Photoconductivity in AlSb/InAs quantum wells

Abstract

Measuring photoconductivity at low temperatures, we investigate the recently observed bipolar behaviour of the pemistent photoeffect in InAs/AISb quantum wells. Depending upon the incident wavelength we observe either a persistent increase or a persistent decrease of the carrier density in the well. We discuss our experimental findings in terms of a simple model based on the band structure as known to date and the growth parameters of the heterostructure.

Effect of electron-electron interaction on cyclotron resonance in high-mobility InAs/AlSb quantum wells

“…This paper presents experimental results, obtained by CR technique in InAs/AlSb QWs with electron mobility up to 5.5 Â 10 5 cm 2 /V s, which significantly exceed the mobility values in the samples of InAs/AlSb QWs studied previously. [24][25][26][27][28][29][30][31][32][33] The top quality of our samples was also confirmed by observing pronounced triple splitting of CR line for transitions with partially filled LLs. In the range of filling factors 3 < < 4, the samples with different QW widths and electron concentrations demonstrate similar "enhanced" splitting of CR lines.…”

Zero-field spin splitting in InAs-AlSb quantum wells revisited

“…An expected zero-field spin splitting should depend on the effective electric field across the quantum well. Since we found it difficult to fabricate reliably functioning gates, we varied the carrier density and with it the effective electric field in the 2DEG via the persistent pho-toconductivity effect [15]. We used a red LED to illuminate the sample.…”

Optical tuning of the charge carrier type in the topological regime of InAs/GaSb quantum wells

“…We attribute the optical tunability to the interplay of negative persistent photoconductivity and the buildup of photogenerated charge carriers on the surface and substrate side of the device, respectively. Quantum well heterostructures composed of 6.1Å family semiconductors exhibit positive and negative persistent photoconductivity, depending on the utilized material, material composition, heterostructure layout, and photon energy [32][33][34][35][36][37][38][39][40]. In Refs.…”

“…In Refs. [33,36,37], the authors study the evolution from positive to negative photoconductivity 041301-3 of AlSb/InAs/AlSb quantum wells dependent on the incident light energy. For photon energies above ≈1.55 eV, the authors show negative persistent photoconductivity which they attribute to photogenerated holes in the GaSb cap.…”

“…For lower photon energies, this process is absent (see Ref. [33]) as the hole tunneling time exceeds the recombination time and the photogenerated electron-hole pairs recombine. The electrons are trapped within ionized donors in the GaSb cap region [33].…”