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Full-Text Articles in Physics
Emission Processes Of The Interaction Between The Quantum Well And Donor Delta Layer In Heterostructures For Phemts, Yana Ivanova, George Yakovlev, Vasily Zubkov, Anna Solomnikova
Emission Processes Of The Interaction Between The Quantum Well And Donor Delta Layer In Heterostructures For Phemts, Yana Ivanova, George Yakovlev, Vasily Zubkov, Anna Solomnikova
Turkish Journal of Physics
We present experimental and theoretical investigations of pHEMT heterostructures with AlGaAs/InGaAs/GaAs quantum wells (QWs) and/or a delta-doped layer, which can be used as active regions in transistors operating in the 4-18 GHz frequency range. Using the electrochemical capacitance-voltage setup ECV Pro we, for the first time, experimentally observed a concentration peak from the near-surface delta layer of the pHEMT structure together with a peak of QW enrichment. The capacitance of the electrolyte-semiconductor contact was measured by Agilent LCR-meter, which was connected to the electrochemical cell of ECV Pro through a specially designed relay module. Using numerical simulation of the electronic …
Electrochemical Capacitance-Voltage Profiling Of Nonuniformly Doped Gaas Heterostructures With Sqws And Mqws For Led Applications, George Yakovlev, Vasily Zubkov, Anna Solomnikova, Oleg Derevianko
Electrochemical Capacitance-Voltage Profiling Of Nonuniformly Doped Gaas Heterostructures With Sqws And Mqws For Led Applications, George Yakovlev, Vasily Zubkov, Anna Solomnikova, Oleg Derevianko
Turkish Journal of Physics
Light-emitting heterostructures with single and multiple GaAs/InGaAs quantum wells have been investigated by means of electrochemical capacitance-voltage (ECV) profiling. Capacitance-voltage characteristics were measured; concentration profiles of free charge carriers over the heterostructure depth as well as the intensity of quantum well filling by charge carriers were obtained. In heterostructures with a single quantum well (QW), we considered limitations of capacitance techniques for undoped QW profiling, which are situated near the metallurgic border of the p-n junction. We made a detailed consideration of phenomena related to Debye smearing and we developed and analyzed the dependence of the space charge region width …
Triangular Quantum Profiles: Transmission Probability And Energy Spectrum, Altuğ Arda
Triangular Quantum Profiles: Transmission Probability And Energy Spectrum, Altuğ Arda
Turkish Journal of Physics
Analytical expressions for the transition probability and the energy spectrum of the 1D Schrödinger equation with position-dependent mass are presented for the triangular quantum barrier and quantum well. The transmission coefficient is obtained by using the wave functions written in terms of Airy's functions and of the solutions of Kummer's differential equation. In order to show the validity of our analysis, an example by taking some numerical values for a GaAs heterostructure is presented.
Polaron Effects On The Second-Harmonic Generation In Asymmetrical Semiexponential Quantum Wells, Bo Xiao, Kangxian Guo, Sen Mou, Zhongmin Zhang
Polaron Effects On The Second-Harmonic Generation In Asymmetrical Semiexponential Quantum Wells, Bo Xiao, Kangxian Guo, Sen Mou, Zhongmin Zhang
Turkish Journal of Physics
Polaron effects on the second-harmonic generation (SHG) in asymmetrical semiexponential quantum wells (ASEQWs) are investigated theoretically. By using the framework of the compact-density-matrix approach and iterative method, the analytical expression of the SHG coefficients in ASEQWs is presented. Numerical results are illustrated for a typical GaAs/AlGaAs. By considering the electron--LO--phonon interaction (ELOPI), the energy levels and the wave functions of an electron confined in ASEQWs are obtained. It is found that whether we consider the ELOPI or not, the incident photon frequency $\omega$ and parameters $U_0$ and $\sigma$ also affect the SHG coefficient obviously.
Variation Of Chemical Potential Oscillations Of A 2deg In A Quantum Well Under A Magnetic Field For Multiple Sub-Band Occupation As Function Of Temperature And Level-Broadening, Berri̇n Özdemi̇r, Zeki̇ Yarar, Meti̇n Özdemi̇r
Variation Of Chemical Potential Oscillations Of A 2deg In A Quantum Well Under A Magnetic Field For Multiple Sub-Band Occupation As Function Of Temperature And Level-Broadening, Berri̇n Özdemi̇r, Zeki̇ Yarar, Meti̇n Özdemi̇r
Turkish Journal of Physics
We study the variation of chemical potential in a two dimensional electron gas in a uniform magnetic field as a function of temperature and level-broadening parameter. Schrödinger and Poisson equations are solved self-consistently for a two dimensional electron gas formed in a Ga_xAl_{1-x}As/GaAs quantum well, to numerically determine the potential profile, empty or occupied energy sub-bands, the wavefunctions and electron concentrations corresponding to each sub-band at various temperatures. Then assuming that the electron concentration is not altered, the variation of chemical potential with respect to both temperature and energy level-broadening parameter is studied under a uniform and constant magnetic field. …