Efficient and stable emission of warm-white light from lead-free halide double perovskites

Jiajun Luo, Xiaoming Wang, Shunran Li, Jing Liu, Yueming Guo, Guangda Niu, Li Yao, Yuhao Fu, Liang Gao, Qingshun Dong, Chunyi Zhao, Meiying Leng, Fusheng Ma, Wenxi Liang, Liduo Wang, Shengye Jin, Junbo Han, Lijun Zhang, Joanne Etheridge, Jianbo WangYanfa Yan, Edward H. Sargent, Jiang Tang

Research output: Contribution to journalArticleResearchpeer-review

322 Citations (Scopus)

Abstract

Lighting accounts for one-fifth of global electricity consumption1. Single materials with efficient and stable white-light emission are ideal for lighting applications, but photon emission covering the entire visible spectrum is difficult to achieve using a single material. Metal halide perovskites have outstanding emission properties2,3; however, the best-performing materials of this type contain lead and have unsatisfactory stability. Here we report a lead-free double perovskite that exhibits efficient and stable white-light emission via self-trapped excitons that originate from the Jahn-Teller distortion of the AgCl6 octahedron in the excited state. By alloying sodium cations into Cs2AgInCl6, we break the dark transition (the inversion-symmetry-induced parity-forbidden transition) by manipulating the parity of the wavefunction of the self-trapped exciton and reduce the electronic dimensionality of the semiconductor4. This leads to an increase in photoluminescence efficiency by three orders of magnitude compared to pure Cs2AgInCl6. The optimally alloyed Cs2(Ag0.60Na0.40)InCl6 with 0.04 per cent bismuth doping emits warm-white light with 86 ± 5 per cent quantum efficiency and works for over 1,000 hours. We anticipate that these results will stimulate research on single-emitter-based white-light-emitting phosphors and diodes for next-generation lighting and display technologies.

Original languageEnglish
Pages (from-to)541-545
Number of pages5
JournalNature
Volume563
Issue number7732
DOIs
Publication statusPublished - 1 Nov 2018

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