柠檬酸配体改善绿光钙钛矿发光二极管发光效率

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关键词：钙钛矿；发光二极管；配体；外量子效率中图分类号：0482.31；TN312.8 文献标识码：ADOI：10.37188/CJL.20250240 CSTR：32170.14.CJL.20250240

Citric Acid Ligands for Enhancing Efficiency of Green Perovskite Light-emitting Diodes

BAIWenhao 1，2 ，RENGuanhua1，SONGKunjie'，YERZHAT Didar'，ZHOU Jiajing' XUAN Tongtong1，3*，XIE Rongjun1，3*

（1.CollegeofMaterials，XiamenUniversity，Xiamen361oo5，China; 2.CollegeofPhysical Scienceand Technology，Xiamen University，Xiamen 361Oo5，China; 3.ShenzhenResearchInstitute，XiamenUniversity，Shenzhen518ooo，China） * CorrespondingAuthors，E-mail：ttxuan@xmu.edu.cn;rjxie@xmu.edu.cn

Abstract：Metal halide perovskite nanocrystals （ CsPbX3 ）have emerged as promising candidate materials for display technologies due to their excellnt optoelectronic properties.However，the weak coordination and long-chain structure of conventional ligands，such as oleic acid and oleylamine（OA/OLA），result in surface defects and hinderedcarier transport，which significantly limit theperformanceenhancementofperovskitelight-emiting diodes （PeLEDs）. In this study，a short-chain，strongly chelating citric acid（CA）ligand was introduced.This ligand formsboth coordination bonds and hydrogenbondswith the CsPbB 13 surface through its carboxyl（ - COOH）and hydroxyl （ - OH） functional groups，effectively passivating surface defects of the nanocrystals. Experimental results combined with density functional theory（DFT）calculations demonstrate thattheadsorptionenergyof citricacid ligands isconsiderablyhigherthan thatoftraditionalOA/OLA ligands.This leads toamore uniformnanocrystal size distribution，significantly enhanced photoluminescencequantum yield（PLQY），and a substantial reduction in he non-radiative recombinationrate.Green-emitting PeLEDs based on citric acid-modified CsPbBr3 nanocrystals exhibit excellnt electroluminescent performance，achieving a peak external quantum efficiency（EQE）of 13.58% and a peak current efficiency of 42.93cd/A.This study presents a novel strategy for surface defect engineering of perovskites through cost-efectiveligand design，and the multidentate chelating mechanismmay be applicable to other optoelectronic devices such as photodetectors and solar cells.

Keywords：perovskite； light-emitting diode; ligands；external quantum efficiency

1引言

近年来，金属卤化物钙钛矿（ CsPbX3 ， X=Cl Br，I纳米晶因其优异的光电特性，包括长载流子扩散长度、可调谐窄带发射、高吸收系数及高光致发光量子效率（PLQY）等，在下一代全彩显示领域展现出重要应用价值[6]。（剩余15165字）