Sensitization of Mn2+ Luminescence by Eu2+: A Combined Study Using Optical Spectroscopy and Luminescence Dynamics Simulations.

Abstract

Owing to the intriguing luminescent feature, Mn2+-doped materials have attracted a lot of attention. Unfortunately, their application potential is hampered by the parity-forbidden nature of Mn2+ 3d-3d transition, and the insufficient excitation light absorption is the main obstacle. Although the use of a sensitization strategy effectively addresses this issue, explicit knowledge of the sensitization mechanism is insufficient, severely limiting the improvement of Mn2+ luminescence performance in a wide range of materials. Herein, the sensitization of Mn2+ luminescence is investigated in Eu2+, Mn2+-codoped SrMgP2O7 which has the high luminescence efficiency upon UV excitation. The electronic transition properties of Eu2+ and Mn2+ are studied by VUV-UV-vis spectroscopy, and the sensitization mechanism is elucidated by luminescence dynamics simulations. Efforts are also made to evaluate the impact of temperature variation on the sensitization efficiency. Based on these discussions, the collaboration of high-efficiency Eu2+ → Mn2+ energy transfer via dipole-dipole interaction and suppression of Mn2+ luminescence loss results in the significant sensitization of Mn2+ luminescence in Eu2+, Mn2+-codoped materials, which are essentially associated with probable orbital hybridization and weak electron-vibration interaction, respectively. Current research provides a practical guideline for analyzing the luminescence sensitization effect in the donor-acceptor system, which facilitates the development of materials with unique optical features.