Broadband Laser-Induced Luminescence Generated in the Visible and Near-Infrared Ranges from Nontransparent CsPbCl3:Yb3+ Perovskite Ceramics

All inorganic perovskites with the general formula ABX3 (A = alkaline cation, B = lead ions, and X = halide anion) in the form of colloids have become very popular in recent years due to their extraordinary spectroscopic properties, which can be additionally modulated by changing their structural composition. Here, we report for the first time a novel study considering nontransparent CsPbCl3:10%Yb3+ ceramics that exhibit broadband laser-induced emission (LIE) with warm color (CRI = 96) upon exposure to a high-power-density infrared beam. It was found that the analyzed phenomenon strongly depends on the excitation power density and the pressure around the sample. Moreover, threshold behavior was observed, characterized by a significant increase in luminescence intensity already from the excitation of 0.2 W. The investigated material exhibits extremely strong photoconductivity. During the spectroscopic measurements of LIE, it was found that the current value varies by more than 4 orders of magnitude. Because of the relatively low sample temperature during the experiment, a LIE generation mechanism based on the creation of ytterbium mixed valence ion pairs and intervalence charge transfer (IVCT) transitions was proposed.