The impact of cation and anion pairing in ionic salts on surface defect passivation in cesium lead bromide nanocrystals. Issue 3 (21st December 2020)

• Record Type: Journal Article
• Authors: Yoon, Lucy U.; Alpert, Matthew R.; Luo, Hongxi; Schapowal, Michael I.; Holmgren, Eric N.; Geise, Geoffrey M.; Paolucci, Christopher; Choi, Joshua J.
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 3(2021)
• Page Start: 991
• Page End: 999
• Publication Date: 2020-12-21
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc04257a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Binding strength between cation and anion in a ligand has a major impact on their charge trap passivation efficacy. Abstract : Imperfect passivation of surface charge traps on metal halide perovskite (MHP) nanocrystals remains a key obstacle to achieving higher performance in optoelectronic devices. Due to the strong ionic nature of MHPs, ionic salts have been identified as effective surface charge trap passivating ligands. In this study, based on photoluminescence quantum yield (PLQY) and time-resolved photoluminescence (TRPL) measurements on cesium lead bromide nanocrystals (CsPbBr3 NCs), we find that the pairing between cation and anion of an ionic salt results in a significant impact on trap passivation. Using density of functional theory (DFT) calculations, we identify the binding interaction between the cation and anion of the ionic pair to be a major factor in determining the trap passviation efficacy.