Effects of Doping Trace Sm^(3+) and Gd^(3+) on Luminescent Character of Y_2O_2S∶Eu^(3+)

摘要

After trace Sm3+ ions and Gd3+ ions doping, the emission intensity of red phosphors Y2O2S∶Eu3+ was enhanced and the voltage character （relation between emission intensity and excitation voltage） was improved while the other properties of physics and chemistry were not changed. The origins of enhancement and improvement are discussed. Probably the distortion and the defect of crystals are decreased by the substitution of Gd3+ for Y3+ instead of Eu3+ for Y3+, and thus the Eu3+ crystal field is improved, and radiationless process and energy loss resulted from crystal defect are weakened, which leads to increased luminescence intensity and voltage character improvement. The overlapping fluorescent spectra of Y2O2S∶Sm3+ emission and Y2O2S∶Eu3+ excitation as well as Eu3+ excitation spectra containing Sm3+ excitation transitions spectra lead to the possibility of resonance energy transfer from Sm3+ ions to Eu3+ ions, and the sensitization of Sm3+ ions to Eu3+ ions is achieved effectively.