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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.
Eu-doped GaN was prepared by solid-state reaction with Ga_2O_3, Eu_2O_3 and NH_3 applied as raw materials. 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 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 increased to 293 K, the ultraviolet luminescence disappeared. However, the intensity of Eu ~ (3+) luminescence was nearly not affected by temperature. A donor-acceptor pair (DAP) model based on O_N and Mg_ (Ga) was pointed out for instruction the luminescence mechanism. The cathodo-luminescence spectra of nom inal 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.