Photoluminescence characteristics of a novel orange red-emitting Eu3+ doped K3Ca2(SO4)3F phosphor for W-LED

Abstract

The present work reported the synthesis of Eu³⁺-activated K₃Ca₂(SO₄)₃F sulfate-based phosphors via a solid-state reaction method (SSR). The crystal structure of as-synthesized phosphor was studied by XRD analysis. The PL and PLE spectrum were investigated using photoluminescence spectroscopy. The PL excitation spectrum monitored at 616 nm shows sharp line excitation peaks at 395 nm,466 nm and 535 nm, attributes to ⁷F₀→ ⁵L_6, ⁷F₀→ ⁵D_2, and ⁷F₀→ ⁵D₁ transitions respectively. The PL spectrum under UV excitation of 395 nm exhibits emission in the red region centered at 592 nm and 616 nm, corresponding to ⁵D₀→ ⁷F_1, and ⁵D₀→ ⁷F₂ transitions of Eu³⁺ ions in the host. The CIE coordinates confirm the emission in the orange-red region positioned at (0.6824, 0.3175) with color purity of 97.37% and CCT 3872.2 K. The obtained outcome reveals that the reported K₃Ca₂(SO₄)₃F: Eu³⁺ phosphor is the best candidate as UV excitable orange-red emitting phosphor for w-LEDs.