silicon wafers at a temperature of 200 K under argon atmosphere. The transmission microscopic characterization of these particles establishes a partial transformation of the crystalline silicon into a...
Article
The thermoelectric properties of BixSb1-xTe3 processed through milling have been extensively studied with varied results that needs to be rationalized. Since cryo-milling is a relatively cleaner milling process compared to other milling processes, we explore this technique to reduce the particle size prior to compaction to get an insight into the t...
Article
In this work, slanted, kinked and straight silicon nanowires (SiNWs) are fabricated on Si(111) and (100) substrates using a facile two-step metal-assisted chemical etching nanofabrication technique. We systematically investigated the effect of crystallography, morphology of Ag catalyst and composition of etchant on the etch profile of Ag catalyst o...
Preprint
Full-text available
Hybrid-halide perovskite (HHP) films exhibit exceptional photo-electric properties. These materials are utilized for highly efficient solar cells and photoconductive technologies. Both ion migration and polarization have been proposed as the source of enhanced photoelectric activity, but the exact origin of these advantageous device properties has...
Article
We present a green route of synthesis of germanium nanocrystals by cryomilling. The particles (∼ 80 nm) are further functionalized with acrylic acid and dispersed in the isopropyl alcohol (IPA) medium to obtain colloidal ink suitable for inkjet printing under ambient atmosphere to form device grade structure. Printing on silicon wafers presents a c...
Article
Mechanical displacement in commonly used piezoelectric materials is typically restricted to linear or biaxial in nature and to a few percent of the material dimensions. Here, we show that free-standing BaTiO3 membranes exhibit non-conventional electromechanical coupling. Under an external electric field, these superelastic membranes undergo control...
Preprint
Full-text available
Mechanical displacement in commonly used piezoelectric materials is typically restricted to linear or biaxial in nature and to a few percent of the material dimensions. Here, we show that free-standing BaTiO$_3$ membranes exhibit non-conventional electromechanical coupling. Under an external electric field, these superelastic membranes undergo cont...
Article
In ferroelectricity, atomic-scale dipole moments interact collectively to produce strong electro-mechanical coupling and switchable macroscopic polarization. Hence, the functionality of ferroelectrics emerges at a solid-solid phase transformation that is accompanied by a sudden disappearance of an inversion symmetry. Much effort has been put to und...
Preprint
Full-text available
In ferroelectricity, atomic-scale dipole moments interact collectively to produce strong electro-mechanical coupling and switchable macroscopic polarization. Hence, the functionality of ferroelectrics emerges at a solid-solid phase transformation that is accompanied by a sudden disappearance of an inversion symmetry. Much effort has been put to und...
Article
We prepared a two-dimensional layer of silicon nanoparticles at the CuI/TiO2 p-n junction heterophase interface by spray coating of colloidal ink of nanoparticles. The particles are prepared by a physical process of milling at room temperature and further etched to obtain a nanometric size distribution with a mode at ∼2 nm. These particles at the i...
Article
In this work, we have added p-type and n-type Si nanoparticles (NPs) obtained from cryomilling, in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) organic photovoltaic cell at different weight ratios and their effect on organic-inorganic hybrid solar cell device parameters has been evaluated. It is observed tha...
Article
An important aspect that limits the use of carbon nanotubes (CNTs) is the difficulty in obtaining homogeneously dispersed CNTs of uniform length. Hence, homogenization of multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) was carried out using bullet blender and the dispersion behavior was compared with that of ultra...
Conference Paper
Sulfonated polystyrene ethylene butylene polystyrene (SPSEBS) membrane was prepared by evaporation casting method and was used as the Polymer Electrolyte Membrane (PEM) for PEM Fuel Cells (PEMFC). Suitability of the membrane for fuel cell studies was examined. This work analyses the optimization of operating parameters of the fuel cells such as cel...

Questions

Questions (9)
Question
In few areas, it has been written as "nanocrystalline porous silicon" and in other areas, "visible light emission can be obtained from nanocrystalline silicon layers, such as porous silicon (PSi)". So confusion arises about the definition for nanocrystalline silicon and porous silicon
Question
Can I open zirconium powder in open air
Question
I have crystalline Silicon powder with amorphous silicon surface. I want to hydrogenate the surface to reduce the surface defects (you can suggest other ways to avoid the defects). Can you people suggest me the easiest way to hydrogenation?
After doing hydrogenation can I store the powders in hydrazine hydrate solution? Because as far as I know, hydrazine hydrate is a solution form of hydrogen and this solution can act as a non-oxidising element?
Question
The common idea is that storing in N2 glove box. But is there any other method to store silicon thin films.
Question
Yttrium has a high melting point of 1500 deg Celsius while Bismuth's is 270 deg celsius. 
I need suggestions on the method of synthesising this compound.
Question
TiNiSn is a Half-Heusler alloy with VEC = 18.

Network

Cited By