Novel Strategy for High Efficient and Stable Perovskite Solar Cells through Atomic Layer Deposition

The perovskite material has demonstrated conceivable potential as an absorbing material of solar cells. Although the power conversion efficiency of the device based on perovskite has rapidly come to 26%, there are still many factors that affect the further improvement of the photoelectric conversion efficiency. Interface defects are the dominating concern that influence carrier transportation and stability. Here, we report a novel strategy where B₂O₃ is deposited on the fresh perovskite film by atomic layer deposition technology. The organic atmosphere during atomic layer deposition can effectively regulate the crystallization kinetics of perovskites and promote crystal growth. The B₂O₃ adsorbed on the perovskite light-absorption layer can effectively reduce the electropositive defects on the surface of the perovskite, such as uncoordinated Pb²⁺ and I vacancies due to the electron-donating properties of the side O atoms in B₂O₃. Consequently, the power conversion efficiency of the perovskite solar cell after B₂O₃ treatment increases to 21.78% from 18.89%. Simultaneously, B₂O₃ can improve the stability of devices.