Europium luminescence in silver and gold nanoparticles co-embedded phosphate glasses: judd-ofelt calculation

Abstract

Some europium ions (Eu3+) activated magnesium-zinc-sulfophosphate glasses with the silver (Ag) and gold (Au) nanoparticles (NPs) co-embedment were prepared via the melt-quenching method. The as-prepared samples were characterised using different analytical techniques to determine the effect of various Au NPs contents (0.05, 0.10, 0.15, 0.20, 0.25, and 0.30 g) on their spectroscopic characteristics. Furthermore, the Judd-Ofelt theory was used to evaluate the intensity parameters and radiative properties of the glasses. These glasses showed very high optical gain (in the range of 5.10 × 10−25 to 15.87 × 10−25 cm2 s−1) and branching ratio (from 8.27 to 61.6%). The glass prepared with Au NPs of 0.25 g revealed the highest optical gain (15.7 × 10−25 cm2 s−1) and gain bandwidth (9.55 × 10−22 cm2) for the 5D0→7F2 transition. The observed significant increase in the stimulated emission cross-section of the glasses indicated their prospect towards the photonic device fabrication. The achieved improvement in the photoluminescence emission intensity for the 5D0→7F2 transition was largely credited to the energy transfer between the Eu3+ and NPs inside the glasses. The high colour purity (for red colour coordinate) of the glasses obtained from the CIE chromaticity diagram suggested their potential for the development of efficient red laser.