Research Progress on Application of Pseudo-halide Anion Engineering in Perovskite Solar Cells

Abstract： Metal halide perovskite solar cells have been able to achieve certified photovoltaic conversion efficiencies of 25. 7%， approaching the maximum certified efficiency of 26.7% for crystalline silicon solar cells.It is well known that the component engineering of the crystal structure of ABX 3 perovskite materials plays a key role in achieving effi• cient and stable devices， especially the component engineering of the X-site halide anion， which has received much at• tention from researchers in recent years.Recently， researchers have carried out several studies on the introduction of pseudo-halide anions as doping components， precursor additives， thin film post-treatment materials， charge transport materials， interfacial passivation， and modifiers for perovskite crystals， and the results demonstrate that pseudo-halide ion modification is an important strategy to improve device efficiency and stability.This review provides a detailed com • parison and summary of the various types of pseudo-halide ions currently available for use in perovskite solar cells and provides an in-depth summary of the mechanisms and nature of their effects on perovskite crystal film morphology， pho• tovoltaic properties， carrier migration properties， and device photovoltaic characteristics and stability.At the same time， this paper also provides an outlook and analysis of the currently unexplored pseudo-halide ions to effectively con• tribute to the enhancement of the photovoltaic properties of perovskite solar cells in future research.