部分有序(Al_xGa_(1-x))_(0.51)In_(0.49)P(x=0.29)合金的发光衰退过程  

Luminescence Decay of Partially Ordered (Al_xGa_(1-x))_(0.51)In_(0.49)P(x=0.29) Alloy

作　　者：吕毅军[1] 高玉琳[1] 郑健生[1] 蔡志岗[2] 桑海宇[2] 曾学然[2] 

机构地区：[1]厦门大学物理系,福建厦门361005 [2]中山大学超快速激光光谱学国家重点实验室,广东广州510275

出　　处：《发光学报》2002年第2期129-132,共4页Chinese Journal of Luminescence

基　　金：福建省自然科学基资助项目 (A0 110 0 0 7;A9910 0 0 4)

摘　　要：利用时间分辨光谱研究了 (AlxGa1-x) 0 51In0 4 9P合金的时间衰退过程 ,观察到载流子的转移过程和PL谱峰蓝移现象。这和变温发光谱中谱峰的Z 型依赖关系相吻合。这种现象明显表明了载流子的转移过程和子带的存在 ,证实了我们对超晶格带折叠效应的猜测。子带是由于有序结构的超晶格效应使导带的L带折叠到Γ带 ,载流子在时间衰退过程中从Γ带转移到L带。In this paper, time-resolved photoluminescence(TRPL) was applied to study the optical properties of partially ordered quaternary (Al xGa 1-x) 0.51In 0.49P(x=0.29) alloy grown by MOVPE, the process of the transfer of carriers and the blue-shift of PL peak in (Al xGa 1-x) 0.51In 0.49P(x=0.29) alloy are directly observed.Both excitation-wavelength dependence of lifetime and excitation-intensity dependence of lifetime show wide distribution of carriers along bands.In TRPL spectra measured at 77K, the PL peak almost keeps unchanged, while at 300K, the PL peak has a small blue-shift with the delay of time, which is completely opposite to the character of donor-acceptor pair (DAP). The blue-shift phenomenon apparently suggests the occurrence of transfer of carriers and is coincident with the report of the Z-shape character of the PL temperature-dependent spectra, in which an anomalous blue-shift of PL peak energy occurs between 55K and 84K. This phenomenon further indicates the existence of sub-bands which is derived from the superlattice effect of ordered structure, which is a so-called orientational superlattice structure and which is considered to be a composite of the low-band-gap ordered domains in a high-band-gap disordered matrix. Thus, this phenomenon verifies our conjecture about band-folding effect of conduction band from L band to Γ band, i.e., the carriers transfer from Γ band to L band during the decay time. The transfer of carriers between Γ and L band reveals the origin of the anomalous blue-shift in the PL temperature-dependent spectra as well. The single exponential component fitting equation suggests the same category carriers of Γ band and L band. The transfer of carriers at 300K is more apparent than that at 77K. This is because that the blue-shift effect of PL peak energy occurs during 55～84K, the luminescence is dominated by L band at 300K and it is easier for the carriers to get energy to transfer under higher temperature.

关 键 词：Ⅲ-V化合物 有序结构 光致发光 四元合金 半导体材料 发光谱 (AlxGa1-x)0.51In0.49P(x=0.29) 发光衰退过程 

分 类 号：O472.3[理学—半导体物理] TN304.23[理学—物理]