Free-standing ultrathin silicon wafers and solar cells through edges reinforcement

• Published in: Nature communications Vol. 15; no. 1; p. 3843
• Main Authors: Wu, Taojian, Liu, Zhaolang, Lin, Hao, Gao, Pingqi, Shen, Wenzhong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07.05.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 639/4077/909/4101/4096/946; 639/766/119/1000; Brittleness; Efficiency; Fabrication; Humanities and Social Sciences; Lightweight; Manufacturing industry; Market potential; Mechanical properties; multidisciplinary; Photovoltaic cells; Photovoltaics; Rigidity; Science; Science (multidisciplinary); Silicon; Silicon wafers; Solar cells; Wafers; Weight reduction
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-48290-5

Crystalline silicon solar cells with regular rigidity characteristics dominate the photovoltaic market, while lightweight and flexible thin crystalline silicon solar cells with significant market potential have not yet been widely developed. This is mainly caused by the brittleness of silicon wafers and the lack of a solution that can well address the high breakage rate during thin solar cells fabrication. Here, we present a thin silicon with reinforced ring (TSRR) structure, which is successfully used to prepare free-standing 4.7-μm 4-inch silicon wafers. Experiments and simulations of mechanical properties for both TSRR and conventional thin silicon structures confirm the supporting role of reinforced ring, which can share stress throughout the solar cell preparation and thus suppressing breakage rate. Furthermore, with the help of TSRR structure, an efficiency of 20.33% (certified 20.05%) is achieved on 28-μm silicon solar cell with a breakage rate of ~0%. Combining the simulations of optoelectrical properties for TSRR solar cell, the results indicate high efficiency can be realized by TSRR structure with a suitable width of the ring. Finally, we prepare 50 ~ 60-μm textured 182 × 182 mm 2 TSRR wafers and perform key manufacturing processes, confirming the industrial compatibility of the TSRR method. Lightweight and flexible thin crystalline silicon solar cells have huge market potential but remain relatively unexplored. Here, authors present a thin silicon structure with reinforced ring to prepare free-standing 4.7-μm 4-inch silicon wafers, achieving efficiency of 20.33% for 28-μm solar cells.