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 few-layer (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 15.31 cd/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 longer than that of MAPbBr₃ nanocrystals-based LEDs. This work demonstrates the great potential of FAPbBr₃ NPs in light-emitting devices for future ultrahigh-resolution displays.

中文翻译：

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用于超纯绿色和高效发光二极管的几层甲ami溴化铅纳米片

与更流行的甲基溴化铵铵钙钛矿（MAPbBr ₃）相比，甲酰胺基溴化钙钛矿（FAPbBr ₃）纳米晶体因其更绿色的光致发光（PL）和更高的热稳定性而受到越来越多的关注。在这里，我们提出了一种简便且高度可重现的室温方法，用于制备几层（1-4）二维（2D）二维FAPbBr ₃纳米片（NPs），该纳米片具有532 nm的超纯绿色PL和高光致发光量子产率（PLQY） ）的88％。基于几层2D FAPbBr ₃的高效超纯绿色发光二极管（LED）NP被进一步证实。这些LED的最大电流效率（CE）为15.31 cd / A，外部量子效率（EQE）为3.53％，明显优于迄今为止报道的基于FAPbBr3多晶膜的LED。值得注意的是，基于2 FAPbBr ₃ NP的LED表现出超纯绿色的颜色，可覆盖CIE 1931中2020年建议2020（2020年建议）颜色标准的97％和国家电视系统委员会（NTSC）标准的114％。色彩空间。此外，该器件在空气中的稳定性比基于MAPbBr ₃纳米晶体的LED更好。我们设备的半衰期T50大约是MAPbBr _3的5倍基于纳米晶体的LED。这项工作证明了FAPbBr ₃ NP在发光器件中对于未来超高分辨率显示器的巨大潜力。