Scalable synthesis of highly luminescent and stable thiocyanate based CsPbX3 perovskite nanocrystals for efficient white light-emitting diodes
Scalable synthesis of highly luminescent and stable thiocyanate based CsPbX3 perovskite nanocrystals for efficient white light-emitting diodes
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DOI：
10.1016/j.jallcom.2020.158501
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发表时间：
2021-04
影响因子：
6.2
通讯作者：
S. Thapa;G. Adhikari;Hongyang Zhu;P. Zhu
中科院分区：
文献类型：
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作者：
S. Thapa;G. Adhikari;Hongyang Zhu;P. Zhu
全无机卤化铅钙钛矿材料因其优异的光物理性能而成为光电子器件的研究热点。然而，卤化物钙钛矿的稳定性问题阻碍了其实际应用。首次用硫氰酸盐(SCN-−)改善了皂化沉淀法制备的CsPbX3钙钛矿纳米晶的光学性质和稳定性。此外，本工作还提供了一种简单、经济的合成方法，可在常温和常压下操作。具体地说，无论−的大小和形状如何，随着其浓度的增加，由于陷阱态更好的钝化，量子产率几乎增加了10%，并且在几天内对空气和湿气保持稳定。可调谐发射(454-645 nm)跨越可见光光谱的展示和3D打印薄层的设计促进了绿色、黄色和红色发射颜色转换层的制备。得益于合成的转换层中光子损耗的减少，这些颜色转换层的应用产生了具有显著光学特性的明亮的中性白光(5184 K)。因此，本实验研究为SCN−制备高质量CsPbX3NCs提供了一条低温合成途径，并揭示了该NCs的实际应用前景。
All-inorganic lead halide perovskites have attracted considerable attention as promising materials for optoelectronic devices because of their excellent photophysical properties. However, the stability issue of halide perovskites precludes their practical applications. For the first time, this work exhibits that the optical properties and stability of CsPbX3perovskite nanocrystals (NCs), prepared by the saponification precipitation method, can be improved using thiocyanate (SCN−). Besides, this work offers a simple and economical synthesis method operable at room temperature and ambient atmosphere. Specifically, an increasing concentration of SCN−induces an increase in quantum yield almost by 10% and stability against air and moisture over several days due to the better passivation of trap states, irrespective of size and shape variation of NCs. The demonstration of tunable emission (454–645 nm) across the visible spectrum and the design of 3-D printed thin layers facilitate the preparation of green, yellow, and red-emitting color conversion layers. Benefitted from the decreased photon loss in as-synthesized conversion layers, the application of these color conversion layers results in a bright neutral white light (5184 K) with remarkable optical properties. Hence, this experimental study offers a low-temperature synthetic path for the scalable preparation of high-quality CsPbX3NCs processed with SCN−and reveals the practical applications of such NCs.