Tuning the Langasite, La3SbZn3Si2O14, towards white light emission: synthesis, structure, SHG and photoluminescence studies

Abstract

A series of single-phase color-tunable Langasite, La₃SbZn₃Si₂O₁₄:RE³⁺ (RE = Eu, Tb, and Tm) phosphors have been prepared and characterized employing X-ray diffraction (XRD), Raman, and photoluminescence (PL) studies. The substituted compounds, La₃SbZn₃Si₂O₁₄:Eu³⁺, La₃SbZn₃Si₂O₁₄:Tb³⁺ and La₃SbZn₃Si₂O₁₄:Tm³⁺ exhibit the characteristic emissions of Eu³⁺ (red), Tb³⁺ (green) and Tm³⁺ (blue), respectively. By carefully adjusting the concentration of Eu³⁺ ions in the La₃SbZn₃Si₂O₁₄:1% Tm³⁺, 2% Tb³⁺, x% Eu³⁺ system, we achieved a white emission with a reasonable quantum yield. The compounds are found to be SHG (second-harmonic generation) active with the highest values of 3.6 × KDP (potassium dihydrogen phosphate). In addition, the compounds exhibit reasonable dielectric constants with low loss. The present study demonstrates the color tunability of the Langasite family of compounds and establishes it as an adaptable structure.