Silver Nanoparticle Enhanced Luminescence of Samarium in Magnesium Tellurite Glass: Energy Transfer Effect

Abstract

Improving the optical properties of rare-earth-doped inorganic glasses embedded with metallic nanoparticles (NPs) is a constant challenge in photonics. The main issue being addressed is optimising the NPs concentration in order to meet the requirements for  lasing glasses. Glass samples with composition 88.6TeO₂-10MgO-_xSm₂O₃-(1.4-x)AgCl for 0.2≤x≤1.0 in mol% were prepared using melt quenching technique. X-ray diffraction patterns demonstrate a broad hump pattern as a verification of the amorphous nature of the glasses sample. The transmission Electron Microscope images show the existence of silver nanoparticles (Ag NPs) in the spherical shape. Down-conversion emission spectra were carried out under an excitation wavelength of 554 nm, exhibiting a single emission 
band located in the range of 703 nm to 724 nm depending on composition and corresponding to the ⁴G_5/2→⁶H_11/2 transition. The observed enhancement in PL intensity is reflected in the energy transfer from Ag NPs to Sm³⁺ and local field enhancement around Sm³⁺ ions. The enhancement mechanism is further correlated to Q-factor calculation to investigate heat dissipated during non-radiative emission. The result of the Q-factor was supported by the decrement and enhancement in the intensity of PL emission.  Our findings are highly beneficial for the fabrication of solid-state laser, optical and photonic devices.