nz9b02562_si_001.pdf (1.63 MB)
A Cocktail of Multiple Cations in Inorganic Halide Perovskite toward Efficient and Highly Stable Blue Light-Emitting Diodes
journal contribution
posted on 2020-03-13, 15:13 authored by Fang Yuan, Chenxin Ran, Lin Zhang, Hua Dong, Bo Jiao, Xun Hou, Jingrui Li, Zhaoxin WuBlue-emitting
materials and their light-emitting diodes (LEDs)
are always challenging in lighting and display applications. Recently,
perovskite LEDs (PeLEDs) with efficient and stable green/red emission
have made great progress, where external quantum efficiency (EQE)
over 20% has been reached. However, it is still a big challenge to
realize stable blue PeLEDs with high efficiency mainly because of
the poor film quality and unreasonable device structure. Herein, a
cocktail strategy, that is, multication (Cs/Rb/FA/PEA/K)Pb(Cl/Br)3, is demonstrated to improve both the efficiency and stability
of blue PeLEDs. Combined with the “insulator–perovskite–insulator”
structure, PeLEDs based on a multication (Cs/Rb/FA/PEA/K)Pb(Cl/Br)3 perovskite film show maximum EQE of 2.01% and maximum luminance
of 4015 cd/m2 at 484 nm. More importantly, the device exhibits
robust durability, and its half-lifetime is over 300 min under continuous
operation. The multication strategy could open up a new avenue for
the design of new blue-emitting materials for high-performing PeLEDs.