Eu-doped GaN was prepared by solid-state reaction with Ga_2O_3,Eu_2O_3 and NH_3 applied as raw materials.The structural and optical properties were investigated.According to XRD results,wurtzite-type GaN powder without Eu_2O_3phase was obtained at 1000℃ and the grain size was about 20 run.Compared to the undoped GaN powder,all the Raman peaks of Eu-doped GaN powder were shifted towards lower phonon frequency about 2-6 cm^(-1),which may be resulted from the strain caused by the Eu^(3+) doping.The cathodo-luminescence(CL) spectra were measured from 80 to 293 K.Ultraviolet luminescence and Eu^(3+) luminescence were both observed when the temperature was below 200 K.When the temperature was increased to 293 K,the ultraviolet luminescence disappeared.However,the intensity of Eu^(3+) luminescence was nearly not influenced by temperature.A donor-acceptor pair(DAP) model based on O_N and Mg_(Ga) was pointed out for explaining the luminescence mechanism.The cathodo-luminescence spectra of nominal 1.0%,2.0%,3.0%and 5.0%(mole fraction) Eu-doped GaN at room temperature were summarized,which suggestes the 2.0%Eu-doped GaN has the highest Eu luminescent intensity.
WANG XiaodanMO YajuanSHI JianpingZENG XionghuiWANG JianfengXU Ke
