G J Salamo

Publications (198)498.66 Total impact

• Article: Electron Transport in Quantum Dot Chains: Dimensionality Effects and Hopping Conductance

  Vas. P. Kunets, ∗ M. Rebello Sousa Dias, T. Rembert, M. E. Ware, Yu. I. Mazur, V. Lopez-Richard, † H. A. Mantooth, G. E. Marques, G. J. Salamo
  Journal of Applied Physics 05/2013; · 2.17 Impact Factor
• Article: Effect of resonant tunneling on exciton dynamics in coupled dot-well nanostructures

  D. Guzun, Yu. I. Mazur, V. G. Dorogan, M. E. Ware, E. Marega Jr, G. G. Tarasov, C. Lienau, G. J. Salamo
  Journal of Applied Physics 04/2013; 113:154304. · 2.17 Impact Factor
• Article: Strong excitation intensity dependence of the photoluminescence line shape in GaAs1-xBix single quantum well samples

  Yu. I. Mazur, V. G. Dorogan, M. Schmidbauer, G. G. Tarasov, S. R. Johnson, X. Lu, M. E. Ware, S. Q. Yu, T. Tiedje, G. J. Salamo
  Journal of Applied Physics 04/2013; 113:144308. · 2.17 Impact Factor
• Article: Site-controlled formation of InGaAs quantum nanostructures — Tailoring the dimensionality and the quantum confinement

  B. Liang, P. S. Wong, T. Tran, V. G. Dorogan, Yu. I. Mazur, M. E. Ware, G. J. Salamo, C. K. Shih, D. L. Huffaker
  Nano Research 04/2013; 6(4):235. · 6.97 Impact Factor
• Article: MBE grown GaAsBi/GaAs double quantum well separate confinement heterostructures

  D. Fan, P. C. Grant, S. Q. Yu, V. G. Dorogan, X. Hu, Z. Zeng, C. Li, M. E. Hawkridge, M. Benamara, Yu. I. Mazur, G. J. Salamo, S. R. Johnson, Zh. M. Wang
  Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures. 02/2013; 31(3):03C105.
• Article: Strong passivation effects on the properties of an InAs surface quantum dot hybrid structure.

  A Lin, B L Liang, V G Dorogan, Yu I Mazur, G G Tarasov, G J Salamo, D L Huffaker
  [show abstract] [hide abstract]
  ABSTRACT: We report on an InAs quantum dot (QD) hybrid structure with a top surface QD layer coupled to two buried QD layers that is highly sensitive to surface passivation. After 180 min of passivation, the photoluminescence (PL) peak of the surface QDs shifts from 1545 to 1275 nm while its intensity decreases by one order of magnitude. Time-resolved PL reveals a significant decrease of carrier tunneling between the QD layers because of the surface state modification by chemical treatment. A simple model with rate equations is used to explain the observed optical performance. Our results show that the optical performance of this hybrid structure is very sensitive to the surface environment, making it a potential candidate for sensing applications.
  Nanotechnology 01/2013; 24(7):075701. · 3.98 Impact Factor
• Article: Effects of spatial confinement and layer disorder in photoluminescence of GaAsBi/GaAs heterostructures

  Yu.I. Mazur, V.G. Dorogan, M. Benamara, M.E. Ware, M. Schmidbauer, S.R. Johnson, X. Lu, S.Q. Yu, T. Tiedje, G.J. Salamo
  Journal of Physics D: Applied Physics. 01/2013; 46:065306.
• Article: Effect of tunneling transfer on thermal redistribution of carriers in hybrid dot-well nanostructures

  Yu.I. Mazur, V.G. Dorogan, E. Marega Jr, D. Guzun, M.E. Ware, Z.Ya. Zhuchenko, G.G. Tarasov, C. Lienau, G.J. Salamo
  Journal of Applied Physics 01/2013; 113:034309. · 2.17 Impact Factor
• Article: In-plane mapping of buried InGaAs quantum rings and hybridization effects on the electronic structure

  M. D. Teodoro, A. Malachias, V. lopes-Oliveira, D. F. Cesar, V. Lopez-Richard, G. E. Marques, E. Marega Jr, M. Benamara, Yu. I. Mazur, G. J. Salamo
  [show abstract] [hide abstract]
  ABSTRACT: This work reports the investigation on the structural differences between InAs quantum rings and their precursor quantum dots species as well as on the presence of piezoelectric fields and asymmetries in these nanostructures. The experimental results show significant reduction in the ring dimensions when the sizes of capped and uncapped ring and dot samples are compared. The iso-lattice parameter mapped by grazing-incidence x-ray diffraction has revealed the lateral extent of strained regions in the buried rings. A comparison between strain and composition of dot and ring structures allows inferring on how the ring formation and its final configuration may affect optical response parameters. Based on the experimental observations, a discussion has been introduced on the effective potential profile to emulate theoretically the ring-shape confinement. The effects of confinement and strain field modulation on electron and hole band structures are simulated by a multiband k.p calculation.
  Journal of Applied Physics 07/2012; 112(1):014319. · 2.17 Impact Factor
• Source

  Available from: Vasyl Peter Kladko

  Article: Substrate effects on the strain relaxation in GaN/AlN short-period superlattices.

