Structurally Reinforced All‐Inorganic CsPbI2Br Perovskite by Nonionic Polymer via Coordination and Hydrogen Bonds. Issue 9 (11th June 2020)

• Record Type: Journal Article
• Authors: Peng, Huirong; Cai, Molang; Zhou, Jiyu; Yang, Yi; Ding, Xihong; Tao, Ye; Wu, Gao; Liu, Xuepeng; Pan, Jia Hong; Dai, Songyuan
• Is Part Of: Solar RRL. Volume 4:Issue 9(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-06-11
• Subjects: all-inorganic perovskites -- coordination -- humidity stability -- hydrogen bonds -- polyethyleneimine; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202000216
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : The all‐inorganic CsPbI2 Br perovskite with superior thermal durability faces challenges of low‐phase stability and high moisture sensitivity. Herein, a nonionic additive of polyethyleneimine (PEI) with multiple amino groups is introduced to form hydrogen bond with I − /Br − ions and coordinate with Pb 2+ /Cs + ions simultaneously. The strong interplay between PEI and CsPbI2 Br achieves a well‐controlled grain size, reduced defects, and reinforced phase structure of CsPbI2 Br film, which boosts the power conversion efficiency (PCE) of perovskite solar cells to 15.48%. The hydrophobic long alkyl chain of PEI greatly improves the humidity resistance, retaining 81.9% of initial PCE of zjr unsealed device under 20 ± 5% relative humidity (RH) for 500 h. Remarkably, a PCE of 13.37% is achieved by the device based on CsPbI2 Br–PEI film processed under ambient condition (≈22% RH, ≈25 °C). Abstract : The nonionic polymer with multiple amino groups is introduced to passivate both metal‐ and halide‐induced defects of all‐inorganic CsPbI2 Br perovskite by coordination and hydrogen bonds, simultaneously. Consequently, a well‐controlled grain size, reduced defects, and reinforced phase structure of CsPbI2 Br film are achieved, which boosts the efficiency of perovskite solar cells up to 15.48% with excellent humidity stability.