Charge-transfer nature in luminescence of YNbO4 : Bi blue phosphor

Abstract

Bismuth doped yttrium niobate (YNbO4:Bi) is a potential blue phosphor for field emission displays application. It is observed after introducing Bi ions that cathodoluminescence efficiency of YNbO4:Bi becomes lower than that of YNbO4. From the calculations of critical distance (R-C) of energy transfer and Huang-Rhys parameter (S-HR) of YNbO4:Bi, it is found that the energy transfer by a dipolar-type interaction is unlikely compared with that of a short-range interaction possible in the luminescence of YNbO4:Bi. Thus, it is believed that the luminescence property of YNbO4:Bi is mainly affected by the host lattice YNbO4 having self-luminescent NbO43- complex. By time-resolved spectroscopy, it is found that luminescence characteristics of activator Bi3+ in YNbO4:Bi shows a charge-transfer behavior. (C) 2001 American Institute of Physics.