Luminescence and energy transfer of Mn2+ and Tb3+ in Y3Al5O12 phosphors

Mn2+ 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 Mn2+ 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 Mn2+ in Y3Al5O12 (YAG). By employing Si4+ as a charge compensator, the doping content of Mn2+ (x) in Y3MnxAl5-2xSixO12 can be lifted up to 0.4. Mn2+ 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 Mn2+ reaches its maximum when x = 0.1. Co-doping Tb3+ into Mn2+ doped YAG, the sensitization effect of Tb3+ on Mn2+ was observed clearly. The resonance energy transfer from Tb3+ to Mn2+ occurs because there is a well overlapping between emission spectrum of Tb3+ and excitation spectrum of Mn2+. A reasonable explanation for the sensitization effect of Tb3+ on the luminescence of Mn2+ was brought forward. (C) 2011 Elsevier B.V. All rights reserved.