Open AccessOptical gain in PbTe/CdTe quantum dots
Author(s) -
Tianning Xu,
Huizhen Wu,
Jianxiao Si
Publication year - 2008
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.57.2574
Subject(s) - quantum dot , cadmium telluride photovoltaics , materials science , quantum dot laser , optoelectronics , charge carrier density , exciton , quantum well , laser , physics , condensed matter physics , semiconductor , semiconductor laser theory , optics , doping
A theoretical model is developed to study the optical transition and optical gain of PbTe/CdTe quantum dots. The model is based on the k·p envelope function approach, and anisotropic band structure characteristics of PbTe are taken into consideration. The relationships of optical gain of PbTe/CdTe quantum dots vs dot size and injection carrier density are given. The theoretical results suggest that PbTe/CdTe quantum dots with dot size of 15—20nm are promising materials for mid-infrared lasers, which may produce optical gain higher than 5000cm-1 when the injection carrier density ranges (0.3—3)×1018cm-3. The optical gain decreases with dot size increasing. However, higher injection carrier density is required for PbTe/CdTe quantum dots with smaller sizes (<15nm). Therefore the optimal PbTe quantum dot sizes are 15—20nm.