Energy transfer mechanism of Ce3+ → Tb3+ → Eu3+ in Ba9Y2Si6O24

Ba9Y2Si6O24 phosphors doped with cerium (Ce3+)-terbium (Tb3+)-europium (Eu3+) were fabricated using solid phase sintering technique. The crystallinity and luminescence characteristics of rare earth ions doped Ba9Y2Si6O24 phosphors were characterized. Energy transfers (ETs) between cerium-terbium-europium ions in Ba9Y2Si6O24 were investigated. We found that ETs between cerium-terbium and terbium-europium occurred but ET of Ce3+ → Eu3+ was prohibited. However, it can be generated by terbium chain. Therefore, red emission corresponding to europium was obtained under UV light excitation and it was enhanced by energy transfers from cerium to terbium and then to europium.