镧掺杂的普适性策略提升铅卤钙钛矿多晶薄膜光致发光性能用以背光显示  

A generic lanthanum doping strategy enabling efficient lead halide perovskite luminescence for backlights

作　　者：刘永杰 王成 陈国毅 王舒欣 余知秋 王倜 柯维俊 方国家 Yongjie Liu;Cheng Wang;Guoyi Chen;Shuxin Wang;Zhiqiu Yu;Ti Wang;Weijun Ke;Guojia Fang(Key Laboratory of Artificial Micro-and Nano-Structures of Ministry of Education,School of Physics and Technology,Wuhan University,Wuhan 430072,China)

机构地区：[1]Key Laboratory of Artificial Micro-and Nano-Structures of Ministry of Education,School of Physics and Technology,Wuhan University,Wuhan 430072,China

出　　处：《Science Bulletin》2023年第10期1017-1026,M0003,M0004,共12页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(12134010,62074117,and 12174290);the Natural Science Foundation of Hubei Province,China(2021CFB039)。

摘　　要：金属卤化物钙钛矿多晶薄膜因其低廉的成本以及可大面积制备的优势受到研究者的广泛关注.然而,钙钛矿多晶薄膜的光致发光量子效率和稳定性仍然无法媲美钙钛矿量子点,也无法满足显示技术要求.本文采用镧离子掺杂策略,提高钙钛矿多晶薄膜的发光性能,进一步提升了钙钛矿材料商业化的可能性.镧离子进入晶格可大大改善晶体质量,过量的镧离子和钙钛矿前驱液自组装形成了(FA,Cs)2LaBr5这种多能级物质,因此构建了新型能量漏斗,增强了钙钛矿主体发光性能.最终,镧掺杂FA0.7Cs0.3PbBr3钙钛矿薄膜实现了99.5%的光致发光量子效率.得益于镧掺杂带来的离子迁移活化能和可迁移离子形成能的提升,优化后的钙钛矿多晶薄膜也实现了近1000天的储存半衰期(T50)和400小时的持续光照稳定性(T90).此外,得益于多能级物质的自组装形成,镧掺杂的方式对于全可见光波段钙钛矿材料发光都具有明显的增强作用.由此得到的高纯高效三基色钙钛矿发光覆盖了Rec.2020色域标准的98.9%,这项工作大大推进了钙钛矿多晶薄膜在液晶显示技术背光板中的应用.Metal halide perovskites films have attracted great interest because of their solution-proceed fabrication and potential applications for next-generation displays.However,their non-ideal photoluminescence quantum efficiency(PLQE)and stability still does not meet the requirements of displays.Here,we adopt lanthanum ion(La3+)doping strategy to enhance its luminescence performance and the possibility of taking it to commercialization.In addition to the entry of lanthanum ions into the lattice to greatly improve the crystal quality,the excess La3+gives rise to the formation of newly developed formamidinium cesium lanthanum bromine,(FA,Cs)2LaBr5,which provides additional energy transport pathways,therefore concentrating more energy onto the perovskite host.Consequently,a near-unity PLQE of 99.5%is realized in standardized green-emission cesium(Cs)/formamidinium(FA)mixed FA0.7Cs0.3PbBr3 perovskite films.The introduction of La3+can also lead to markedly stability with nearly 1000 days’shelf storage half-lifetime and 400 hours’light-irradiation T90 lifetime as well as much-enhanced color purity.Moreover,the films with La3+doping enable full-visible spectral enhancement and high-performance white light emission and trichromatic luminescence with 98.9%coverage of the color gamut area required for the Rec.2020 standard,which suggest that perovskite films have great application potential for backlights in liquid crystal display technologies.

关 键 词：Backlightdisplays Lanthanum doped perovskites Formamidinium cesium lanthanum BROMINE Full-visiblespectral emission Perovskiteluminescence 

分 类 号：TN873[电子电信—信息与通信工程] TB383.2[一般工业技术—材料科学与工程]