Luminescence study of Si/Ge quantum dots

被引：6

作者：

Larsson, M ^{[1
]}

Elfving, A ^{[1
]}

Holtz, PO ^{[1
]}

Hansson, GV ^{[1
]}

Ni, WX ^{[1
]}

机构：

[1] Linkoping Univ, Dept Phys, SE-58183 Linkoping, Sweden

来源：

PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES | 2003年 / 16卷 / 3-4期

关键词：

quantum dots; photoluminescence; band alignment; silicon-germanium;

D O I：

10.1016/S1386-9477(02)00652-5

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

We present a photoluminescence (PL) study of Ge quantum dots embedded in Si. Two different types of recombination processes related to the Ge quantum dots are observed in temperature-dependent PL measurements. The Ge dot-related luminescence peak near 0.80 eV is ascribed to the spatially indirect recombination in the type-II band lineup, while a high-energy peak near 0.85 eV has its origin in the spatially direct recombination. A transition from the spatially indirect to the spatially direct recombination is observed as the temperature is increased. The PL dependence of the excitation power shows an upshift of the Ge quantum dot emission energy with increasing excitation power density. The blueshift is ascribed to band bending at the type-II Si/Ge interface at high carrier densities. Comparison is made with results derived from measurements on uncapped samples. For these uncapped samples, no energy shifts due to excitation power or temperatures are observed in contrast to the capped samples. (C) 2002 Elsevier Science B.V. All rights reserved.

引用

页码：476 / 480

页数：5

共 7 条

[1] TYPE-II BAND ALIGNMENT IN SI/SI1-XGEX QUANTUM-WELLS FROM PHOTOLUMINESCENCE LINE SHIFTS DUE TO OPTICALLY INDUCED BAND-BENDING EFFECTS - EXPERIMENT AND THEORY [J].