Composition variation in optimized solid state reaction conditions has been done to achieve intense green emission in YTbxBO3 phosphor under UV and VUV (147nm resonant Xe*, 172nm Xe-2* excimer band) excitation. Inert interface layer created by fabricating a shell of silica nanoparticles over individual phosphor grain protected the phosphor surface from deterioration and oxidation of luminescent ion (Tb3+) thus completely arresting phosphor degradation. At optimum Tb content of 20 mol%, integrated photoluminescence intensity of developed YTbxBO3 phosphor is four times higher than commercial green YBT. With short decay time of 4 ms, YTbxBO3 core-nano silica shell green emitting phosphor has great application potential in PDP panel and phosphor coated Xe lamps. (C) 2011 Elsevier B.V. All rights reserved.