Monolithic perovskite/perovskite/silicon triple-junction solar cells with cation double displacement enabled 2.0 eV perovskites

• DOI: 10.1016/j.joule.2023.11.018
• Publication Date: 2023-12-28T15:33:26Z
• Authors: Fuzong Xu; Erkan Aydin; Jiang Liu; Esma Ugur; George T. Harrison; Lujia Xu; Badri Vishal; Bumin K. Yildirim; Mingcong Wang; Roshan Ali; Anand S. Subbiah; Aren Yazmaciyan; Shynggys Zhumagali; Wenbo Yan; Yajun Gao; Zhaoning Song; Chongwen Li; Sheng Fu; Bin Chen; Atteq ur Rehman; Maxime Babics; Arsalan Razzaq; Michele De Bastiani; Thomas G. Allen; Udo Schwingenschlögl; Yanfa Yan; Frédéric Laquai; Edward H. Sargent; Stefaan De Wolf
• Keywords: 669; 02 engineering and technology; 0210 nano-technology

Perovskite/perovskite/silicon triple-junction solar cells hold promise for surpassing their two-junction counterparts in performance. Achieving this requires monolithic integration of a 2.0 eV bandgap perovskite subcell, characterized by a high bromide:iodide ratio (>7:3), and with low-temperature processability and high optoelectronic quality. However, light-induced phase segregation in such perovskites remains a challenge. To address this, we propose modifying the wide-band-gap perovskite with potassium thiocyanate (KSCN) and methylammonium iodide (MAI) co-additives, where SCN increases the perovskite grain size, reducing the grain boundary defect density; K+ immobilizes the halide, preventing the formation of halide vacancies; and MA+ eliminates the residual light-destabilizing SCN in the perovskite films via double displacement reactions. Our co-additive strategy enables enhanced photostability, whereas individual usage of MAI and KSCN would result in adverse effects. Triple-junction tandem solar cells, incorporating co-additive-modified 2.0 eV perovskites as top cell absorbers, reach a 3.04 V open-circuit voltage and a PCE of 26.4% over a 1 cm2 area. ; This work was supported by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under award no: OSR-CARF URF/1/3079-33-01, KAUST OSR-CRG 400 RF/1/3383, and KAUST OSR-CRG2018-3737. The authors thank Shruti Sarwade for the technical support during the bottom cell development and Anil Pininti for the laser scribing of the bottom cells.