Photoluminescence and energy transfer properties of Eu2+ and Tb3+ co-doped gamma aluminum oxynitride powders

Gamma-AlON: 0.2Eu2+, Tb3+ phosphors were firstly synthesized via a high temperature solid-state reaction. For the phosphors, luminescence properties as well as energy transfer mechanism were investigated in detail. The energy transfer from Eu2+ to Tb3+ in the γ-AlON host was ascribed to the dipole-dipole mechanism, and the efficiency and critical distance in the energy transfer process were also estimated. γ-AlON: 0.2Eu2+, Tb3+ phosphors showed a broad-band emission centered at about 405 nm and other several emission peaks, which were assigned to the 5d-4f transition of Eu2+ ions and the 5D4-7FJ (J = 6, 5, 4, and 3) characteristic transitions of Tb3+ ions, respectively. The results indicated that γ-AlON: 0.2Eu2+, Tb3+ phosphors have great potential application in white light-emitting diodes due to its broad-band excitation in the ultraviolet range and the high-efficient green light emission.