Oxidative Passivation of FAPbI₃ via Femtosecond Laser for Enhanced Photoluminescence and Photoresponse Performance

The presence of uncoordinated Pb atoms in perovskite materials, acting as non-radiative recombination centers, significantly degrades the performance of perovskite-based photoelectronic devices. Addressing this issue by passivating these deep energy level defects is essential for enhancing device performance. By now, the passivation methods are largely proposed by chemical additive engineering methods, which involve the oxidation of Pb through chemical additives. However, chemical passivation methods are often plagued by issues such as prolonged processing times, uncontrollable passivation regions uncontrollable, and environmental contamination. Here, a novel femtosecond laser oxidative passivation (FsLOP) technique for FAPbI₃ is proposed, evidenced by X-ray photoelectron spectroscopy (XPS) revealing the formation of Pb─O bonds. The role of peroxide anions in oxidation passivation is highlighted as pivotal. The oxidative passivation effect is further corroborated by a four-fold increase in photoluminescence (PL) intensity and an exceptional improvement in photoresponse performance, achieving a detectivity of 6.77 × 10¹² Jones. This work provides a deeper insight into the interaction between femtosecond lasers and perovskite materials, proposing an efficient, precisely controlled, and environmentally friendly way to improve the performance of perovskite photoelectronic devices.