Premium
Efficient Thermally Activated Delayed Fluorescence from All‐Inorganic Cesium Zirconium Halide Perovskite Nanocrystals
Author(s) -
Liu Siping,
Yang Bin,
Chen Junsheng,
Wei Donghui,
Zheng Daoyuan,
Kong Qingkun,
Deng Weiqiao,
Han Keli
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202009101
Subject(s) - halide , photoluminescence , perovskite (structure) , nanocrystal , photochemistry , phosphor , inorganic chemistry , excited state , chemistry , fluorescence , zirconium , materials science , nanotechnology , crystallography , optoelectronics , physics , quantum mechanics , nuclear physics
Thermally activated delayed fluorescence (TADF) is generally observed in solid‐state organic molecules or metal‐organic complexes. However, TADF in all‐inorganic colloidal nanocrystals (NCs) is rare. Herein, we report the first colloidal synthesis of an air‐stable all‐inorganic lead‐free Cs 2 ZrCl 6 perovskite NCs. The Cs 2 ZrCl 6 NCs exhibit long‐lived triplet excited state (138.2 μs), and feature high photoluminescence (PL) quantum efficiency (QY=60.37 %) due to TADF mechanism. The emission color can be easily tuned from blue to green by synthesizing the mixed‐halide Cs 2 ZrBr x Cl 6− x (0≤ x ≤1.5) NCs. Femtosecond transient absorption and temperature dependent PL measurements are performed to clarify the emission mechanism. In addition, Bi 3+ ions are successfully doped into Cs 2 ZrCl 6 NCs, which further extends the PL properties. This work not only develops a new lead‐free halide perovskite NCs for potential optoelectronic applications, but also offers unique strategies for developing new inorganic phosphors.