不同尺寸分布的自组织In_(0.55)Al_(0.45)As/Al_(0.5)Ga_(0.5)As量子点的静压光谱  

Photoluminescence of In_(0.55)Al_(0.45)As/Al_(0.5)Ga_(0.5)As Quantum Dots with Multi\|Modal Size Distribution Under Hydrostatic Pressure\+*

作　　者：陈晔[1] 张旺[1] 李国华[1] 韩和相[1] 汪兆平[1] 周伟[2] 王占国[2] 

机构地区：[1]中国科学院半导体研究所半导体超晶格国家重点实验室,北京100083 [2]中国科学院半导体研究所材料科学实验室,北京100083

出　　处：《Journal of Semiconductors》2000年第11期1092-1098,共7页半导体学报（英文版）

基　　金：国家自然科学基金资助项目 !697760 1 2 &&

摘　　要：在 1 5K测量了不同尺寸分布的 In0 .55Al0 .4 5As/Al0 .5Ga0 .5As量子点的静压光致发光 ,静压范围为 0 - 1 .3GPa.常压下观察到三个发光峰 ,分别来源于不同尺寸的量子点 (横向直径分别为2 6、52和 62 nm)的发光 .它们的压力系数分别为 82、94和 98me V/GPa,都小于 In0 .55Al0 .4 5As体材料带边的压力系数 ,特别是尺寸为 2 6nm的小量子点比 In0 .55Al0 .4 5As体材料带边小 1 7% ,并且压力系数随量子点尺寸的变小而减小 .理论计算表明有效质量的增大和 Γ- X混合是量子点压力系数变小的主要原因 ,并得到横向直径为 2 6和 52 nm的小量子点的 Γ- X混合势为 1 5和1 0 me V.根据实验还确定 In0 .55Al0 .4 5As/Al0 .5Ga0 .5As量子点系统 X能带具有 类结构 ,并且估算出价带不连续量为 0 .1 5± 0 .0The photoluminescence spectra of In 0.55 Al 0.45 As/Al 0.5 Ga 0.5 As self\|assembled Quantum Dots (QD) with multi\|modal distribution were performed under hydrostatic pressure (0—1.3GPa).Three peaks are observed in the spectra,which comes from different dot families.The measured pressure coefficients are 82,94 adn 98meV/GPa for the peaks of dots with average lateral size of 26,52 and 62nm, respectively.The are all smaller than that of the Γ \|point band gap in bulk In 0.55 Al 0.45 As,especially for peak D 1,which is about 17% smaller.And the pressure coefficients decrease with the decrease of the dot size.Theoretic calculation indicates that the increase of the effective mass and Γ\|X mixing are the main reasons for the decrease of the pressure coefficients,and the Γ\|X mixing is more important in the small dots.The obtained Γ\|X interaction potential are 15 and 10meV for 26 and 52nm QDs.A type\|Ⅱ alignment for X conductor band in In 0.55 Al 0.45 As/Al 0.5 Ga 0.5 As QD system is obtained from the analyses of the experiment data.The valence offsets Q \-v are estimated as 0 15±0 02.

关 键 词：ALGAAS INALAS 量子点 光致发光 静压光谱 

分 类 号：O472[理学—半导体物理]