Research on a new Tm3+-doped Ca3La2W2O12 blue-emitting phosphor for plant-cultivation LEDs

Abstract

Recently, rare-earth doped phosphors have been newly developed and applied in phosphor-converted light-emitting diodes (pc-LEDs). A Tm³⁺-activated tungstate Ca₃La₂W₂O₁₂ blue-emitting phosphor was synthesized by a high-temperature solid-state reaction. The phase purity, crystallinity, and surface morphology of the Ca₃La₂W₂O₁₂: xTm³⁺ (x = 0.2%-15% mol) phosphors were characterized by X-ray powder diffraction. Under 358 nm excitation, the phosphor can exhibit narrow blue-light emission at 460 nm due to the transition ¹G₄ →3 H₆ of Tm³⁺. The critical energy transfer distance and optimal doping concentration of Tm³⁺ ions are 16.92 Å and 0.10 mol, respectively. The Commission International del’Eclairage (CIE) chromaticity coordinates of Ca₃La₂W₂O₁₂:0.10Tm³⁺ are (0.1447, 0.0492) with a high color purity 95.8%. The results suggested Ca₃La₂W₂O₁₂:Tm³⁺ phosphors can be promising blue-emitting components for LED applications.