Excitons at a single localized center induced by a natural composition modulation in bulk Ga0.5In0.5P
Excitons at a single localized center induced by a natural composition modulation in bulk Ga0.5In0.5P
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DOI：
10.1103/physrevb.61.16040
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发表时间：
2000-06
影响因子：
3.7
通讯作者：
M. Sugisaki;H. Ren;K. Nishi;S. Sugou;Y. Masumoto
中科院分区：
文献类型：
--
作者：
M. Sugisaki;H. Ren;K. Nishi;S. Sugou;Y. Masumoto
报道了用气体源分子束外延生长的Ga0.5In0.5P薄膜的光学特性。在宏观和微观光致发光谱中观察到由于Ga和In的自发横向成分调制而引起的强烈的光学各向异性。微PL研究表明，PL带是由尖锐的线所产生的辐射衰减的激子被困在局部潜在的最小值所造成的组成调制。还观察到PL上升和衰减时间的各向异性。通过考虑激子从浅陷阱到深陷阱的弛豫过程，很好地解释了PL衰减时间与探测能量的关系。
Optical properties of Ga 0.5 In 0.5 P grown by gas-source molecular beam epitaxy are reported. A strong optical anisotropy due to the spontaneous lateral composition modulation of Ga and In was observed in macro-and micro-photoluminescence (PL) spectra. The micro-PL study revealed that the PL band is composed of sharp lines that arise from the radiative decay of excitons trapped at local potential minima caused by the composition modulation. Anisotropy in PL rise and decay times was also observed. The detection energy dependence of the PL decay time is well explained by considering the relaxation process of excitons from shallow traps to deep traps.