A5086818203- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Semiconductor Lasers and Optical Devices
- Advanced Semiconductor Detectors and Materials
- Photonic and Optical Devices
- Spectroscopy and Laser Applications
- Advancements in Semiconductor Devices and Circuit Design
- Surface and Thin Film Phenomena
- Quantum Information and Cryptography
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum optics and atomic interactions
- Semiconductor materials and devices
- Radiation Detection and Scintillator Technologies
- Spectroscopy and Quantum Chemical Studies
- Chalcogenide Semiconductor Thin Films
- Nanowire Synthesis and Applications
- Advanced Chemical Physics Studies
- Terahertz technology and applications
- Semiconductor materials and interfaces
- Quantum Dots Synthesis And Properties
- Optical Coatings and Gratings
- Magnetic properties of thin films
- Advanced Optical Sensing Technologies
- GaN-based semiconductor devices and materials
- Gyrotron and Vacuum Electronics Research
Middle East Technical University
2021-2024
Eskisehir Technical University
2021-2022
Eskişehir City Hospital
2005-2014
Anadolu University
2005-2014
Hacettepe University
2011
Sivas Cumhuriyet Üniversitesi
1996-2005
Scientific and Technological Research Council of Turkey
1993
The authors describe the noise characterization of a mid-wavelength-infrared (MWIR) photodiode based on indium arsenide and gallium antimonide (InAs/GaSb) superlattice (SL), addressing influence different passivation layers applied to surface device. MWIR InAs/GaSb SL design structure is p-i-n configuration grown by molecular beam epitaxy (001) n-GaSb substrate. SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -passivated photodiodes...
We have theoretically investigated the diffusion of donor impurities single Si δ-doped GaAs inserted into a quantum well at T=0 K. The spread is taken account in three different models: (i) uniform distribution, (ii) triangular distribution and (iii) nonuniform distribution. In this article, from Gaussian used by other authors. electronic structures were calculated solving Schrödinger Poisson equations self-consistently. also found confining potential, charge density, subband energies,...
We have theoretically investigated the electronic structure of Si δ-doped GaAs inserted into a quantum well under an applied electric field. For uniform distribution we studied influence field on donor concentration. The properties such as effective potential, density profile, subband energies, occupations and Fermi energy level been calculated by solving Schrödinger Poisson equations self-consistently. From our calculations, seen that change dependent is more pronounced at low doping high...
In this study, photomodulated reflectance (PR) technique was employed on two different quantum well infrared photodetector (QWIP) structures, which consist of n-doped GaAs wells (QWs) between undoped AlxGa1-xAs barriers with three x compositions. Therefore, the barrier profile is in form a staircase-like barrier. The main difference structures doping and concentration QWs. PR spectra were taken at room temperature using He-Ne laser as modulation source broadband tungsten halogen lamp probe...
We investigate the theoretical calculations of voltage tunable dual-band quantum-well infrared photodetector (QWIP) in long and very wavelength range (LWIR VLWIR). The detector consists two serially connected GaAs/AlGaAs stacks which have spectral responses 8.4- 14- μm wavelengths, respectively. peak responsivity shifts from 8.4 to 14 as bias is increased.
The binding energy of excitons in symmetric and asymmetric coupled double GaAs/Ga1-x Alx As quantum wells is calculated by using a variational approach. results have been obtained the presence uniform magnetic field, as function potential symmetry, size well coupling parameter wells. We show that increasing applied field one can obtain large between electrons holes which similar to change dimensions structure. This behaviour excitonic for different barrier geometries be used study these...
In this work, the effects of quantum confinement on ground state energy a correlated electron–hole pair in spherical and disc-like dot have been investigated as function size. Under parabolic potential within effective mass approximation Ritz's variational method is applied to Hylleraas-like trial wavefunction. An efficient for reducing main effort calculation terms like rehk exp(−λreh) introduced. The contribution present work introduction integral transforms which provide expectation value...
We present a theoretical investigation of GaAs/AlGaAs infrared detector consisting three asymmetric quantum wells. Each well is designed to yield absorption and photoresponse at peak wavelengths 8.2 µm, 9.5 µm 10.8 respectively. The device operation based on an intersubband bound quasi-bound transition. Asymmetry in the barriers shown give rise dependence spectral line width applied reverse bias.
We have theoretically investigated the subband structure of two coupled Si δ-doped GaAs at T = 0 K. For uniform distribution we studied influence separation between doping layers. The electronic properties such as effective potential, density profile, energies, populations and Fermi energy been calculated by solving Schrödinger Poisson equations self-consistently. In this study, seen that is quite sensitive to conclude that, if coupling layers significant, mobility electrons in very high...
Abstract We have calculated the plasmon dispersion relations in a doped double quantum well with and without exchange–correlation potential added to effective of system. The calculations were done for high low doping densities by solving Schrödinger Poisson equations self‐consistently. Our numerical results show that is quite important at donor impurities dispersions large wave vectors. On other hand, ratio subband populations n i density N D more affected densities. (© 2007 WILEY‐VCH Verlag...
Abstract In this work, a quantum well infrared photodetector structure which consists of three different thicknesses with barrier compositions producing staircase‐like conduction band profile the reputation 30 periods has been investigated. Dark current measurements have done at range from 6 K to 290 temperature. Activation energies carriers obtained temperature dependence I‐V measurements. The change activation energy bias voltage also obtained. From zero and calculated quasi Fermi energy,...