The role of Gd3+ in the luminescence of several Eu3+ activated borate phosphors was examined. The results showed that under 147 nm excitation, the photoluminescence of Eu3+ was improved with the incorporation of Gd3+ in the systems of YBO3:Eu3+ and YAl3(BO3)(4):Eu3+, while in the case of YAlO3: Eu3+ and CaYBO4: Eu3+, the luminescence of Eu3+ was decreased when Gd3+ was introduced into the host lattice. A simple energy band model according to the location of lanthanide energy levels relative to the conduction band and valence band of the host lattice was proposed to explain the phenomena. (c) 2006 The Electrochemical Society.