Open AccessStudy of optical properties in GaAs1-xSbx/GaAssingle quant um wells
Author(s) -
罗向东,
边历峰,
徐仲英,
罗海林,
王玉琦,
王建农,
葛惟琨
Publication year - 2003
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.52.1761
Subject(s) - quantum well , heterojunction , excitation , excited state , photoluminescence , materials science , molecular beam epitaxy , epitaxy , condensed matter physics , valence band , optoelectronics , atomic physics , band gap , physics , optics , laser , nanotechnology , quantum mechanics , layer (electronics)
GaAsSb/GaAs single quantum wells (SQWs) grown by molecular beam epitaxy are studied by selectively-excited photoluminescence (SEPL) measurement. For the first time, we have simultaneously observed the PL from both type Ⅰ and type Ⅱ transitions in GaAsSb/GaAs heterostructure in the SEPL. The two transitions exhibit different PL behaviours under different excitation energy. As expected, the peak energy of type I emission remains constant in the whole excitation energy range we used, while type Ⅱ transition shows a significant blue shift with increasing excitation energy.The observed blue shift is well explained in terms of electron-hole charge separation model at the interface. Time-resolved(TR) PL exhibits more type Ⅱ characteristic of GaAsSb/GaAs QW. Moreover, the results of the excitation-power-dependent PL and TRPL provide more direct information on the type-Ⅱ nature of the band alignment in GaAsSb/GaAs quantum-well structures. By combining the experimental results with some simple calculations, we have obtained the strained and unstrained valence band offsets of Qv1.145 and Q0v0.76 in our samples, respectively.