Tuning CH 3 NH 3 Pb(I 1-x Br x ) 3 Perovskite Oxygen Stability in Thin Films and Solar Cells - Pont, S; Bryant, D; Lin, CH; Aristidou, N; Wheeler, S; Ma, X; Godin, R; Haque, S; Durrant, JR (Journal of Materials Chemistry A, 2017)