CsPbBrxI3-x thin films with multiple ammonium ligands for low turn-on pure-red perovskite light-emitting diodes
CsPbBrxI3-x thin films with multiple ammonium ligands for low turn-on pure-red perovskite light-emitting diodes
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DOI：
10.1007/s12274-020-3065-5
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发表时间：
2020-09
期刊：
影响因子：
9.9
通讯作者：
Maowei Jiang;Zhanhao Hu;L. Ono;Y. Qi
中科院分区：
文献类型：
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作者：
Maowei Jiang;Zhanhao Hu;L. Ono;Y. Qi
全无机α-CsPbBrxI 3-xperovskites具有纳米尺寸的微晶，在纯红光发光二极管（LED）应用中显示出巨大的潜力。目前，基于纳米α-CsPbBrxI 3-x微晶的CsPbBrxI 3-xLED主要通过经典的胶体方法制备，包括冗长的合成、纯化、配体或阴离子交换、薄膜浇铸等步骤。此外，这种混合卤化物系统在偏压下会产生严重的光谱漂移。在这份报告中，CsPbBrxI 3-x薄膜具有纳米尺寸的微晶制备通过将多个铵配体在一个步骤的旋涂路线。多个铵配体抑制了CsPbBrxI 3-x纳米颗粒的生长。这种CsPbBrxI 3-x薄膜受益于量子限制。相应的CsPbBrxI 3-xLED采用铟掺杂氧化锡（ITO）/聚（3，4-亚乙基二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT：PSS）/CsPbBrxI 3-x/[6，6]-苯基C61丁酸甲酯（PCBM）/浴铜灵（BCP）/Al的常规LED结构，在国际照明委员会（CIE）坐标（0.709，0.290）、（0.711，0.289）等处发射纯红色，其代表了所报道的纯红色钙钛矿LED的最高色纯度，并且非常好地满足CIE的Rec.2020要求（0.708，0.292）。CsPbBrxI 3-xLED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的高亮度以及偏压下良好的颜色稳定性。
All-inorganic α-CsPbBrxI3-xperovskites featuring nano-sized crystallites show great potential for pure-red light-emitting diode (LED) applications. Currently, the CsPbBrxI3–xLEDs based on nano-sized α-CsPbBrxI3-xcrystallites 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 CsPbBrxI3-xLEDs. Moreover, this mix-halide system may suffer from severe spectra-shift under bias. In this report, CsPbBrxI3-xthin 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 CsPbBrxI3-xnanograins. Such CsPbBrxI3-xthin films benefit from quantum confinement. The corresponding CsPbBrxI3-xLEDs, adopting a conventional LED structure of indium-doped tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/CsPbBrxI3-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 CsPbBrxI3-xLED 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.