Shen, X.; Gallant, B.M.; Holzhey, P.; Smith, J.A.; Elmestekawy, K.A.; Yuan, Z.; Rathnayake, P.V.G.M.; Bernardi, S.; Dasgupta, A.; Kasparavicius, E.; Malinauskas, T.; Caprioglio, P.; Shargaieva, O.; Lin, Y.H.; McCarthy, M.M.; Unger, E.; Getautis, V.; Widmer-Cooper, A.; Herz, L.M.; Snaith, H.J.: Chloride-Based Additive Engineering for Efficient and Stable Wide-Bandgap Perovskite Solar Cells. Advanced Materials 35 (2023), p. 2211742/1-11
10.1002/adma.202211742
Open Access Version
Abstract:
Metal halide perovskite based tandem solar cells are promising to achieve power conversion efficiency beyond the theoretical limit of their single-junction counterparts. However, overcoming the significant open-circuit voltage deficit present in wide-bandgap perovskite solar cells remains a major hurdle for realizing efficient and stable perovskite tandem cells. Here, a holistic approach to overcoming challenges in 1.8 eV perovskite solar cells is reported by engineering the perovskite crystallization pathway by means of chloride additives. In conjunction with employing a self-assembled monolayer as the hole-transport layer, an open-circuit voltage of 1.25 V and a power conversion efficiency of 17.0% are achieved. The key role of methylammonium chloride addition is elucidated in facilitating the growth of a chloride-rich intermediate phase that directs crystallization of the desired cubic perovskite phase and induces more effective halide homogenization. The as-formed 1.8 eV perovskite demonstrates suppressed halide segregation and improved optoelectronic properties.