REDUCED QUANTUM EFFICIENCY OF A NEAR-SURFACE QUANTUM-WELL

Citation
Yl. Chang et al., REDUCED QUANTUM EFFICIENCY OF A NEAR-SURFACE QUANTUM-WELL, Journal of applied physics, 74(8), 1993, pp. 5144-5148
Citations number
27
Categorie Soggetti
Physics, Applied
Journal title
ISSN journal
00218979
Volume
74
Issue
8
Year of publication
1993
Pages
5144 - 5148
Database
ISI
SICI code
0021-8979(1993)74:8<5144:RQEOAN>2.0.ZU;2-7
Abstract
The effect of the proximity of a bare barrier surface on the quantum e fficiency of underlying GaAs/Al0.3Ga0.7As and In0.13Ga0.87As/GaAs quan tum wells (QWs) is studied by low-temperature photoluminescence. The q uantum efficiency of the resonantly excited QWs diminishes with decrea sing surface barrier thickness; the onset of the reduction in quantum efficiency of the InGaAs QW occurs for a barrier that is 50 angstrom t hicker than for the GaAs QW. A simple model of carrier tunneling to th e surface is formulated to explain the dependence of the quantum effic iency on surface barrier thickness and well width and height. This mod el shows good agreement with both sets of experimental data.