Luminescence and energy transfer of Mn 2+ and Tb 3+ in Y 3Al 5O 12 phosphors

Abstract

Mn 2+ is an excellent luminescent ion with variable color from green, yellow to red in different hosts and has been widely utilized in recent years. The luminescent intensity of Mn 2+ in many hosts is so low that the correlative application is restricted. In the present paper, two methods, i.e. employing a charge compensator and introducing a sensitizer, were adopted to enhance the luminescence of Mn 2+ in Y 3Al 5O 12 (YAG). By employing Si 4+ as a charge compensator, the doping content of Mn 2+ ( x) in Y 3Mn x Al 5−2 x Si x O 12 can be lifted up to 0.4. Mn 2+ in YAG emits orange light in a broad band. The peak wavelength shifts from 586 to 593 nm with the increasing x. The luminescent intensity of Mn 2+ reaches its maximum when x = 0.1. Co-doping Tb 3+ into Mn 2+ doped YAG, the sensitization effect of Tb 3+ on Mn 2+ was observed clearly. The resonance energy transfer from Tb 3+ to Mn 2+ occurs because there is a well overlapping between emission spectrum of Tb 3+ and excitation spectrum of Mn 2+. A reasonable explanation for the sensitization effect of Tb 3+ on the luminescence of Mn 2+ was brought forward.