【摘要】 研究了GaSb/GaAs复合应力缓冲层上自组装生长的InAs量子点.在2MLGaSb/1MLGaAs复合应力缓冲层上获得了高密度的、沿[100]方向择优分布量子点.随着复合应力缓冲层中GaAs层厚度的不同,量子点的密度可以在1.2×1010cm-2和8×1010cm-2进行调控.适当增加GaAs层的厚度至5ML,量子点的发光波长红移了约25nm,室温下PL光谱波长接近1300nm.更多还原

【Abstract】 Optical properties and surface structures of InAs/GaAs serf-assembled QDs grown on 2ML GaSb and x-ML GaAs combined strain-buffer layer are investigated systematically by photoluminescence(PL) and atomic force microscopy(AFM).The QD density varies from 1.2×10cm -2 to 8.0×10cm -2 due to the influence of the lattice mismatch.The combined layer favors the increasing of In incorporated into dots and the average height-to-width ratio,which resulted in the red-shift of the emission peaks.For the sample of 5ML GaAs thin film the ground state transition is shifted to nearly 1300nm at room temperature.更多还原