Lee, Hyeon-Seung Choi, Jae Myeong Jung, Beomsic Kim, Joonkon Song, Jonghan Jeong, Doo Seok Park, Jong-Keuk Kim, Won Mok Lee, Doh-Kwon Lee, Taek Sung Lee, Wook Seong Lee, Kyeong-Seok Ju, Byeong-Kwon Kim, Inho 2024-01-19T18:32:18Z 2024-01-19T18:32:18Z 2021-09-04 2019-12-24 2045-2322 https://pubs.kist.re.kr/handle/201004/119184 We report high efficiency cell processing technologies for the ultra-thin Si solar cells based on crystalline Si thin foils (below a 50 mu m thickness) produced by the proton implant exfoliation (PIE) technique. Shallow textures of submicrometer scale is essential for effective light trapping in crystalline Si thin foil based solar cells. In this study, we report the fabrication process of random Si nanohole arrays of ellipsoids by a facile way using low melting point metal nanoparticles of indium which were vacuum-deposited and dewetted spontaneously at room temperature. Combination of dry and wet etch processes with indium nanoparticles as etch masks enables the fabrication of random Si nanohole arrays of an ellipsoidal shape. The optimized etching processes led to effective light trapping nanostructures comparable to conventional micro-pyramids. We also developed the laser fired contact (LFC) process especially suitable for crystalline Si thin foil based PERC solar cells. The laser processing parameters were optimized to obtain a shallow LFC contact in conjunction with a low contact resistance. Lastly, we applied the random Si nanohole arrays and the LFC process to the crystalline Si thin foils (a 48 mu m thickness) produced by the PIE technique and achieved the best efficiency of 17.1% while the planar PERC solar cell without the Si nanohole arrays exhibit 15.6%. Also, we demonstrate the ultra-thin wafer is bendable to have a 16 mm critical bending radius. English NATURE PUBLISHING GROUP LIGHT MANAGEMENT LAYER-TRANSFER SILICON NANOSTRUCTURES PROGRESS WAFERS Random nanohole arrays and its application to crystalline Si thin foils produced by proton induced exfoliation for solar cells Article 10.1038/s41598-019-56210-7 1 SCIENTIFIC REPORTS, v.9 SCIENTIFIC REPORTS 9 scie scopus 000508915300007 2-s2.0-85077143827 Multidisciplinary Sciences Science & Technology - Other Topics Article LIGHT MANAGEMENT LAYER-TRANSFER SILICON NANOSTRUCTURES PROGRESS WAFERS Kerfless wafering Silicon nanostructure Random nanohole arrays PERC Ultrathin Silicon