作者
Fuzong Xu,Erkan Aydın,Jiang Liu,Esma Ugur,George T. Harrison,Lujia Xu,Badri Vishal,Bumın K. Yildırım,Mingcong Wang,Roshan Ali,Anand S. Subbiah,Aren Yazmaciyan,Shynggys Zhumagali,Wenbo Yan,Yajun Gao,Zhaoning Song,Chongwen Li,Sheng-Quan 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
摘要
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 band-gap 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.