Structural Dependences of Localization and Recombination of Photogenerated Carriers in the top GaInP Subcells of GaInP/GaAs Double-Junction Tandem Solar Cells
Structural Dependences of Localization and Recombination of Photogenerated Carriers in the top GaInP Subcells of GaInP/GaAs Double-Junction Tandem Solar Cells
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GaInP/GaAs 双结串联太阳能电池顶部 GaInP 子电池中光生载流子的局域化和复合的结构依赖性
DOI：
10.1021/am506976n
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发表时间：
2015
影响因子：
9.5
通讯作者：
Yang Hui
中科院分区：
文献类型：
--
作者：
Deng Zhuo;Ning Jiqiang;Su Zhicheng;Xu Shijie;Xing Zheng;Wang Rongxin;Lu Shulong;Dong Jianrong;Zhang Baoshun;Yang Hui
在高效 GaInP/GaAs 双结串联太阳能电池中，GaInP 层在决定太阳能电池的性能方面发挥着核心作用。因此，深入了解GaInP层的光电过程对于提高GaInP基光伏器件的能量转换效率至关重要。在这项工作中，我们坚定地证明了 GaInP/GaAs 双结串联太阳能电池中顶部 GaInP 子电池中光生载流子的局域化和复合对基板取向误差角的强烈依赖性，以及激发强度和温度依赖性光致发光（PL）。包括GaInP层的整个太阳能电池结构是通过金属有机化学气相沉积在GaAs衬底上生长的，其取向角为2°（表示为样品2°）和7°（样品7°）偏离（100）朝向（111）B。两个顶部 GaInP 子电池的 PL 光谱特征及其激发功率和温度依赖性在取向差角上表现出显着的变化。在样品2°中，主要的局域机制和发光通道是由于高度有序的原子域引起的能量势最小值；在样品7°中，光生载流子的主要局域化和辐射复合发生在原子无序区域。我们的研究结果揭示了顶部 GaInP 子电池中光生载流子的定位和复合机制的更精确图像，这可能是控制基于 GaInP 的多结光伏器件光电效率的关键因素。
In high-efficiency GaInP/GaAs double-junction tandem solar cells, GaInP layers play a central role in determining the performance of the solar cells. Therefore, gaining a deeper understanding of the optoelectronic processes in GaInP layers is crucial for improving the energy conversion efficiency of GaInP-based photovoltaic devices. In this work, we firmly show strong dependences of localization and recombination of photogenerated carriers in the top GaInP subcells in the GaInP/GaAs double-junction tandem solar cells on the substrate misorientation angle with excitation intensity- and temperature-dependent photoluminescence (PL). The entire solar cell structures including GaInP layers were grown with metalorganic chemical vapor deposition on GaAs substrates with misorientation angles of 2° (denoted as Sample 2°) and 7° (Sample 7°) off (100) toward (111)B. The PL spectral features of the two top GaInP subcells, as well as their excitation-power and temperature dependences exhibit remarkable variation on the misorientation angle. In Sample 2°, the dominant localization mechanism and luminescence channels are due to the energy potential minima caused by highly ordered atomic domains; In Sample 7°, the main localization and radiative recombination of photogenerated carriers occur in the atomically disordered regions. Our results reveal a more precise picture on the localization and recombination mechanisms of photogenerated carriers in the top GaInP subcells, which could be the crucial factors in controlling the optoelectronic efficiency of the GaInP-based multijunction photovoltaic devices.