Long persistent phosphors (LPPs) with ultraviolet (UV) luminescence have great potential for application in the fields of biomedicine, environmental, and catalysis. However, it is currently limited by the design and development of remarkable UV LPPs with a suitable spectral region and an ultralong afterglow decay time. Herein, we develop a new type of Bi3+-activated LiScGeO4 LPP, which exhibits bright ultraviolet-A (UVA) persistent luminescence (PersL). Because of the existence of numerous stabilized effective traps, the as-synthesized phosphors can undergo an ultralong PersL decay time far longer than 12 h. The PersL properties, effective trap depths, distributions, and types, as well as the possible mechanism for the PersL behavior of LiScGeO4:Bi3+, are comprehensively surveyed utilizing PersL excitation spectra, PersL decay analyses, thermoluminescence experiments, and X-ray photoelectron spectroscopy. This work can cover the shortage of LPPs in the UV region and also can lay the foundation for the development of more excellent UV LPPs toward versatile novel applications.
Yue Zhong,Tao Su,Jing Xie,Chao Wang,Wenming Wang,Yan Pan,Xiantao Wei,Yong Li
Mn-doped phosphors exhibiting self-reduction behavior have garnered significant attention in the study of luminescent materials due to the defects generated during the self-reduction process and their unique luminescent behavior. In this paper, LiScGeO 4 red phosphors activated by the self-reduction of Mn 4+ to Mn 2+ were synthesized by high-temperature solid-state reaction in an air atmosphere. The defects generated during the self-reduction process were leveraged to attain exceptional anti-thermal quenching characteristics, with luminescent intensity at a high temperature of 430 K being 1.23 times compared to that at room temperature of 300 K. In addition, a peculiar phenomenon occurred where the emission peak initially blueshifts and subsequently redshifts with the increasing temperature. This study includes an analysis of the Rietveld-refined lattice parameters and surface micromorphology of the samples. The theoretical energy gap of the perfect LiScGeO 4 matrix was calculated using density functional theory . Furthermore, the unique emission peak shift characteristics of Mn 2+ were elucidated through the interaction between Mn 2+ ions and the strength of the crystal field . Utilizing a defect model, the self-reduction mechanism and the anti-thermal quenching behavior were clarified. These findings will enhance the understanding of the effects of crystal defects and ion pair interactions on luminescent materials , and encourage further explorations of self-reducing phosphors to develop new high thermal stability phosphors for practical applications.
危险品化学品经营许可证（带存储）