Effects of mechanical strain on the performance of amorphous silicon triple-junction solar cells

Amorphous silicon triple-junction solar cells were tested in tension and compression. The production cells had the structure: stainless steel (125 /spl mu/m)/Al/ZnO/n/sub 1/i/sub 1/p/sub 1/n/sub 2/i/sub 2/p/sub 2/n/sub 3/i/sub 3/p/sub 3//ITO/grid, where i/sub 1/ and i/sub 2/ are a-SiGe:H and i/sub 3/ is a-Si:H. We bent the solar cells to strains as high as 2%. The I-V characteristics of the cells were tested before, during and after bending. We found that there was little deterioration in cell performance under compression up to 1.7% strain, which is the physical limit of our experiment. In tension, some cell characteristics began to degrade at strains of 0.75%. Plastic deformation was observed at strains of 0.2% and higher.