Photoluminescence and thermal stability of Tb3+-doped K4SrSi3O9 phosphor with electron transition mechanisms

Abstract

Herein, we present a series of novel Tb3+-activated K4SrSi3O9 phosphors prepared by a simple solid phase reaction process. Owing to the characteristic 5D3/5D4-7FJ transitions of Tb3+, the Tb3+-activated K4SrSi3O9 phosphors possess a green emission under near-UV excitation and high thermal quenching temperature (>500 K). The temperature/concentration-dependent luminescence and decay properties of K4SrSi3O9:Tb3+ further elucidate the effects of cross relaxation, multiphonon relaxation and energy transfer processes on the luminescence of Tb3+ 5D3 and 5D4 levels. The electron population mechanism in the system is proposed in detail, which is expected to be generally applicable to all Tb3+-doped phosphors. Moreover, a near-UV white light-emitting diode (WLED) device with excellent CIE chromaticity coordinates (0.329, 0.320) is fabricated by using K4SrSi3O9:0.07Tb3+, demonstrating the potential applicability of K4SrSi3O9:Tb3+ for near-UV WLED.