Analysis of the structure and abnormal photoluminescence of a red-emitting LiMgBO3:Mn2+ phosphor

作者：Wu, Liwei; Bai, Yuxing; Wu, Li; Yi, Huan; Zhang, Xinzheng; Zhang, Lixin; Kong, Yongfa; Zhang, Yi^*; Xu, Jingjun

来源：Dalton Transactions, 2018, 47(37): 13094-13105.

DOI：10.1039/c8dt02450b

• ELECTRON-SPIN-RESONANCE
• INITIO MOLECULAR-DYNAMICS
• STRUCTURE REFINEMENT
• OPTICAL-PROPERTIES
• CRYSTAL-STRUCTURE
• Y2O3-EU PHOSPHOR
• SPRAY-PYROLYSIS
• LUMINESCENCE
• MN2+
• EMISSION

Mn2+ is attracting increasing attention due to its potential application as an activated ion in the phosphors. In this study, a rare-earth free phosphor, LiMgBO3:Mn2+, was synthesized using a high temperature solid-state reaction. Combined with X-ray diffraction and PL/PLE as well as first-principles calculation, the coordination environment of Mn2+ was disclosed, revealing that Mn2+ ions were inclined to occupy two partially filled Li sites. Under 427 nm-excitation, an abnormal deep red emission band centered at 705 nm was observed. This was due to the strong crystal field environment of Mn2+ induced by the extremely distorted five-coordinated sites, which was proved by the electronic band structure obtained from the density functional theory calculations. In addition, the luminescence intensity and thermal stability of LiMgBO3:Mn2+ was significantly enhanced when Li+ was replaced by Na+ and K+. This study disclosed the origin of the abnormal luminescence of Mn2+ in LiMgBO3 and further enriched our understanding of the abnormal luminescence of Mn2+ in special crystal structures (five-coordinated configuration).

• 出版日期2018-10-7
• 单位南开大学