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采用高分辨透射电子显微图像(HRTEM)、光致发光谱(PL)和原子力显微镜(AFM)技术等研究了金属有机化学气相沉积(MOVPE)技术制备的Ge基Ga In P异质外延层的结构和光学性质.研究表明,Ga In P带边发光峰能量位置随温度变化的倒“S”型变化来源于局域态和本征态发光之间的竞争;同时,实验中观察到了由[Ge(Ga,In)-V(Ga,In)]络合物所引起的1.4 e V左右的宽发光峰.不同偏角衬底的Ga In P外延层的变温PL谱和AFM分析表明,9°偏角的Ge衬底上生长的Ga In P外延层的有序度比6°偏角时减小,表面形貌更为平整.此外,Ge衬底和Ga In P之间插入超薄Al As层会增加Ga In P材料的有序度.当Al As界面层厚度由0.5 nm增加到5 nm时,观察到了由于应力增加所导致的Ga In P材料有序度的增加,从而导致载流子弛豫时间增加且呈双指数规律衰减.在Ge/Al As/Ga In P结构中,100 K下的PL谱中出现了与P空位相关的1.57 e V左右宽发光峰,并且该发光峰强度随Al As界面层厚度的增加而增强.
High-resolution transmission electron microscopy (HRTEM), photoluminescence (PL) and atomic force microscopy (AFM) techniques were used to investigate the Ge-based Ga In P heteroepitaxial layers prepared by metal organic chemical vapor deposition (MOVPE) Structure and optical properties.The results show that the variation of the energy position of the Ga In P band edge with temperature changes from the competition between the localized state and the eigenstate emission.At the same time, Wide emission peak around 1.4 e V caused by [Ge (Ga, In) -V (Ga, In)] complex.The temperature-changing PL spectra and AFM analysis of Ga In P epitaxial layers with different off-angle substrates , The epitaxial layer of Ga In P grown on Ge substrate with a declination angle of 9 ° decreases more than the declination angle of 6 ° and the surface morphology is more smooth.In addition, The thin AlAs layer increases the orderliness of the GaInP material.When the thickness of the AlAs interface layer increases from 0.5 nm to 5 nm, an increase in the ordering of the GaInP material due to the increase in stress is observed resulting in The carrier relaxation time increases with a double exponential decay.In the Ge / Al As / Ga In P structure, a broad band of about 1.57 e V is observed in the PL spectrum at 100 K Light peak, and the intensity of the emission peak increases as the thickness of the AlAs interface layer increases.