摘要
Formamidinium lead bromide perovskite(FAPbBr3)nanocrystals have attracted increasing attention due to their greener photoluminescence(PL)and higher thermal stability in comparison to more popular methylammonium lead bromide perovskite(MAPbBr3).Here we proposed a-facile and highly reproducible room-temperature method for the preparation of fewlayer(1-4)two-dimensional(2D)FAPbBr3 nanoplatelets(NPs)with ultrapure green PL at 532 nm and high photoluminescence quantum yield(PLQY)of 88%.High-efficiency ultrapure green light-emitting diodes(LEDs)based on the few-layer 2D FAPbBr3 NPs were further demonstrated.The LEDs showed a maximum current efficiency(CE)of 15.31cd/A and an external quantum efficiency(EQE)of 3.53%,which are significantly better than the FAPbBr3 polycrystalline film-based LEDs reported so far.Significantly,the 2D FAPbBr3 NPs-based LEDs exhibited an ultrapure-green color emission that could cover 97%of the Recommendation 2020(Rec.2020)color standard and 114%of the national television system committee(NTSC)standard in the CIE 1931 color space.Moreover,the devices possessed a much better stability than the MAPbBr3 nanocrystals-based LEDs in air;the half lifetime T50 of our devices was about 5 times Ion ger than that of MAPbBr3 nan ocrystals-based LEDs.This work demonstrates the great potential of FAPbBr3 NPs in light-emitting devices for future ultrahigh-resolution displays.
基金
the National Basic Research Program of China(No.2016YFA0202400)
the National Natural Science Foundation of China(Nos.51672180,51622306,and 21673151)
Collaborative Innovation Center of Suzhou Nano Science&Technology Qing Lan Project,111 project,and the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
