Laser‐assisted Nano‐texturing for Flexible Ultrathin Crystalline Si Solar Cells

Ultrathin (UT) crystalline Si wafers, which are more flexible than conventional ones, can apply to curved surfaces, enabling a wide range of applications such as building‐integrated photovoltaics, vehicle‐integrated and wearable devices. Thinner wafers require effective light trapping; thus, surface texturing in microscale is common approach compensate for the reduced thickness by enhancing pathlength. Microscale textures, however, deteriorate mechanical flexibility due stress concentration valley microtextures. In this study, laser‐assisted nanotexturing process proposed enhanced UT solar cells with 50 μm while maintaining light‐trapping performances. A nanolens array used focus laser onto inducing formation nanoparticle etch masks nanopyramid an alkaline solution. The origin nanotextured discussed micromechanics simulation study. Herein, technique applied Si‐based passivated emitter rear 26 mm critical bending radius demonstrated. Also, it shown that wafer provides higher efficiency 18.68%, whereas microtextured one exhibits 18.10%.