Phase rearrangement for minimal exciton loss in a quasi-2D perovskite toward efficient deep-blue LEDs via halide post-treatment. Issue 47 (22nd November 2022)

• Record Type: Journal Article
• Authors: Shin, Yun Seop; Yoon, Yung Jin; Adhikari, Aniruddha; Cho, Hye Won; Song, Taehee; Park, Chan Beom; Son, Jung Geon; Kim, Gi-Hwan; Kwon, Oh-Hoon; Kim, Jin Young
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 47(2022)
• Page Start: 17945
• Page End: 17953
• Publication Date: 2022-11-22
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc04025e
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : With a facile halide and phase modulating approach, deep-blue emissive quasi-2D perovskite films involving fewer intervening 2D phases are realized, for efficient delivery of excitons to light-emitting phases via streamlined energy transfer. Abstract : Electroluminescence efficiencies of deep-blue quasi-two-dimensional (quasi-2D) perovskites are limited by a lack of post-treatment strategies that can both construct an ideal energy-transfer tunnel structure minimizing the exciton losses and passivate chlorine vacancies. Herein, multi-functional halide post-exchange is demonstrated for fabricating efficient deep-blue quasi-2D perovskite light-emitting diodes (PeLEDs). This post-treatment suppresses detrimental chlorine vacancies in the perovskite lattice, resulting in an efficient deep-blue perovskite emitter. Synergistically, the spontaneous phase rearrangement occurs via merging between neighboring low- n phases to higher- n phases. The narrowed 2D phase distribution enhances excitonic-energy transfer to the target bulk phase with fewer energy transfer steps, each of which is accompanied by adverse energy loss by exciton dissociation. Efficient deep-blue PeLEDs with a maximum external quantum efficiency of 4.97% are realized, emitting at 470 nm. Device lifetimes are also elongated as a synergetic benefit. This work provides an effective approach as a step closer to designing high-performance deep-blue PeLEDs for practical applications.