A generic interface to reduce the efficiency-stability-cost gap of perovskite solar cells by Hou, Y, Du, X, Scheiner, S, McMeekin, DP, Wang, Z, Li, N, Killian, MS, Chen, H, Richter, M, Levchuk, I, Schrenker, N, Spiecker, E, Stubhan, T, Luechinger, NA, Hirsch, A, Schmuki, P, Steinrück, H-P, Fink, RH, Halik, M, Snaith, HJ, Brabec, CJ