Bulk Assembly of Zero-Dimensional Organic Lead Bromide Hybrid with Efficient Blue Emission
Bulk Assembly of Zero-Dimensional Organic Lead Bromide Hybrid with Efficient Blue Emission
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DOI：
10.1021/acsmaterialslett.9b00333
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发表时间：
2019-12-01
影响因子：
11.4
通讯作者：
Ma, Biwu
中科院分区：
文献类型：
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作者：
Lin, Haoran;Zhou, Chenkun;Ma, Biwu
零维（0D）有机金属卤化物杂化物是一类新兴的发光材料，具有优异的光致发光量子效率（PLQEs），这要归功于它们完美的“主客”结构，发光金属卤化物物种通过离子键周期性地“嵌入”在宽带隙有机阳离子基质中。然而，对于这类材料来说，实现有效的蓝色发射是具有挑战性的，因为金属卤化物的结构扭曲通常会导致大的斯托克斯位移。在这里，我们报道了一种高发光蓝光的有机溴化铅，（C13H19N4）(2)PbBr4，其峰值发射为460 nm (2.70 eV)，半峰宽（FWHM）为66 nm (0.40 eV)， Stokes位移为111 nm (0.85 eV)， PLQE接近40%。单晶结构分析表明，PbBr42-各组分呈近跷跷板结构，与苄基六亚甲基四铵（C13H19N4+）有机阳离子配位。与先前报道的0D有机金属卤化物杂化体相比，相对较小的Stokes位移归因于pb6s(2)孤对和刚性有机阳离子基质的低化学反应性。（C13H19N4）(2)PbBr4在空气中也表现出优异的稳定性，在环境条件下性能变化很小甚至没有变化超过一年。
Zero-dimensional (0D) organic metal halide hybrids are an emerging class of light emitting materials with exceptional photo-luminescence quantum efficiencies (PLQEs), thanks to their perfect "host-guest" structures with light emitting metal halide species periodically "embedded" in a wide band gap organic cationic matrix through ionic bonds. However, achieving efficient blue emissions is challenging for this class of materials, as structural distortions of metal halides often lead to large Stokes shifts. Here we report a highly luminescent blue emitting 0D organic lead bromide, (C13H19N4 )(2)PbBr4, with a peak emission of 460 nm (2.70 eV), a full width at half maximum (FWHM) of 66 nm (0.40 eV), a Stokes shift of 111 nm (0.85 eV), and a PLQE of similar to 40%. Single crystal structure analysis shows that individual PbBr42- species adopt a nearseesaw structure, which are coordinated to benzyl-hexamethylenetetrammonium (C13H19N4+) organic cations. The relatively small Stokes shift as compared to those of previously reported 0D organic metal halide hybrids are attributed to the low chemical reactivity of Pb 6s(2) lone pairs and the rigid organic cationic matrix. (C13H19N4)(2)PbBr4 also shows exceptional stability in air with little-to-no change of properties for more than a year in ambient conditions.