All-inorganic α-CsPbBr_xI_3-x perovskites featuring nano-sized crystallites show great potential for pure-red light-emitting diode (LED) applications. Currently, the CsPbBr_xI_3–x LEDs based on nano-sized α-CsPbBr_xI_3-x crystallites have been fabricated mainly via the classical colloidal route including a tedious procedure of nanocrystal synthesis, purification, ligand or anion exchange, film casting, etc. With the usually adopted conventional LED device structure, only high turn-on voltages (> 2.7) have been achieved for CsPbBr_xI_3-x LEDs. Moreover, this mix-halide system may suffer from severe spectra-shift under bias. In this report, CsPbBr_xI_3-x thin films featuring nano-sized crystallites are prepared by incorporating multiple ammonium ligands in a one-step spin-coating route. The multiple ammonium ligands constrain the growth of CsPbBr_xI_3-x nanograins. Such CsPbBr_xI_3-x thin films benefit from quantum confinement. The corresponding CsPbBr_xI_3-x LEDs, adopting a conventional LED structure of indium-doped tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/CsPbBr_xI_3-x/[6, 6]-phenyl C61 butyric acid methyl ester (PCBM)/bathocuproine (BCP)/Al, emit pure-red color at Commission Internationale de l’éclairage (CIE) coordinates of (0.709, 0.290), (0.711, 0.289), etc., which represent the highest color-purity for reported pure-red perovskite LEDs and meet the Rec. 2020 requirement at CIE (0.708, 0.292) very well. The CsPbBr_xI_3-x LED shows a low turn-on voltage of 1.6 V, maximum external quantum efficiency of 8.94%, high luminance of 2,859 cdm⁻², and good color stability under bias.

所有无机α-CsPbBr _X我_{3- X}钙钛矿设有纳米尺寸的微晶显示纯红色发光二极管（LED）的应用的巨大潜力。目前，CsPbBr _X我_{3- X} LED的基于纳米尺寸的α-CsPbBr _X我_{3- X}微晶已经通过包括纳米晶体合成，纯化的繁琐过程经典胶体路线主要制造，配位体或阴离子交换，膜流延使用通常采用的常规LED器件结构，对于CsPbBr _x I _{3- x}仅实现了高开启电压（> 2.7）。发光二极管。而且，该混合卤化物系统在偏压下可能遭受严重的光谱偏移。在此报告中，通过一步旋涂方式掺入多个铵配体，制备了具有纳米微晶的CsPbBr _x I _{3- x}薄膜。多个铵配体限制了CsPbBr _x I _{3- x}纳米颗粒的生长。这种CsPbBr _x I _{3- x}薄膜受益于量子限制。相应的CsPbBr _x I _{3- x} LED，采用掺杂铟锡氧化物（ITO）/聚（3,4-乙撑二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT：PSS）/ CsPbBr _x的常规LED结构I _{3- x} / [6，6]-苯基C61丁酸甲酯（PCBM）/巴果嘌呤（BCP）/ Al，在国际照明委员会（CIE）坐标为（0.709，0.290）时发出纯红色，（0.711，0.289）等，代表报道的纯红色钙钛矿LED的最高色纯度，并符合Rec。CIE的2020年要求（0.708，0.292）非常好。CsPbBr _x I _{3- x} LED显示出1.6 V的低开启电压，8.94％的最大外部量子效率，2,859 cdm ^-2的高亮度以及在偏压下的良好色彩稳定性。