摘要
在低温15K和0～9GPa范围内对厚度为7.3nm、横向尺寸为78nm的自组织InAs/GaAs量子点进行了压力光谱研究.观测到大量子点的基态与第一激发态发光峰,其压力系数只有69和72meV/GPa,比小量子点的压力系数更小.基于非线性弹性理论的分析表明失配应变与弹性系数随压力的变化是大量子点压力系数小的主要原因之一.压力实验结果还表明大量子点的第一激发态发光峰来源于电子的第一激发态到空穴的第一激发态的跃迁.
The photoluminescence of self-assembled InAs/GaAs quantum dots, which are 7.3nm in height and 78nm in base size, was investigated at 15K under hydrostatic pressures up to 9GPa. The emissions from both the ground and the first excited states in large InAs dots were observed. The pressure coefficients of the two emissions are 69 and 72 meV/GPa respectively, which are lower than those of small InAs/GaAs dots. The analysis based on a nonlinear elasticity theory reveals that the small pressure coefficients mainly result from the changes of the misfit strain and the elastic constants with pressure. The pressure experiments suggest that the excited state emissions originate from the optical transitions between the first excited electron states and the first excited hole states.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第3期207-212,共6页
Journal of Infrared and Millimeter Waves
基金
国家自然科学基金(60076012
60176006)
国家重点基础研究发展计划(973计划)(G2001CB3095)
中国科学院纳米科学与技术资助项目.
关键词
凝聚态物理学
光致发光
压力
砷化铟
量子点
condensed matter physics
photoluminescence
pressure
InAs
quantum dots
