Abstract
Bismuth-doped Y2O3:EuY2O3:Eu is used as red phosphors with very high efficiency and appropriate emission wavelength. These red phosphors have been synthesized by homogeneous coprecipitation and solid-state reaction without any flux, which may be used in the field of white LEDs (light-emitting diodes). The crystal structure of bismuth-doped Y2O3:EuY2O3:Eu is cubic (space group: Ia3¯Ia3¯ ) with C2C2 and S6S6 sites. Y2O3:EuY2O3:Eu can be excited by charge transfer (254nm)(254nm) and direct excitation (about 350‐420nm350‐420nm ). When incorporated in Y2O3:EuY2O3:Eu phosphors, Bi3+Bi3+ ions act as a sensitizer for Eu3+Eu3+ ions under 350nm350nm radiation. The energy transferred from Bi3+Bi3+ ions to Eu3+Eu3+ ions by a nonradiation process resulted in the final emission from excited Eu3+Eu3+ ions. The emission is observed at 610<mml:mspace...