Comparative study on photoluminescence of amorphous and nano-crystalline YAG:Tb phosphors prepared by a combustion method

► Amorphous YAG:Tb phosphor samples can be obtained via a facile sol-gel combustion method. ► The photoluminescence intensity decreases under 250 nm excitation with increasing the crystallinity. ► The strongest intensity of samples annealed at 800 °C could be obtained with 10% Tb doping. ► Red-shifts derive from the deformation of inter-atomic distances within the Tb3+ coordination polyhedron. ► A matrix consisting of various amorphous YAG:Tb contents can be applied for an advanced anti-bogus label.