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Simultaneous Strontium Doping and Chlorine Surface Passivation Improve Luminescence Intensity and Stability of CsPbI 3 Nanocrystals Enabling Efficient Light‐Emitting Devices
Author(s) -
Lu Min,
Zhang Xiaoyu,
Zhang Yu,
Guo Jie,
Shen Xinyu,
Yu William W.,
Rogach Andrey L.
Publication year - 2018
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201804691
Subject(s) - passivation , materials science , photoluminescence , quantum yield , nanocrystal , dopant , electroluminescence , ion , doping , luminescence , ionic radius , perovskite (structure) , analytical chemistry (journal) , optoelectronics , nanotechnology , crystallography , optics , chemistry , fluorescence , physics , organic chemistry , layer (electronics) , chromatography
A method is proposed to improve the photo/electroluminescence efficiency and stability of CsPbI 3 perovskite nanocrystals (NCs) by using SrCl 2 as a co‐precursor. The SrCl 2 is chosen as the dopant to synthesize the CsPbI 3 NCs. Because the ion radius of Sr 2+ (1.18 Å) is slightly smaller than that of Pb 2+ (1.19 Å) ions, divalent Sr 2+ cations can partly replace the Pb 2+ ions in the lattice structure of perovskite NCs and cause a slight lattice contraction. At the same time, Cl − anions from SrCl 2 are able to efficiently passivate surface defect states of CsPbI 3 nanocrystals, thus converting nonradiative trap states to radiative states. The simultaneous Sr 2+ ion doping and surface Cl − ion passivation result in the enhanced photoluminescence quantum yield (up to 84%), elongated emission lifetime, and improved stability. Sr 2+ ‐doped CsPbI 3 NCs are employed to produce light‐emitting devices with a high external quantum yield of 13.5%.