溴化钠作用下零维钙钛矿Cs4PbBr6的转化及发光特性

NaBr-triggered Transformation and Luminescence Performance of Zero-dimensional Perovskite Cs4PbBr6

具有相同元素组成的零维结构钙钛矿Cs 4PbX 6是一种新的合成CsPbX 3的前驱体物质。CsPbX 3比Cs 4PbX 6更适于充当高效发光材料的基质。本研究报道了廉价的溴化钠作用下三方相的Cs 4PbBr 6到单斜相CsPbBr 3的转变。Cs 4PbBr 6和CsPbBr 3在紫外光激发下均能发出纯正的绿色荧光(在可见光区呈现半峰宽窄的单一发射峰)。此外,还考察了不同量的溴化钠对样品的物相结构与发光特性的影响。随着溴化钠的量的增加,生成的Cs 4PbBr 6逐渐减少而CsPbBr 3逐渐增加。该转变可能是溴化钠诱导下CsBr被抽提而实现的。

Zero-dimensional lead halide perovskite Cs 4PbX 6 has the same chemical elements as CsPbX 3,which can act as a novel precursor for obtaining CsPbX 3.Compared to the former,the latter is an excellent host for phosphor.A simple method that enabled the efficient conversion of rhombohedral Cs 4PbBr 6 to monoclinic CsPbBr 3 triggered by low-cost NaBr was reported.Both the as-obtained Cs 4PbBr 6 and CsPbBr 3 emitted pure green-light under excitation of UV,which exhibited single emission peak with small half-peak bandwidth in UV-visible light region.Moreover,the effects of feeding dosage of NaBr on phase structure and photoluminescence performance were investigated.With the increasing of feeding dosage of NaBr,as-prepared Cs 4PbBr 6 decreased while CsPbBr 3 gradually increased.This transformation may be due to extraction of CsBr triggered by NaBr.