Carrier transfer between confined and localized states in type II InAs/GaAsSb quantum wells

Abstract

Temperature-resolved photoluminescence studies were performed on tenselystrained AlSb/InAs/GaAsSb W-shaped type II quantum wells. They revealed two emission bands: one at lower energy of localized origin resulting from carrier trapping states at interfaces and dominates at low-temperature; and one corresponding to the fundamental optical transition in the type II quantum well. With the temperature increase to 170-200 K the low-energy emission is quenched and the high-energy band dominates and its intensity increases, indicating carrier transfer processes between the respective states at elevated temperatures. In addition, the integrated photoluminescence intensity was measured as a function of excitation power. At high excitation regime the emission intensity of the lowenergy emission band saturated, indicating low density of states, thus confirming its localized nature. The depth of the localization potential at the InAs/GaAsSb interface was determined to be 13-15 meV.

Fourier-Transformed Temperature-Dependent Photoluminescence of GaSb-Based Resonant Tunneling Structure with GaInAsSb Absorption Layer

“…Despite the advantage of flexibility for band gap engineering, the broken-gap alignment suffers from reduction of the oscillator strength, determining the gain of the medium. Substantial work was required, comprising the methods of optical spectroscopy, in order to understand * corresponding author the complex band structure of multilayered ICLs [10][11][12]. As a result of extensive studies, the ICLs exhibit a stateof-the-art performance in the spectral region of midinfrared [13].…”