Enhanced up- and down-conversion luminescence from Dy3+-Sm3+ co-doped B2O3-SrCO3-TeO2-Al2O3-MgO glass hosts: effects of CuO nanoparticles embedment

Abstract

In the up-conversion nonlinear optical process, the absorption of lower energy photons causes the emission of photons at higher energy due to various mechanisms like sequential optical excitation, energy transfer, and nonlinear light-matter interaction processes. Improving the up- and down-conversion luminescence of different lanthanide-doped glasses via metallic nanoparticle embedment remains challenging. There has been no clear understanding of how copper oxide nanoparticles (CuONps) affect the spectroscopic properties of Dysprosium-Samarium ions (Dy3+-Sm3+)-co-doped glasses. Thus, new CuONps-infused strontium-telluro-aluminum-magnesium-borate glass samples were prepared using the standard melt-quenching technique with Dy3+-Sm3+ co-doping. X-ray diffraction (XRD) analysis confirmed the samples' glassy nature. High-resolution transmission electron microscopy (HRTEM) provided the orientation and size distribution of the embedded nanoparticles in the glass hosts. The downconversion luminescence emission (at 350 nm excitation) corresponds to 4F9/2 → 6H15/24F9/2 → 6H13/2, and 4F9/2 → 6H11/2 transitions in Dy3+. Judd-Ofelt calculations for the CuONps embedded sample showed significant radiative properties. A branching ratio of 79.6% was attained. The upconversion luminescence emission (at 896 nm excitation) bands corresponded to 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions for the Dy3+-doped glasses. In addition, an intense peak due to the 4G5/2 → 6H7/2 transition in Sm3+ was observed in the co-doped glasses. It was determined that the increased up-conversion luminescence was related to localized surface plasmon resonance, energy transfer, and local field enhancements caused by CuONps inclusion. It was confirmed that excited state absorption and energy transfer mechanisms were involved in the up-conversion luminescence. Synthesized glasses may be helpful for upconversion displays, optical data storage, and solid-state lasers.