【摘要】 本文介绍用正电子湮没寿命和多普勒加宽技术研究750—950℃掺Te液相外延生长的和1238℃熔体生长的GaAs晶体生长缺陷。在800—1238℃生长的晶体中都观测到312±11 ps的寿命组分π₂,其强度I₂,多普勒加宽S参数和按捕获模型计算的平均寿命τ都随晶体生长温度增高而增大。在掺Te外延晶体中,312ps寿命的正电子陷阱浓度随晶体生长温度增高而线性地增大,在熔体生长晶体中,该陷阱浓度低得多,远偏离以上线性关系。312 ps寿命归因于正电子在Ga空位湮没寿命,结果显示出掺Te在GaAs晶体中诱导Ga空位。更多还原

【Abstract】 The defects in GaAs grown with the melt growth method at 1238°C and with theTe-doped LPE method in the temperature range 750--950°C are studied by positron an-nihilation. The lifetime component τ₂ exhibits a constant value of 312±11 ps in thetemperature range 800--1238°C. The intensity I₂ increases with the growth tempera-ture. In the Te-doped LPE crystals, the concentration of the positron trap increaseslinearly with temperature. The trap is considered as Ga vacancy. The results show thatdoped Te in GaAs induces Ga vacancy.更多还原