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Highly Efficient and Tunable Emission of Lead‐Free Manganese Halides toward White Light‐Emitting Diode and X‐Ray Scintillation Applications
Author(s) -
Jiang Tingming,
Ma Wenbo,
Zhang Hao,
Tian Yue,
Lin Gang,
Xiao Wenge,
Yu Xue,
Qiu Jianbei,
Xu Xuhui,
Michael Yang Yang,
Ju Dianxing
Publication year - 2021
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202009973
Subject(s) - materials science , photoluminescence , halide , manganese , luminescence , quantum yield , light emitting diode , optoelectronics , scintillation , analytical chemistry (journal) , optics , fluorescence , inorganic chemistry , chemistry , physics , metallurgy , chromatography , detector
Environmental friendly metal halides have become emerging candidates as energy downconverting emitters for lighting and X‐ray imaging applications. Herein, luminescent single crystals of tetramethylammonium manganese chloride (C 4 H 12 NMnCl 3 ) and tetraethylammonium bromide ((C 8 H 20 N) 2 MnBr 4 ) are synthesized via a facile room‐temperature evaporation method. C 4 H 12 NMnCl 3 and (C 8 H 20 N) 2 MnBr 4 with octahedrally and tetrahedrally coordinated Mn 2+ have correspondingly exhibited red and green emission peaking at 635 and 515 nm both originating from 4 T 1 – 6 A 1 transition of Mn 2+ with high photoluminescence quantum yield (PLQY) of 91.8% and 85.1% benefiting from their specific crystal structures. Thanks to their strong photoexcitation under blue light, high PLQY, tunable emission spectra, good environmental stability, the white light‐emitting diode based on blending of C 4 H 12 NMnCl 3 and (C 8 H 20 N) 2 MnBr 4 delivers an outstanding luminous efficacy of 96 lm W −1 , approaching commercial level, and shows no obvious photoluminescence intensity degradation after 3000 h under operation. In addition, manganese halides also demonstrate interesting characteristics under X‐ray excitation, C 4 H 12 NMnCl 3 and (C 8 H 20 N) 2 MnBr 4 exhibit steady‐state X‐ray light yields of 50 500 and 24 400 photons MeV −1 , low detectable limits of 36.9 and 24.2 nGy air s −1 , good radiation hardness, and X‐ray imaging demonstration with high‐resolution of 5 lp mm −1 . This work presents a new avenue for luminescent Mn‐based metal halides toward multifunctional light‐emitting applications.