B. M. Ashkinadze

Evolution from 2DEG to Excitonic Spectra in a Modulation-Doped GaAs/AlGaAs Single Quantum Well

The magneto-photoluminescence (PL) and its excitation (PLE) spectra are studied in a single-sided modulation-doped GaAs/AlGaAs single quantum well. With lowering the two-dimensional electron gas (2DEG) density from n2d ≈ 1×1011 to 1×1010 cm—2 by optical depletion, the 2DEG–free heavy-hole spectrum transforms into an exciton-like spectrum. Cyclotron resonance at microwave frequency is used in order to measure the 2DEG parameters in the entire range of n2d. A narrow (0.6 to 0.8 meV) exciton-like PL line is observed when n2d is optically decreased to ≈1×1010 cm—2. This line shows a clear excitonic diamagnetic shift under a perpendicularly applied magnetic field (B = 0 to 4 T). Under these conditions the 2DEG microwave mobility is still high (≈1×106 cm2/Vs). The lowest energy PL line does not show trion features, and by this it differs from other reported cases.

Effect of an in-plane magnetic field on the photoluminescence spectrum of modulation-doped quantum wells and heterojunctions

The photoluminescence (PL) spectrum of modulation-doped GaAs/AlGaAs quantum wells (MDQW) and heterojunctions (HJ) is studied under a magnetic field (

Combined Optical‐Microwave Study of Electron–Exciton Dynamic Processes in Undoped GaAs/AlGaAs Quantum Wells

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Microwave radiation induced instability in photoexcited undoped GaAs

) applied parallel to the two-dimensional electron gas (2DEG) layer. The effect of

MICROWAVE-MODULATED PHOTOLUMINESCENCE OF A TWO-DIMENSIONAL ELECTRON GAS

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PHOTOLUMINESCENCE OF A HIGH MOBILITY 2DEG IN THE FRACTIONAL QUANTUM HALL EFFECT REGIME

strongly depends on the electron-hole separation (

Interband Transitions In Modulation‐doped GaAs/AlGaAs Heterostructures Under In‐plane Magnetic Field

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Microwave‐Modulated Photoluminescence of a 2D‐electron Gas in a Magnetic Field

), and we revealed remarkable

Exciton to two-dimensional electron-hole photoluminescence transitions driven by the quantum Hall effect in photoexcited heterojunctions

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Transition from two-dimensional electron-hole to geminate-exciton photoluminescence in GaAs/AlxGa1- xAs heterostructures under a high in-plane magnetic field

-induced modifications of the PL spectra in both types of heterostructures. A model considering the direct optical transitions between the conduction and valence subband that are shifted in k-space under