【摘要】 利用喇曼散射方法在77K温度下对不同淀积厚度的InAs/GaAs量子点材料进行了研究.在高于InAs体材料LO模的频率范围内观察到了量子点的喇曼特征峰,分析表明应变效应是影响QD声子频率的主要因素.实验显示,随着量子点层淀积厚度L的增加,InAs量子点的声子频率由于应变释放发生红移.在加入InAlAs应变缓冲层的样品中,类AlAs声子峰随L增大发生了蓝移,从侧面证实了InAs量子点层的应变释放过程.更多还原

【Abstract】 The Raman scattering of InAs/GaAs self-assembled quantum dots(QDs) with different InAs thicknesses is investigated.The vibrational mode,which can be assigned to QD phonons,is observed.Analysis indicates that strain is the most important factor that influences the InAs QD frequency.As the InAs deposition thickness L increases,the InAs-like LO mode frequency decreases,which we attribute to the relaxation of the strain in the QD layer.In another sample with an InAlAs strain buffer layer,the AlAs-like LO mode shows a blue shift as L increases.This also supports the proposed strain relaxation process in QDs.更多还原