Flexible Si/PEDOT:PSS hybrid solar cells

Abstract

Si hybrid solar cells have attracted tremendous research attention in recent years because of their low production costs and high performance. However, flexible Si hybrid solar cells have rarely been reported owing to the difficulty of fabricating single-crystalline Si with good flexibility. In this study, we fabricated flexible Si/PEDOT:PSS hybrid solar cells with micro-pyramid-structured Si light absorbers using a facile approach. Compared with planar flexible hybrid solar cells with a power-conversion efficiency of 4%, solar cells with micro-pyramid-structured Si light absorbers have a higher efficiency of 6.3%. External quantum efficiency and electrochemical impedance spectroscopy measurements revealed that the solar cells with micro-pyramid-structured Si light absorbers exhibited a pronounced light-harvesting enhancement in the spectra region of 400–1,000 nm and had a smaller series resistance and larger recombination resistance compared with the planar cells, yielding a higher efficiency. Additionally, in mechanical-bending tests, the flexible solar cells with micro-pyramid-structured Si light absorbers exhibited an excellent performance stability after bending for 600 cycles. Our findings lay the foundation for the real-world applications of flexible Si/PEDOT:PSS hybrid solar cells in next-generation portable electronics.