Xie Cong, Zhao Yubin, Shi Wenbin, Yang Ping
School of Material Science and Engineering, University of Jinan, Jinan 250022, PR China.
Langmuir. 2021 Jan 26;37(3):1183-1193. doi: 10.1021/acs.langmuir.0c03066. Epub 2021 Jan 12.
The existing defects on the surface of CsPbX nanocrystals (NCs) resulted in the decrease of the photoluminescence quantum yields (PLQYs) of NCs. In this study, we developed a simple strategy, which can make the treated CsPbX NCs exhibit high PLQYs and better stability by CdX post-treatment at room temperature. The treated CsPbX NCs were characterized by X-ray diffraction (XRD) patterns and PL spectra. The shape, size, and crystal structure of the NCs remained unchanged after Cd ion treatment. The PLQYs of CsPbCl increased from 24 to 73% and the PLQYs of CsPbBr NCs increased from 85 to 92% after treatment. The significant enhancement of PLQYs is ascribed to the effective passivation of surface defects, in which Cd and X ions occupied the Pb-X vacancies existing on the surface of the NCs. In addition, this strategy was also applied to a mixed halide perovskite. The practical application of CsPbX NCs will be extended by this method.
CsPbX纳米晶体（NCs）表面存在的缺陷导致了NCs光致发光量子产率（PLQYs）的降低。在本研究中，我们开发了一种简单的策略，通过在室温下用CdX进行后处理，可使处理后的CsPbX NCs表现出高PLQYs和更好的稳定性。通过X射线衍射（XRD）图谱和PL光谱对处理后的CsPbX NCs进行了表征。Cd离子处理后，NCs的形状、尺寸和晶体结构保持不变。处理后，CsPbCl的PLQYs从24%提高到73%，CsPbBr NCs的PLQYs从85%提高到92%。PLQYs的显著提高归因于表面缺陷的有效钝化，其中Cd和X离子占据了NCs表面存在的Pb - X空位。此外，该策略也应用于混合卤化物钙钛矿。通过这种方法将扩展CsPbX NCs的实际应用。
