Self-crystallization mechanism of CsPb(Cl/Br)3 in tellurite glass-ceramics controlled by phase separation

Abstract

To solve the problem of the narrow spectrum adjustable range of CsPbX₃ PeQDs (perovskite quantum dots) in tellurite glass, the phase separation method by introducing MgO is first adopted to prepare CsPbCl_2.5Br_0.5 PeQDs, and the crystallinity of CsPbCl_2.5Br_0.5 PeQDs increases with the MgO concentration. By analyzing the results of SEM, Raman, and FTIR spectra, it is demonstrated that the occurrence of liquid/liquid phase separation notably depends on the changes in the glass-ceramic structure. As a result, the formation of self-crystallized CsPbCl_2.5Br_0.5 PeQDs can be promoted. Subsequently, by adjusting the ratio of Cl/Br, the self-crystallized CsPbCl_3−XBr_X (X = 0, 0.5, 1, 1.5, 3) PeQDs are prepared with a blue-green tunable PL spectrum from 414 nm to 522 nm. Meanwhile, the prepared CsPb(Cl/Br)₃ PeQD glass-ceramics have adjustable band gaps and excellent stability. This work provides a more energy-efficient method to synthesize CsPbX₃ PeQDs and broaden the tunable range of blue and green spectra of CsPbX₃ PeQDs in tellurite glass systems.