Cathodoluminescence Change of YNbO₄:Bi Phosphor after Acid Treatment

Abstract

The reason for the cathodoluminescence (CL) change of YNbO 4 :Bi after acid treatment is determined. It is observed that after acid treatment, the CL intensity of YNbO 4 :Bi decreased to a value below that of the untreated one at excitation energies lower than 1 keV. However, YNbO 4 :Bi was brighter than the untreated one at an excitation energy of 1 keV or higher. Meanwhile, ZnGa 2 O 4 was compared with YNbO 4 :Bi in terms of luminescence properties. After acid treatment, ZnGa 2 O 4 showed the same trend as YNbO 4 :Bi at excitation energies lower than 1 keV. However, the luminescence intensity of ZnGa 2 O 4 did not increase at an excitation energy of 1 keV or higher. It was found that surface modification using an acid increases the luminescence efficiency of YNbO 4 :Bi by realizing stoichiometric composition at the phosphor surface.