空间GaInP/GaAs/Ge三结太阳电池结构参数对电学性能影响机理研究

Study on the Influence Mechanism of Spatial GaInP/GaAs/Ge Three-Junction Solar Cell Structural Parameters on Electrical Performance

摘要: 本文使用计算机模拟了三结GaInP/GaAs/Ge太阳电池，通过改变顶电池GaInP、中电池GaAs厚度以及掺杂浓度等结构参数，得出了电池的光生载流子收集效率和电学特性之间的规律，揭示了太阳电池结构参数对电学性能影响的内在物理机制。结果表明，发射区厚度变化主要影响短波区域，基区厚度变化主要影响长波区域。顶电池GaInP发射区厚度增加，短路电流、开路电压先增后降；基区厚度增加，短路电流降低，最大功率随短路电流的变化而变化。中电池GaAs厚度增大，短路电流整体呈降低趋势，开路电压略有升高。GaInP工作区掺杂浓度升高，电学性能几乎不发生改变；GaAs工作区掺杂浓度升高，开路电压略有增加，短路电流和最大功率均呈下降趋势。可见GaInP的掺杂浓度对电池的影响远远低于GaAs。

Abstract: This article uses computer simulation of a three-junction GaInP/GaAs/Ge solar cell. By changing the structural parameters of thickness and doping concentration of the top cell GaInP and middle cell GaAs, the relationship between the photogenerated carrier collection efficiency and electrical properties of the cell is obtained, revealing the inherent physical mechanism of the influence of solar cell structural parameters on electrical performance. The results indicate that the thickness variation of the emission zone mainly affects the shortwave region, while the thickness variation of the base zone mainly affects the longwave region. As the thickness of the GaInP emission zone in the top cell increases, the short-circuit current and open-circuit voltage first increase and then decrease; as the thickness of the base zone increases, the short-circuit current decreases, and the maximum power follows the variation of the short-circuit current. As the thickness of GaAs in the middle cell increases, the overall short-circuit current shows a decreasing trend, while the open-circuit voltage slightly increases. As the doping concentration in the GaInP working area increases, the electrical performance remains almost un-changed; as the doping concentration in the GaAs working area increases, the open-circuit voltage slightly increases, while the short-circuit current and maximum power both show a decreasing trend. It can be seen that the doping concentration of GaInP has a much lower impact on the cell than that of GaAs.