Selection of Gd2(WO4)3:Tb3+ for inproving color deviation in white light-emitting diodes

Abstract

This study successfully using the hydrothermal technique to synthesize Gd₂(WO₄)₃:Tb³⁺ phosphors when subjected to calcination under the temperature of 900°C. Here are some aspects that were thoroughly examined: the crystal formation, photoluminescence, photoluminescence excitation, as well as fluorescent degradation for the samples. The (Gd_2-xTb_x)(WO₄)₃ (x=0.01-0.15) phosphors exhibit a bright discharge of green under 547 nm (⁵D₄→⁷F₅ shift for Tb³⁺) when excited at 270 nm (⁴f₈→⁴f₇⁵d₁ shift for Tb³⁺). Because of the exchange interaction between Tb³⁺, the quenching concentration was determined to be around 10%. The addition of Tb³⁺ had no effect on the (Gd_2-xTb_x)(WO₄)₃ phosphors' CIE chromaticity coordinates (~0.33±0.02, ~0.60±0.02) or color temperatures (~5542 K). Nevertheless, when the Tb³⁺ content increased, the fluorescence lifespan for 547 nm emission reduced due to energy transfer between Tb³⁺. The strong green emission from Gd₂(WO₄)₃:Tb³⁺ phosphors is a potential element for WLEDs and display areas.