Room‐Temperature Ion‐Exchange‐Mediated Self‐Assembly toward Formamidinium Perovskite Nanoplates with Finely Tunable, Ultrapure Green Emissions for Achieving Rec. 2020 Displays. (12th March 2018)

• Record Type: Journal Article
• Authors: Yu, Dejian; Cao, Fei; Gao, Yujie; Xiong, Yunhai; Zeng, Haibo
• Is Part Of: Advanced functional materials. Volume 28:Number 19(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-03-12
• Subjects: backlit displays -- halide perovskites -- ion‐exchange -- self‐assembly -- ultrapure green backlight; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201800248
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Delicate engineering of chromaticity is required to faithfully reproduce colors in a backlit display, this is extremely difficult for green downconverters because the human eye is highly sensitive to green colors. The central challenge is to achieve finely tunable green emissions in the narrow range of 525–535 nm while keeping the full width at half maximum (FWHM) <25 nm at the same time. Here, a room‐temperature ion‐exchange‐mediated self‐assembly strategy for preparing FAPbBr3 (FA = CH(NH2 )2 + ) nanoplates (NPs) to fulfill this goal is introduced. 2D layered OA2 PbBr4 (OA is octadecylamine) NPs are first synthesized by spontaneous reprecipitation, and are then transformed into FAPbBr3 NPs through a OA + ‐to‐FA + exchange induced self‐assembly of HP monolayers. A c ‐axis contraction in this process makes a relative large thickness variation in OA2 PbBr4 NPs, which can be realized by simply varying the precursor concentration, only result in a small thickness change in subsequent FAPbBr3 NPs, thereby enabling finely tunable emissions in the range of 525–535 nm along with FWHM <25 nm and a quantum yield up to 85%. As a downconverter, the FAPbBr3 NPs realize an ultrapure green backlight that covers ≈95% Rec. 2020 standard in the CIE 1931 color space. Abstract : A room‐temperature ion‐exchange‐mediated self‐assembly strategy is developed to prepare FAPbBr3 nanoplates. This strategy enables finely tunable, ultrapure green emissions in the highly desirable narrow range of 525–535 nm along with narrow linewidths and high photoluminescence quantum yields, therefore enabling the "greenest" backlight for displays.