Luminescence of rare earth borosilicates with the stillwellite and related structures

By hydrothermal reactions it was possible to prepare well-crystallized borosilicates of composition La1 − x − yLnxLn′yBSiO5 with the trigonal stillwellite structure. Ln = Eu3+ and Tb3+ produce compounds with only weak luminescence. Compounds with Ln = Ce3+ are strong UV phosphors with peak intensity at x = 0.08 and abrupt concentration quenching at x = 0.10. Compounds with Ln = Ce3+ and Ln′ = Tb3+ exhibit effective Ce3+ → Tb3+ coactivation and strong green luminescence. This family of borosilicates appears to be useful phosphor hosts, aside from the necessity of non-traditional synthesis.