Evidence for surface defect passivation as the origin of the remarkable photostability of unencapsulated perovskite solar cells employing aminovaleric acid as a processing additive - Lin, C-T; Rossi, F; Kim, J; Baker, J; Ngiam, J; Xu, S; Pont, S; Aristidou, N; Haque, S; Watson, T; McLachlan, M; Durrant, J (Journal of Materials Chemistry A, 2019)