Flexible and Cd free CIGS solar cell yielding 13.37% efficiency producing by non-vacuum process

CIGS solar cell has yielded the high efficiency beyond 20% on glass substrate [1], but some drawbacks such as heavy, not portable, toxic and costly need to be met for future manufacture. In this study, ZnS(O,OH)/CIGSeS solar cells were fabricated on flexible stainless steel substrate by low-cost nano-particle printing process. The flexible and non-toxic CIGSeS solar cell shows the efficiency as high as 13.37% without anti-reflection layer. The high efficiency was attributed to good thin film quality in absorption layer and buffer layer. Besides, the ZnS(O,OH) buffer layer with thickness only 15 nm shows good coverage, which enhances photocurrent and leads to high efficiency. Moreover, the CIGSeS solar cells were placed to dark room for 3 days to test light soaking effects, the results show that only 0.14% efficiency decay was measured. The results implies that the non-toxic and flexible CIGSeS solar cells prepared by nanoparticle printing process shows high potential for portable power source and building integrated photovoltaic system.