Dark-blue mirror-like perovskite dense films for efficient organic–inorganic hybrid solar cells

Abstract

To date, numerous approaches have been developed for fabricating high quality organometal halide perovskite thin films, however, perovskite films obtained by such methods reveal a brown or dark-brown color, which might restrain their light absorption ability. Here we report a route to synthesize dark-blue mirror-like perovskite dense films via a two-step spin-coating process assisted by treatment of nonpolar solvent scouring. Photovoltaic cells based on such dark-blue films demonstrate a high short-circuit current density (J_sc) of ∼23 mA cm⁻² and a power conversion efficiency (PCE) of 16.1%. Our method would provide a new candidate method for the fabrication of perovskite solar cells with high performance.