  V P Kladko, A V Kuchuk, P M Lytvyn, O M Yefanov, N V Safriuk, A E Belyaev, Yu I Mazur, E A Decuir, M E Ware, G J Salamo
  [show abstract] [hide abstract]
  ABSTRACT: We present a comparative study of the strain relaxation of GaN/AlN short-period superlattices (SLs) grown on two different III-nitride substrates introducing different amounts of compensating strain into the films. We grow by plasma-assisted molecular beam epitaxy (0001)-oriented SLs on a GaN buffer deposited on GaN(thick)-on-sapphire template and on AlN(thin)-on-sapphire template. The ex-situ analysis of strain, crack formation, dislocation density, and microstructure of the SL layers has established that the mechanism of strain relaxation in these structures depends on the residual strain in substrate and is determined mainly by the lattice mismatch between layers. For growth on the AlN film, the compensating strain introduced by this film on the layer prevented cracking; however, the densities of surface pits and dislocations were increased as compared with growth on the GaN template. Three-dimensional growth of the GaN cap layer in samples with pseudomorphly grown SLs on the AlN template is observed. At the same time, two-dimensional step-flow growth of the cap layer was observed for structures with non-pseudomorphly grown SLs on the GaN template with a significant density of large cracks appearing on the surface. The growth mode of the GaN cap layer is predefined by relaxation degree of top SL layers.
  Nanoscale Research Letters 06/2012; 7(1):289. · 2.73 Impact Factor
• Article: Comparison of MBE Growth of InSb on Si (001) and GaAs (001)

  T. Lien Tran, Fariba Hatami, W. Ted Masselink, Vas P. Kunets, G.J. Salamo
  [show abstract] [hide abstract]
  ABSTRACT: We describe the epitaxial growth of InSb films on both Si (001) and GaAs (100) substrates using molecular-beam epitaxy and discuss the structural and electrical properties of the resulting films. The complete 2μm InSb films on GaAs (001) were grown at temperatures between 340°C and 420°C and with an Sb/In flux ratio of approximately 5 and a growth rate of 0.2nm/s. The films were characterized in terms of background electron concentration, mobility, and x-ray rocking curve width. Our best results were for a growth temperature of 350°C, resulting in room-temperature mobility of 41,000cm2/Vs. For the growth of InSb on Si, vicinal Si(001) substrates offcut by 4° toward (110) were used. We investigated growth temperatures between 340°C and 430°C for growth on Si(001). In contrast to growth on GaAs, the best results were achieved at the high end of the range of T S =  C, resulting in a mobility of 26,100cm2/Vs for a 2μm film. We also studied the growth and properties of InSb:Mn films on GaAs with Mn content below 1%. Our results showed the presence of ferromagnetic ordering in the samples, opening a new direction in the diluted magnetic semiconductors.
  Journal of Electronic Materials 04/2012; 37(12):1799-1805. · 1.47 Impact Factor
• Article: Photoconductivity peculiarities in InGaAs quantum wire heterostructures: anisotropy and high photoresponsivity at room temperature

  S V Kondratenko, O V Vakulenko, Vas P Kunets, Yu I Mazur, V G Dorogan, M E Ware, G J Salamo
  Semiconductor Science and Technology. 01/2012; 27.
• Article: Effect of dimensionality and morphology on polarized photoluminescence in quantum dot-chain structures

  Y I Mazur, V G Dorogan, M E Ware, E Marega, P M Lytvyn, Z Y Zhuchenko, G G Tarasov, G J Salamo
  [show abstract] [hide abstract]
  ABSTRACT: Change of the photoluminescence (PL) polarization is studied by changing the excitation intensity and temperature for aligned In(Ga)As quantum dot (QD) structures with varying inter-dot distances grown by molecular beam epitaxy on semi-insulating GaAs (100) substrates. An unusual increase of the polarization ratio is observed by increasing the temperature and/or excitation intensity throughout a low temperature (T < 70K) and low intensity (I-ex < 1 W/cm(2)) range. This increase as well as the general behavior of the polarized PL are the results of the exciton dynamics and the peculiarities of the system morphology. They are due to the varying inter-dot distances which change the system from zero-dimensional comprised of isolated QDs to one-dimensional comprised of wire-like structures. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4759318]
  Journal of Applied Physics. 01/2012; 112(8).
• Article: Polarization doping: Reservoir effects of the substrate in AlGaN graded layers

