Green Emission of Erbium Doped SYW Phosphors for Optical Thermometry And Solid‐State Lighting
Sheetal Kumari, A.S. Rao, Ravindra Kumar Sinha
Abstract
Abstract A series of Er 3+ ions doped Sr 9 Y 2 W 4 O 24 (SYW) phosphors have been synthesised using solid‐state reaction technique. For optical thermometry and solid state lighting applications, the crystal structure, morphological, and luminescence features of the SYW : Er 3+ phosphors were explored. X‐ray diffraction (XRD) reveal that synthesized phosphors having single phase with a tetragonal crystal structure and I4 1 /a space group. Scanning electron microscopy (SEM) was used to examine the morphological behaviour and presence of composition elements. The optical bandgap of the phosphor was evaluated using UV‐Vis diffuse reflection spectra (DRS). The photoluminescence (PL) emission spectra were captured under 380 nm excitation, and the peak with the maximum intensity was identified at 563 nm ascribed to transition 4 S 3/2 → 4 I 15/2 , that emits green color in visible region. The temperature dependent PL (TD‐PL) spectra show that SYW phosphor is substantially more thermally stable, having thermal activation energy of about 0.247 eV. Additionally, the fluorescence intensity ratio (FIR) was used to study the optical sensing characteristics of the thermal quenching transitions ( 2 H 11/2 , 4 S 3/2 ) with maximum relative sensitivity (S R ) and an absolute sensitivity (S A ) being 1.33 % K −1 and 0.307 % K −1 , respectively. All of the aforementioned findings demonstrate that SYW : Er 3+ ions doped phosphors have potential for optical thermometry and other photonic devices.