White-Light Generation and Energy Transfer in Y2O3:Bi,Eu Phosphor for Ultraviolet Light-Emitting Diodes

3þ,yEu3þ phosphors were prepared by co-precipitation method and characterized by X-ray diffraction and photolu-minescence spectra. Under the excitation of 320–350 nm ultraviolet light, these phosphors show three emission bands; the one observed at 612 nm is attributed to Eu3þ and the other two bands were found to center at 410 and 490 nm, which originate from Bi3þ 3P1!1S0 transitions at two different Y3þ sites. The energy transfer from Bi3þ to Eu3þ is discussed. By appropriate tuning of activator concentration and excitation wavelengths, we obtained white light emission. The results indicate that Y2xyO3:xBi 3þ,yEu3þ are potential phosphors for white light-emitting diode applications.