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All‐Inorganic Perovskite Nanocrystals for High‐Efficiency Light Emitting Diodes: Dual‐Phase CsPbBr 3 ‐CsPb 2 Br 5 Composites
Author(s) -
Zhang Xiaoli,
Xu Bing,
Zhang Jinbao,
Gao Yuan,
Zheng Yuanjin,
Wang Kai,
Sun Xiao Wei
Publication year - 2016
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.201600958
Subject(s) - materials science , perovskite (structure) , nanocrystal , light emitting diode , phase (matter) , nanoparticle , quantum efficiency , band gap , composite number , optoelectronics , nanotechnology , chemical engineering , composite material , chemistry , organic chemistry , engineering
A dual‐phase all‐inorganic composite CsPbBr 3 ‐CsPb 2 Br 5 is developed and applied as the emitting layer in LEDs, which exhibited a maximum luminance of 3853 cd m –2 , with current density (CE) of ≈8.98 cd A –1 and external quantum efficiency (EQE) of ≈2.21%, respectively. The parasite of secondary phase CsPb 2 Br 5 nanoparticles on the cubic CsPbBr 3 nanocrystals could enhance the current efficiency by reducing diffusion length of excitons on one side, and decrease the trap density in the band gap on the other side. In addition, the introduction of CsPb 2 Br 5 nanoparticles could increase the ionic conductivity by reducing the barrier against the electronic and ionic transport, and improve emission lifetime by decreasing nonradiative energy transfer to the trap states via controlling the trap density. The dual‐phase all‐inorganic CsPbBr 3 ‐CsPb 2 Br 5 composite nanocrystals present a new route of perovskite material for advanced light emission applications.