【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 .0 2更多还原

【Abstract】 The 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.更多还原