聚光型砷化镓太阳能电池芯片栅线占空比研究

Research on Optimization of Grid Shadowing Ratio for Concentrator GaAs Solar Cells

摘要: 为优化柔性衬底聚光型砷化镓太阳电池的正面电极结构，本文系统研究了栅线占空比对电池性能的影响机制。采用柔性芯片剥离工艺制备砷化镓太阳电池，设计了两组线宽(5 μm、7 μm)与三组间距(200 μm、300 μm、400 μm)交叉组合的6种栅线版图，占空比分别为1.23%、1.64%、1.72%、2.28%、2.44%和3.38%，在AM0聚光条件下(聚光倍数159.20~263.87倍)测试了电池的电学性能。实验结果表明：在相同聚光倍数下，填充因子(FF)随占空比增大而提高，短路电流(Isc)总体呈降低趋势，二者呈反向变化关系；电池转换效率存在最优占空比，且最优占空比随聚光倍数提高呈增大趋势。当聚光倍数为206.34倍时，版图A1 (栅线宽度5 μm、间距200 μm、占空比2.44%)测得整体最高转换效率40.72%。本研究为柔性衬底聚光型砷化镓太阳电池的电极结构优化提供了实验依据。

Abstract: To optimize the front electrode structure of flexible concentrator GaAs solar cells, this paper systematically investigates the influence mechanism of grid line duty cycle on cell performance. GaAs solar cells were fabricated by flexible chip lift-off process, and six grid patterns with two line widths (5 μm, 7 μm) and three spacings (200 μm, 300 μm, 400 μm) were designed, with duty cycles of 1.23%, 1.64%, 1.72%, 2.28%, 2.44% and 3.38%, respectively. The electrical properties of the cells were tested under AM0 concentrated illumination with concentration ratios ranging from 159.20 to 263.87 suns. The experimental results show that under the same concentration ratio, the fill factor (FF) increases with the increase of duty cycle, while the short-circuit current (Isc) generally decreases, exhibiting an inverse relationship between the two. The cell conversion efficiency reaches its maximum at an optimal duty cycle, and the optimal duty cycle increases with increasing concentration ratio. When the concentration ratio is 206.34 suns, pattern A1 (line width of 5 μm, spacing of 200 μm, duty cycle of 2.44%) achieves the overall highest conversion efficiency of 40.72%. This study provides experimental guidance for electrode structure optimization of flexible concentrator GaAs solar cells.