Addition of extrinsic metal ions is shown to induce n-type doping of polycrystalline perovskite films. The resulting polycrystalline films exhibit doping at the film surface and along grain boundaries. Addition of optimized amounts of metal ions lead to formation of p-n junctions within individual perovskite grains. The resulting lateral homojunction structure increases charge carrier lifetimes, which leads to improved power conversion efficiencies for solar cell devices comprised of these metal-doped perovskite films.
· Metal ions dope surface of perovskite films to n-type metallic state
· Devices comprised of metal-doped perovskite films demonstrate efficiencies up to 20.8%