Surface state of Y3(Al,Ga)5O12:Tb phosphor under electron beam bombardment

► The chemical stability of Y3(Al,Ga)5O12:Tb phosphor was tested under prolonged electron beam exposure. ► The CL intensity of the Y3(Al,Ga)5O12:Tb stabilized after removal of the chemisorbed species. ► X-ray photoelectron spectroscopy results suggested electron-beam induced formation of new interleave oxide layers. ► The interleave oxide layers acted as a protective layer inhibiting further CL intensity degradation. ► A lowering in the work function due to the new surface layers lead to an increase in the number of electrons for CL excitation.