New orange-red emitting phosphor La3NbO7:Eu3+ under blue excitation

Abstract

A new orange-red emitting phosphor La3−xNbO7:xEu3+ (x=0.05, 0.10, 0.15, 0.20) was prepared by a solidstate reaction route. Studies revealed the incorporation of Eu3+ into two differently coordinated La3+ sites, thereby favoring the multiband emission. Absorbance, photoluminescence excitation, emission and concentration dependence of Eu3+ luminescence were investigated. The results indicate that the host exhibited high absorption in the UV region which enabled effective energy transfer from NbO6 7− groups to Eu3+ excitation levels. Intense orange red emissions were observed under near UV (394 nm) and blue (464 nm)excitations nicely matching with the output wavelengths of UV and blue LED chips. The emission intensity of the phosphor under blue excitation is nearly twice that of the phosphor under near UV irradiation. Thus the intense orange red emitting host sensitized phosphor could be a promising phosphor candidate in generating white light combined with the blue chip