Spectrographic analysis of zinc-sulfate-magnesium-phosphate glass containing neodymium ions: Impact of silver–gold nanoparticles plasmonic coupling

Abstract

Ascertaining plasmonic interaction induced by silver (Ag) and gold (Au) nanoparticles (NPs) in the amorphous system can open a new direction in photonics. In this outlook, various contents of Ag and Au NPs were incorporated into neodymium ions (Nd3+)-doped zinc-sulfate-magnesium-phosphate glasses via the melt-quenching method. The impact of Ag–Au plasmonic coupling on the structures and spectroscopic traits of the prepared glasses were evaluated. As-quenched samples were analyzed using XRD, HRTEM, Raman, absorption and photoluminescence (PL) spectrometer. The Judd-Ofelt (JO) theory was used to evaluate the spectroscopic quality and stimulated emission cross-section of the glasses. HRTEM micrographs verified the existence of Au and Ag NPs in the glass matrix with a mean size ranged 4.47–7.03 nm. The observed thirteen absorption bands centered around 326, 352, 430, 459, 473, 512, 52, 581, 627, 681, 744, 801, and 875 nm were corresponding to electronic transitions from the ground state (4I9/2) to the excited states of 4D7/2, 2D1/2+4D3/2+4D5/2, 2P1/2, 4G11/2, 2D3/2+2P3/2+2G9/2, 4G9/2+2K13/2, 4G7/2, 4G5/2+2G7/2, 2H11/2, 4F9/2, 4F7/2+4S3/2, 4F5/2+2H9/2 and 4F3/2 in Nd3+. Two surface plasmon resonance (SPR) bands assigned to Ag and Au NPs were probed at 442 nm and 503 nm. The addition of Au NPs causes the SPR band of Ag NPs to be red-shifted. The NIR PL bands at 878 nm, 1050 nm and 1322 nm were due to the 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions, respectively. The PMZ1.5Nd0.5Ag0·1Au glass disclosed the highest bandwidth gain of 6.92, 17.05 and 9.10 ( × 10−23 cm3) corresponding to the 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions. It was shown that the PL intensity of the studied glasses could be modified by varying Ag and Au NPs contents. The Ag–Au NPs plasmonic coupling inclusion inside the glass can be beneficial to develop versatile optical materials.