Chloride-based additive engineering for efficient and stable wide-bandgap perovskite solar cells by Shen, X, Gallant, BM, Holzhey, P, Smith, JA, Elmestekawy, KA, Yuan, Z, Rathnayake, PVGM, Bernardi, S, Dasgupta, A, Kasparavicius, E, Malinauskas, T, Caprioglio, P, Shargaieva, O, Lin, Y-H, McCarthy, MM, Unger, E, Getautis, V, Widmer-Cooper, A, Herz, LM, Snaith, HJ