  S B Li, M E Ware, J Wu, V P Kunets, M Hawkridge, P Minor, Z M Wang, Z M Wu, Y D Jiang, G J Salamo
  [show abstract] [hide abstract]
  ABSTRACT: High electron sheet concentrations of similar to 10(15) cm(-2) result from polarization doping with compositionally graded AlGaN films grown on unintentionally doped GaN templates which exhibit background electron concentrations of similar to 10(16) cm(-3). Similar graded films grown on semi-insulating (SI), free standing GaN substrates exhibited carrier concentrations two orders less. Transport studies of the as-grown materials using temperature dependent Hall effect revealed a very weak temperature dependence of the carrier concentration and mobility as compared to traditionally doped films using Si as a dopant. And qualitative modeling of the electron mobility indicates that alloy scattering and charged dislocation scattering are the most significant contributors to limiting the mobility over the entire temperature range. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4750039]
  Journal of Applied Physics. 01/2012; 112(5).
• Article: InGaAs quantum wire intermediate band solar cell

  Vas P Kunets, C S Furrow, T Al Morgan, Y Hirono, M E Ware, V G Dorogan, Yu I Mazur, V P Kunets, G J Salamo
  Applied Physics Letters 01/2012; 101:041106. · 3.84 Impact Factor
• Article: Molecular beam epitaxy growth of GaAsBi/GaAs/AlGaAs separate confinement heterostructures

  D. Fan, Z. Zeng, X. Hu, V. G. Dorogan, C. Li, M. Benamara, M. E. Hawkridge, Yu. I. Mazur, S.-Q. Yu, S. R. Johnson, Zh. M. Wang, G. J. Salamo
  Applied Physics Letters 01/2012; 101:181103. · 3.84 Impact Factor
• Article: Coexistence of type-I and type-II band alignments in antimony-incorporated InAsSb quantum dot nanostructures

  Yu. I. Mazur, V. G. Dorogan, G. J. Salamo, G. G. Tarasov, B. L. Liang, C. J. Reyner, K. Nunna, D. L. Huffaker
  Applied Physics Letters 01/2012; 100:033102. · 3.84 Impact Factor
• Article: Strain-free ring-shaped nanostructures by droplet epitaxy for photovoltaic application

  J. Wu, Zh. M. Wang, V. G. Dorogan, S. Li, Zh. Zhou, H. Li, J. Lee, E. S. Kim, Yu. I. Mazur, G. J. Salamo
  Applied Physics Letters 01/2012; 101:043904. · 3.84 Impact Factor
• Article: Bismuth nano-droplets for group-V based molecular-beam droplet epitaxy

  C. Li, Z. Q. Zeng, D. S. Fan, Y. Hirono, J. Wu, T. A. Morgan, X. Hu, S. Q. Yu, Zh. M. Wang, G. J. Salamo
  [show abstract] [hide abstract]
  ABSTRACT: Self-assembly of bismuth droplets at nanoscale on GaAs(100) surface using molecular beam epitaxy was demonstrated. Fine control of density and size was achieved by varying growth temperature and total bismuth deposition. Droplet density was tuned by roughly 3 orders of magnitude, and the density-temperature dependence was found to be consistent with classical nucleation theory. These results may extend the flexibility of droplet epitaxy by serving as templates for group V based droplet epitaxy, which is in contrast to conventional group III based droplet epitaxy and may encourage nanostructure formation of bismuth-containing materials.
  Applied Physics Letters 12/2011; 99(24):243113-243113-3. · 3.84 Impact Factor
• Source

  Available from: Vitaliy G Dorogan

  Article: Optical evidence of a quantum well channel in low temperature molecular beam epitaxy grown Ga(AsBi)/GaAs nanostructure.

  Yu I Mazur, V G Dorogan, M Schmidbauer, G G Tarasov, S R Johnson, X Lu, S-Q Yu, Zh M Wang, T Tiedje, G J Salamo
  [show abstract] [hide abstract]
  ABSTRACT: A Ga(AsBi) quantum well (QW) with Bi content reaching 6% and well width of 11 nm embedded in GaAs is grown by molecular beam epitaxy at low temperature and studied by means of high-resolution x-ray diffraction, photoluminescence (PL), and time-resolved PL. It is shown that for this growth regime, the QW is coherently strained to the substrate with a low dislocation density. The low temperature PL demonstrates a comparatively narrow excitonic linewidth of ∼ 40 meV. For high excitation density distinct QW excited states evolve in the emission spectra. The origins of peculiar PL dependences on temperature and excitation density are interpreted in terms of intra-well optical transitions.
  Nanotechnology 09/2011; 22(37):375703. · 3.98 Impact Factor