High efficiency triple-junction GaAs flexible thin film solar cell
Wei Jiang, Juncheng Li, Hongqing Wu, Zhenlong Wu, Sheng He, Xiaoya Han, Shilei Du, Kaixuan Chen, Shuangxiang Zhang
Xiamen Changelight Co., LTD, Xiamen, China

In recent years, it has become a research hotspot to make high power conversion efficiency GaAs flexible solar cell by removing the GaAs epitaxial layer from the substrate and bonding it on the flexible material. However, due to the presence of voids in the interface of the bonding layer, a seriously negative impact is induced to the reliability of the solar cell chip especially in the vacuum environment. Therefore, we employ an In/Au bilayer structure as a bonding layer, and simultaneously optimize the bonding temperature and pressure. Scanning electron microscopy results show that the interface of the bonding layer exhibits a perfect fusion state which avoids the formation of voids. After the chip process, 12cm2 large triple-junctions GaAs flexible solar cells with high efficiency are fabricated, and the conversion efficiency reached 30.75% under air mass 0 and no performance degradation was noted after 60 thermal cycles.

Area: Sub-Area 3.7: Mobile Solar Power/ High Efficiency Flexible lightweight PV for UAVs (Joint Areas 3, 7 and 8)