Inorganic CsPbBr3 Perovskite Nanocrystals as Interfacial Ion Reservoirs to Stabilize FAPbI3 Perovskite for Efficient Photovoltaics. Issue 16 (13th March 2022)

• Record Type: Journal Article
• Authors: Chen, Yuetian; Wei, Ning; Miao, Yanfeng; Chen, Haoran; Ren, Meng; Liu, Xiaomin; Zhao, Yixin
• Is Part Of: Advanced energy materials. Volume 12:Issue 16(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-13
• Subjects: interfacial modification -- ion exchange -- ion reservoirs -- perovskite nanocrystals -- perovskite solar cells; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202200203
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Bulk lead halide perovskite films with unique optoelectronic properties and facile low‐cost processing methods are promising for various optoelectronic applications including photovoltaics. Solution‐processed colloidal inorganic perovskite nanocrystals with higher crystallinity hold good potential for devices with better stability and optoelectronic properties. To address phase stability and defect passivation issues in black phase FAPbI3 perovskite, all‐inorganic perovskite CsPbBr3 nanocrystals (CPB NCs) are adapted as an effective modifier to form CPB NC‐treated FAPbI3 perovskite films (noted as CPB NC‐FAPbI3 ). It is identified in this study that, the incorporated CsPbBr3 NCs not only act as surface additives for the bulk perovskite films, but can also serve as ion reservoirs to supply both cation and halide exchanges at the interface. This two‐way ion exchange in CPB NC‐FAPbI3 samples leads to the formation of a compositional gradient as FA1− x Cs x PbI3− y Br y layers on the bulk perovskite film surface with vertically varied x and y values. Defects at interfaces and grain boundaries are therefore effectively passivated, leading to improved stability and charge carrier dynamics. As a result, the CPB NC‐FAPbI3 perovskite based solar cells exhibit overall enhancements in device efficiency and operational stability. Abstract : Highly stable inorganic perovskite CsPbBr3 nanocrystals are adapted to modify bulk FAPbI3 perovskite films. An ion reservoir is achieved to support a simultaneous two‐way ion exchange at the interface, which can supply and store both cations and halides. Defects are therefore effectively passivated, leading to improved charge carrier dynamics and overall enhancement of efficiency and stability of the fabricated photovoltaics.