Modified photoelectric properties of CH3NH3PbI3 via surface passivation induced by argon ions bombardment

Highlights: • Ions bombardment induces PbI₂ layer at the surface of perovskite films. • PbI₂ layer passivates defect to enhance photoelectric properties of perovskite films. • The random distribution of PbI₂ in films is avoided. -- Abstract: Many investigations have revealed that PbI₂ plays a passivated role to reduce the charge recombination in the perovskite films. However, due to the random distribution of PbI₂ in perovskite films, the passivation effect is blanketed to some extent. In this work, we use the argon ions bombardment to deliberately induce the PbI₂ layer at the surface of perovskite films and investigate the photoelectric performance of samples. It is found that the PbI₂ layer at the surface can passivate the defects effectively, leading to an improvement of the photoconduction by an order of magnitude as well as the responsivity by >4 times under the irradiation of 405 nm light. The bombardment provides an effective method for perovskite surface passivation and optimizing the performances of perovskite-based photoelectric devices.