Yue Yifei, Zhu Dongxia, Zhang Ning, Zhu Guangshan, Su Zhongmin
Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Department of Chemistry , Northeast Normal University , 5268 Renmin Street , Changchun , Jilin Province 130024 , P. R. China.
School of Chemistry and Environmental Engineering , Changchun University of Science and Technology , Changchun 130022 , P. R. China.
ACS Appl Mater Interfaces. 2019 May 1;11(17):15898-15904. doi: 10.1021/acsami.9b01059. Epub 2019 Apr 19.
Cesium lead halide perovskites (CsPbX, X = Cl, Br, and I) have emerged as an important class of color-tunable light-emitting materials in the past 4 years. However, single-CsPbX nanostructures with dual-color emission remain scarce. Here, we demonstrate dual-color emission from lead halide perovskite nanowires induced by the surface ligands, that is, oligomeric methoxypolyethylene glycol (MEOPEG). In addition to the characteristic emission from the host lattice, an unprecedented emission from the expanded band gap caused by MEOPEG is observed. The ratio of the two emission intensities can be easily adjusted by changing the concentration of the surface ligands. Moreover, the band gaps of CsPbX-MEOPEG can be further fine-tuned by a simple postsynthetic anion exchange process. As a result, white light-emitting diodes (WLEDs) with high-quality CIE coordinates of (0.33, 0.29) and a high color rendering index value (84) are realized. These CsPbX-MEOPEG materials, with tunable dual-color emission, may serve as ideal model systems for WLEDs, which will undoubtedly expand the applications of cesium lead halide perovskites.
在过去四年中，卤化铯铅钙钛矿（CsPbX，X = Cl、Br和I）已成为一类重要的可颜色调谐发光材料。然而，具有双色发射的单CsPbX纳米结构仍然稀缺。在此，我们展示了由表面配体，即低聚甲氧基聚乙二醇（MEOPEG）诱导的卤化铅钙钛矿纳米线的双色发射。除了主体晶格的特征发射外，还观察到由MEOPEG引起的带隙扩展产生的前所未有的发射。通过改变表面配体的浓度，可以轻松调节两种发射强度的比例。此外，CsPbX-MEOPEG的带隙可以通过简单的合成后阴离子交换过程进一步微调。结果，实现了具有高质量CIE坐标（0.33, 0.29）和高显色指数值（84）的白色发光二极管（WLED）。这些具有可调双色发射的CsPbX-MEOPEG材料可能成为WLED的理想模型系统，这无疑将扩大卤化铯铅钙钛矿的应用。
