Microstructural, optical and dielectric variations in SnO2 nanoparticles synthesized via surfactant-assisted sol–gel route

SnO2 nanoparticles are synthesized via sol–gel method in the presence of two surfactants isopropyl alcohol (IPA) and lauryl alcohol (LA). The synthesized nanoparticles are characterized for the microstructural features by X-ray powder diffraction (XRD) and field-emission scanning electron micrograph. To resolve the presence of defect-related oxygen vacancies and trapped states, optical studies such as UV–visible absorbance and Raman spectra have been carried out. The charge transport in the material is analysed by studying the AC electrical conduction. The deposited tetragonal rutile-phased SnO2 nanoparticles are benefited by morphological modifications along with crystallite size reduction (from 21.5 to 15.1 nm) and an increase in dislocation density on changeover from LA to IPA in the precursor. Also, a preferential orientation of (112) plane is observed for the LA-assisted sample. The bandgap of the particles prepared via LA addition is found to be considerably larger (3.71 eV) than that of IPA-assisted sample (3.44 eV). A detailed study of Raman spectra elucidates the presence of defects. The AC conductivity analysis reveals that the mobility of charge carriers is higher in LA-assisted sample, which substantiates the findings from microstructural and optical studies.