Toward lossless photovoltaic efficiency of Laser-shaped flexible Cu(In,Ga)Se2 solar cells on stainless steel substrates

Abstract

Flexible Cu(In,Ga)Se2 (CIGS) solar cells on metal substrates are susceptible to thermal effects during laser shaping, resulting in their failure. In this study, a two-step scribing–cutting approach for shaping CIGS cells on stainless steel foil substrates was developed. Electrical–thermal dual isolations were performed by laser scribing to guard against damage to the CIGS cells during the laser shaping process. The efficiency loss ratio after an ultraviolet nanosecond laser shaping decreased from an average of 80% for the one-step method to an average of < 10% for the two-step method. The efficiency loss could be further decreased with a larger cell area of > 1 cm2, which is closer to lossless laser shaping. This method was also demonstrated successfully on curved-shaped cells. This work opens up the prospect of using laser shaping in the mass manufacture of flexible CIGS solar cells on metal substrates.