Luminescent properties of Cu+/Sn2+-activated aluminophosphate glass

Abstract

A robust aluminophosphate glass matrix containing substantial amounts of Cu2O and SnO has been prepared by the melt-quenching technique, and the luminescent properties have been assessed. The as-prepared material exhibits tunable luminescence by variation of excitation wavelength, in connection with the distinct excitation/emission properties of Cu+ ions and twofold-coordinated Sn centers in the host. Under excitation of both Cu+ and Sn species at 300nm, the co-doped material exhibits a bright whitish luminescence, whereas excitation at 360nm produces an intense orange emission arising merely from Cu+ ions. Thus, white light generation is deemed realizable by combination of cool-bluish emission intrinsic to Sn centers with the warm-orange emission from Cu+ ions. The optical properties of the material after heat treatment have been also investigated. Results indicate the chemical reduction of ionic copper via Sn2+ ultimately producing Cu nanoparticles as evidenced by the surface plasmon resonance. Consequently, the excitation-wavelength dependent photoluminescence bands appear suppressed in relation to Cu+ basically and show a dip attributed to light reabsorption by the plasmonic Cu particles.