Lasing and thermoluminescence features of samarium/dysprosium co-doped barium-sulfur-telluro-borate glass embedded with pure gold nanoparticles

Abstract

Contemporary technological advancements drive the need for optimized Rare Earth Ions (REIs) host combination for lasing and thermoluminescence (TL) applications whereas the weak absorption cross-section of the REIs remains a challenge. Herein, a series of Sm3+ doped Barium-Sulfur-Telluro-Borate (BSTB) glass was prepared by the melt-quenching method. The role of Sm3+/Dy3+ co-doping and pure gold nanoparticles (AuNPs) embedment on the absorption cross-section of Sm3+ in the synthesized glasses was studied. The structural properties of the quenched glass samples were investigated using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) and Energy Dispersive X-ray (EDX) analyses. The Ultraviolet-Visible-Near-Infrared Spectroscopy (UV-Vis-NIR) spectra of the glasses exhibited characteristic absorption transitions of Sm3+. The photoluminescence (PL) spectra of the Sm3+-doped glasses showed four emission bands due to the 4G5/2?6H5/2, 4G5/2?6H7/2, 4G5/2?6H9/2 and 4G5/2?6H11/2 transitions in Sm3+ with varying intensities. The glass made with Sm2O3 content of 1 mol% revealed maximum PL intensity and this composition was chosen for co-doping with Dy2O3. Moreover, the obtained lasing attributes were also considerably affected due to codoping factor. High branching ratio and emission cross-section of 93.12% and 60.99?10-23 cm2 were obtained, respectively. Energy transfer mechanism from the Dy3+ to Sm3+ was confirmed from PL decay analysis. This energy transfer induced the shift in the CIE coordinates of the glasses from the reddish-orange zone towards the white region. The obtained Transmission Electron Microscope (TEM) images of the AuNPs embedded glasses showed the presence of irregularly shaped AuNPs with an average diameter of 29 nm. The AuNPs Surface Plasmon Resonance (SPR) bands were found at 670 and 718 nm. The SPR mediation stimulated the shift in the chromaticity coordinates from white to yellowish-orange zone. While the Sm3+- doped sample glasses did not show any TL response, the co-doped and AuNPs embedded glasses displayed TL response exhibiting a simple second-order glow curve with maximum intensity (Im) at 272 oC. The appearance of Im at hightemperature region indicated the stability of the glass against fading effect. The activation energies of the optimum glass obtained using the peak shape, initial rise, whole glow curve and computerized glow curve deconvolution methods were 1.021, 1.50, 1.537, and 1.369 eV, respectively. In conclusion, BSTBSmDyAu0.1 glass sample is best suited for lasing and thermoluminescence applications due to high branching ratio and emission cross-section approximately 55% and 111×10?23 cm2, respectively, coupled with the exhibited simple TL glow curve.