摘要
研究了不同In组分的InxGa1-xAs(0≤x≤ 0 3)覆盖层对自组织InAs量子点的结构及发光特性的影响 .透射电子显微镜和原子力显微镜表明 ,InAs量子点在InGaAs做盖层时所受应力较GaAs盖层时有所减小 ,并且x =0 3时 ,InGaAs在InAs量子点上继续成岛 .随x值的增大 ,量子点的光荧光峰红移 ,但随温度的变化发光峰峰位变化不明显 .理论分析表明InAs量子点所受应力及其均匀性的变化分别是导致上述现象的主要原因 .
InAs self\|assembled quantum dots(QDs) covered by 3\|nm\|thick In x Ga \{1 -x \}As(0≤ x ≤0.3) capping layer have been grown on GaAs(100) substrate.Transmission electron microscopy shows that InGaAs layer reduces the strain in the InAs islands,and atomic force microscopy evidences the deposition of InGaAs on the top of InAs islands when x =0.3.The significant redshift of the photoluminescence (PL) peak energy and the reduction of PL linewidth of InAs quantum dots covered by InGaAs are observed.In addition,InGaAs overgrowth layer suppresses the temperature sensitivity of PL peak energy.Based on our analysis,the strain\|reduction and the size distribution of the InAs QDs are the main cause of the redshift and temperature insensitivity of the PL respectively.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第11期2230-2234,共5页
Acta Physica Sinica
基金
国家攀登计划!(批准号 :1982 3 0 0 1)
和国家自然科学基金!(批准号 :697760 16)资助的课题&&
关键词
量子点
盖层
应力
红移
砷化铟
半导体
quantum dots, cap layer, strain\|reducing, redshift
