Cerium oxide as an efficient electron extraction layer for p–i–n structured perovskite solar cells

Abstract

Cerium oxide, solution processed at a low temperature (∼100 °C), was successfully employed as an electron extraction layer on top of a perovskite. The CeO_x layer shows good charge selectivity and increases light reflection from an Ag electrode. Besides this, the CeO_x layer not only protects the perovskite from water, but also acts as a dense diffusion barrier to prevent the corrosion of the metal electrode.