A potential high color purity and thermally stable red-emitting phosphor based on Tb3+ and Eu3+ co-doped sodium yttrium borate: Synthesis and luminescence spectroscopic characterization

Abstract

A series of Tb3+ and Eu3+ single- and co-doped Na3Y(BO3)2 (NYB) was prepared by the solid-state reaction method and characterized their structural, thermal and photoluminescence properties while focusing on the development of efficient narrow-band red-emitting phosphors for near-UV chip-based phosphor-converted white LED (pc-WLED). Luminescence spectroscopic and decay kinetics studies of NYB:Tb3+, Eu3+ sample series demonstrated an occurrence of energy transfer from Tb3+ to Eu3+ with its efficiency dependent on Eu3+ concentration and temperature. The highest quantum yield of 83.5% was observed for NYB:5.0%Tb3+, 40%Eu3+ composition with excellent thermal stability. The phosphor was finally tested for the use as a red phosphor component in pc-WLED, which demonstrated a high color rendering index of 84.7. The phosphor is a good modelling composition for the development of wider family of narrow-band red-emitting phosphors based on Tb3+/Eu3+ co-doped inorganic oxides for application in pc-WLED.