A photovoltaic device, comprises (1) a first conductive layer, (2) an optional blocking layer, on the first conductive layer, (3) a semiconductor layer, on the first conductive layer, (4) a light-harvesting material, on the semiconductor layer, (5) a hole transport material, on the light-harvesting material, and (6) a second conductive layer, on the hole transport material. The light-harvesting material comprises a perovskite absorber, and the second conductive layer comprises nickel. The semiconductor layer may comprise TiO2 nanowires. The light-harvesting material may comprise a perovskite absorber containing a pseudohalogen.