分子束外延生长的InAs/GaAs自组织量子点发光特性  

Light Emission Characteristics of Self-organized Quantum Dot of InAs/GaAs Grown at the Edge of Molecular Beam

作　　者：孙彦[1] 方志丹[2] 龚政[2] 苗振华[2] 牛智川[2] 

机构地区：[1]大同大学物理系,大同037009 [2]中国科学院半导体研究所,北京100083

出　　处：《人工晶体学报》2005年第2期384-386,共3页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No. 60176006;No. 90201026);中国科学院纳米科学与技术项目资助

摘　　要：研究了分子束外延生长的覆盖了1nm的InxAl1 xAs(x=0. 2, 0. 3 )和3nm的In0. 2Ga0. 8As复合应力缓冲层InAs/GaAs自组织量子点(QD)光致发光(PL)特性。加InAlAs层后PL谱红移到1. 33μm,室温下基态和第一激发态间的跃迁能级差增加到86meV。高In组份的InAlAs有利于获得较长波长和较窄的半高宽(FWHM)。对于覆盖复合应力缓冲层的QD不会使波长和FWHM发生显著变化,但可以使基态和第一激发态间的能级差进一步增大。这些结果归因于InAlAs能够有效的抑制In的偏析,减少应力,使QD保持较高的高度。同时,由于InAlAs具有较高的限制势垒,可以增加基态和第一激发态间的能级差。The photon induced fluorescence light (PL) emission characteristics of self-organized quantum dot (QD) at the combined stress buffer layers of InxAl1-xAs (x = 0.2, 0.3) covering 1 nm and In0.2Ga0.8As covering 3 nm, which were grown at the edge of molecular beam, were studied. When adding InAlAs layer, PL spectrum shifts to 1.33 μm, the transition energy difference between the ground state and the first excited state increased to 86 meV at room temperature. InAlAs with high percentage of In is in favor of getting a longer wavelength and a narrower line width (FWHM). For QD covering the combined stress buffer layer it makes no obvious difference to the wavelength and the line width (FWHM), but will increase the energy difference between the ground and the first excited states. These results are due to that InAlAs can effectively suppress the aisotropicity of In, therefor reducing the stress, and keeping the height of QD relatively high. Because of InAlAs having a relatively high restrict potential barrier, the energy difference between the ground and the first excited states can be increased.

关 键 词：分子束 外延生长工艺 INAS GAAS 发光特性 光致荧光谱 应力缓冲层 量子点 

分 类 号：O471.1[理学—半导体物理]