Flexible and lightweight Cu(In,Ga)Se₂ (CIGS) thin-film solar cells are promising for versatile applications, but there is limited understanding of stress-induced changes. In this study, the charge carrier generation and trapping behavior under mechanical stress was investigated using flexible CIGS thin-film solar cells with various alkali treatments. Surface current at the CIGS surface decreased by convex bending, which occurs less with the incorporation of alkali metals. The formation energy of the carrier generating defects increased in convex bending environments clarifying the degradation of the surface current. Moreover, alkali-related defects had lower formation energy than the intrinsic acceptors, mitigating current degradation in mechanical stress condition. The altered defect energy levels were attributed to the deformation of the crystal structure under bending states. This study provides insights into the mitigating of strain-induced charge degradation for enhancing the performance and robustness of flexible CIGS photovoltaic devices.

柔性轻质 Cu(In,Ga)Se ₂ (CIGS) 薄膜太阳能电池有望实现多种应用，但对应力引起的变化的了解有限。在本研究中，使用经过各种碱处理的柔性 CIGS 薄膜太阳能电池研究了机械应力下载流子的产生和捕获行为。 CIGS 表面的表面电流因凸弯曲而降低，这种情况随着碱金属的加入而减少。在凸弯曲环境中，产生缺陷的载流子的形成能增加，这表明表面电流的退化。此外，与碱相关的缺陷的形成能比本征受体低，从而减轻了机械应力条件下的电流退化。缺陷能级的改变归因于弯曲状态下晶体结构的变形。这项研究提供了关于减轻应变引起的电荷退化的见解，以提高柔性 CIGS 光伏器件的性能和鲁棒性。