Persistent photoconductivity of GaAs/AlGaAs heterostructures has hampered the measurement of charge- and spin-related quantum effects in gate-defined quantum devices and integrated charge sensors due to Si-dopant-related deep donor levels (DX centers). In this study, this effect is overcome by using an undoped GaAs/AlGaAs heterostructure for photonic purposes. We also measure the electron transport before and after LED illumination at low temperatures. In addition to a regular rapid saturation showing the increased carrier density, a slow accumulation of illumination effects appeared when different top-gate voltages were applied during illumination, which indicated the redistribution of charge at the oxide–GaAs interface. This study provides interesting insights into the development of optically stable devices for efficient semiconductor quantum interfaces.
Distinguishing persistent effects in an undoped GaAs/AlGaAs quantum well by top-gate-dependent illumination
Takafumi Fujita, Ryota Hayashi, Makoto Kohda, Julian Ritzmann, Arne Ludwig, Junsaku Nitta, Andreas D. Wieck, Akira Oiwa; Distinguishing persistent effects in an undoped GaAs/AlGaAs quantum well by top-gate-dependent illumination. J. Appl. Phys. 21 June 2021; 129 (23): 234301. https://doi.org/10.1063/5.0047558
Download citation file: