Comprehensive defect suppression in perovskite nanocrystals for high-efficiency light-emitting diodes

Young Hoon Kim, Sungjin Kim, Arvin Kakekhani, Jinwoo Park, Jaehyeok Park, Yong Hee Lee, Hengxing Xu, Satyawan Nagane, Robert B. Wexler, Dong Hyeok Kim, Seung Hyeon Jo, Laura Martínez-Sarti, Peng Tan, Aditya Sadhanala, Gyeong Su Park, Young Woon Kim, Bin Hu, Henk J. Bolink, Seunghyup Yoo, Richard H. FriendAndrew M. Rappe, Tae Woo Lee

Research output: Contribution to journalArticlepeer-review

99 Scopus citations

Abstract

Electroluminescence efficiencies of metal halide perovskite nanocrystals (PNCs) are limited by a lack of material strategies that can both suppress the formation of defects and enhance the charge carrier confinement. Here we report a one-dopant alloying strategy that generates smaller, monodisperse colloidal particles (confining electrons and holes, and boosting radiative recombination) with fewer surface defects (reducing non-radiative recombination). Doping of guanidinium into formamidinium lead bromide PNCs yields limited bulk solubility while creating an entropy-stabilized phase in the PNCs and leading to smaller PNCs with more carrier confinement. The extra guanidinium segregates to the surface and stabilizes the undercoordinated sites. Furthermore, a surface-stabilizing 1,3,5-tris(bromomethyl)-2,4,6-triethylbenzene was applied as a bromide vacancy healing agent. The result is highly efficient PNC-based light-emitting diodes that have current efficiency of 108 cd A−1 (external quantum efficiency of 23.4%), which rises to 205 cd A−1 (external quantum efficiency of 45.5%) with a hemispherical lens.

Original languageEnglish
Pages (from-to)148-155
Number of pages8
JournalNature Photonics
Volume15
Issue number2
DOIs
StatePublished - 2021 Feb
Externally publishedYes

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