Abstract

Tin oxide nanoparticles (SnO2 NPs), both pure and doped with Group VI (G6) metal ions (Cr+3, Mo+5, and W+6), were synthesized using pulsed laser ablation in liquid. This study aimed to investigate the effect of G6 doping on the electronic properties of SnO2 NPs, with an emphasis on enhancing their photoluminescence for optoelectronic applications. Transmission electron microscopy revealed well-crystallized samples with diameters of 3-6 nm, indicating quantum-confinement effects. The optical band gap, determined by UV-Vis spectroscopy, was reduced from 5.1 eV (undoped) to 4.9 eV (Cr-doped) due to defect states, while increasing to 5.3 eV and 5.7 eV for Mo- and W-doped SnO2, respectively, due to the Moss-Burstein effect. The photoluminescence spectra exhibited a redshift, with strong red emission around 700 nm, which was up to 90 % more intense than that of the undoped SnO2. This enhancement was attributed to the 2E -> 4A2 transition and increased defect states.