Analysis of electric-field domain formations and carrier transport phenomena in GaAs/AlAs asymmetric double-quantum-well superlattices

Abstract

Abstract We evaluated the formation of electric-field domains (EFDs) in three kinds of asymmetric double-quantum-well (ADQW) superlattices (SLs) whose photoluminescence (PL) properties revealed various characteristics affected by EFD formation. In particular, anomalous comb-shaped PL branches were clearly observed. Each PL branch corresponds to one EFD, giving important information on EFD distribution in ADQW-SLs. We determined the strengths of all electric-fields in all the EFDs from their redshifted PL signals and plotted their reverse bias voltage dependence. We clearly identified the EFD distributions in the ADQW-SLs in which the resonant tunneling effect plays an important role to make carrier transport paths. These results demonstrate that the analysis of EFD distributions from PL properties is an effective tool to investigate the carrier transport phenomena in biased SLs.