Structural Impact and Optical Optimization in Stretchable Thin Film Flexible Solar Cells

Surface texturing in bulk silicon solar cells leads to record high efficiencies due to the reduced reflection and increased optical path lengths. High efficiency thin film solar cells are also feasible with a combination of ultra-thin absorption layer and textured structural design. Based on the rigorous coupled-wave analysis, we report here the structural impact and optical optimization of thin film flexible solar cells with wavy and V-shaped stretchable thin film designs. Compared to the flat thin film solar cells, the effective optical path lengths increases by five-fold at longer wavelength, and the efficiency doubles in wavy and V-shaped thin film solar cells with the same absorption layer thicknesses.