Stabilizing the MAPbI3 perovksite via the in-situ formed lead sulfide layer for efficient and robust solar cells

Surface passivation via post-treatment with organic reagents is a popular strategy to improve the stability and efficiency of perovskite solar cell. However, organic passivation still suffers from the weak bonding between organic chemicals and perovskite layers. Here we reported a facile inorganic layer passivating method containing strong Pb–S bonding by using ammonium sulfide treatment. A compact PbS_x layer was in-situ formed on the top surface of the perovskite film, which could passivate and protect the perovskite surface to enhance the performance and stability. Our novel inorganic passivation layer strategy demonstrates great potential for the development of high efficiency hybrid and robust perovskite optoelectronics.

Inorganic material passivation of defects toward efficient perovskite solar cells

Surface passivation with organic materials is one of the most effective and popular strategies to improve the stability and efficiency of perovskite solar cells(PSCs). However, the secondary bonding formed between organic molecules and perovskite layers is still not strong enough to protect the perovskite absorber from degradation initialized by oxygen and water attacking at defects. Recently, passivation with inorganic materials has gradually been favored by researchers due to the effectiveness of chemical and mechanical passivation. Lead-containing substances, alkali metal halides, transition elements, oxides,hydrophobic substances, etc. have already been applied to the surface and interfacial passivation of PSCs.These inorganic substances mainly manipulate the nucleation and crystallization process of perovskite absorbers by chemically passivating defects along grain boundaries and surface or forming a mechanically protective layer simultaneously to prevent the penetration of moisture and oxygen, thereby improving the stability and efficiency of the PSCs. Herein, we mainly summarize inorganic passivating materials and their individual passivation principles and methods. Finally, this review offers a personal perspective for future research trends in the development of passivation strategies through inorganic materials.

Inorganic surface passivation strategies of metal halide perovskites

Metal halide perovskites have demonstrated considerable promise across various optoelectronic applications.Surface passivation serves as a pivotal strategy to obtain high‐quality perovskite materials,either in a manner of bulk thin film or nanocrystal,with superior optoelectronic properties and stability.The current research focus in this regard primarily revolves around the use of organic molecules to passivate the surface of perovskites.However,organic passivation molecules always suffer from chemical instability and weak sec-ondary bonding modes,resulting in an unstable surface passivation motif.Inorganic materials,possessing more stable chemical structures and stronger chemical bonding than their organic counterparts,offer the opportunities to construct more robust passivation for the perovskite surfaces.Herein,in this review,we summarized and assessed recent advancements in inorganic sur-face passivation strategies for perovskite materials and devices,ranging from nanocrystals to bulk films.By discussing the mechanisms behind various inorganic passivation strategies,we aim to offer mechanistic insights and guidelines for future developments of more targeted surface passivation ap-proaches tailored for perovskite materials and devices.