Fe b 20 03 Field - Effect Persistent Photoconductivity in AlAs / AlGaAs and GaAs / AlGaAs Quantum Wells
نویسندگان
چکیده
We report a persistent increase or decrease in the two-dimensional electron density of AlAs or GaAs quantum wells flanked by AlGaAs barriers, brought about by illuminating the samples at T ∼ 4 K while simultaneously applying a voltage bias between a back gate and the two-dimensional electron gas. Control of the final carrier density is achieved by tuning the back gate bias during illumination. Furthermore, the strength of the persistent photoconductivity depends on the Al mole fraction in the back Al x Ga 1−x As barrier, and is largest at x ≃ 0.4.
منابع مشابه
The Effect of Structural Parameters on the Electronic States and Oscillator Strength of a Resonant Tunneling Quantum Well Infrared Photodetector
In this paper a resonant tunnelling quantum well infrared photodetector (RT-QWIP) is discussed. Each period of this photodetector structure comprises of a resonant tunnelling structure (AlAs/AlGaAs/AlAs) nearby a quantum well (AlGaAs/GaAs). In this photodetector, photocurrent is produced when an electron makes a transition from the ground state of the well to an excited state which is coupled t...
متن کاملEffect of an in-plane magnetic field on microwave photoresistance and Shubnikov-de Haas effect in high-mobility GaAs/AlGaAs quantum wells
A recent study of the decay of microwave-induced resistance oscillations (MIRO) in GaAs/AlGaAs quantum wells due to an in-plane magnetic field B‖ has revealed the dominant role of a quadratic-in-B‖ correction to the quantum scattering rate. In the present study, we examine the evolution of Shubnikov-de Haas oscillations (SdHO) with increasing tilt angle in the same sample. Even though we find t...
متن کاملCathodoluminescence study of disordering of GaAs/AlGaAs quantum wells using an AlAs native oxide and thermal annealing technique
GaAs/AlGaAs quantum wells ~QWs!, selectively disordered using an AlAs native oxide and thermal annealing technique, were studied using spectrally, spatially, and temporally resolved cathodoluminescence ~CL!. The spectral shift of the QW luminescence was determined as a function of annealing temperature in the oxide and nonoxide regions. Time-resolved CL was used to assess the impact of defects ...
متن کاملOptimization of AlAs/AlGaAs quantum well heterostructures on on-axis and misoriented GaAs (111)B
We report systematic growth optimization of high Al-content AlGaAs, AlAs, and associated modulation-doped quantum well (QW) heterostructures on on-axis and misoriented GaAs (111)B by molecular beam epitaxy. Growth temperatures TG> 690 C and low As4 fluxes close to group III-rich growth significantly suppress twin defects in high-Al content AlGaAs on on-axis GaAs (111)B, as quantified by atomic ...
متن کاملIntervalley Scattering and the Role of Indirect Band Gap AlAs Barriers: Application to GaAs/AlGaAs Quantum Cascade Lasers
We report on the results of our simulations of Γ−X scattering in GaAs/AlGaAs heterostructures, discussing the importance of the mole fraction, doping density, and lattice and electron temperature in determining the scattering rates. We consider three systems, a single quantum well (for the investigation of Γ−X scattering), a double quantum well (to compare the Γ−X−G and Γ−Γ scattering rates), a...
متن کامل