Intense green-, red-emitting Tb3+, Tb3+/Bi3+-doped and Sm3+, Sm3+/La3+-doped Ca2Al2SiO7 phosphors

This paper focuses on an optical study of a Tb3+/Bi3+-doped and Sm3+/La3+- doped Ca2Al2SiO7 phosphor synthesized using combustion methods. Here, Ca2Al2SiO7:Sm3+ showed a red emission band under visible light excitation but, when it co-doped with La3+ ions, the emission intensity was further enhanced. Ca2Al2SiO7:Tb3+ shows the characteristic green emission band under near-ultraviolet light excitation wavelengths, co-doping with Bi3+ ions produced enhanced photoluminescence intensity with better colour tunable properties. The phosphor exhibited better phase purity and crystallinity, confirmed by X-ray diffraction. Binding energies of Ca(2p), Al(2p), Si(2p), O(1s) were studied using X-ray photoelectron spectroscopy. The reported phosphor may be a promising visible light excited red phosphor for light-emitting diodes and energy conversion devices.