Spray Pyrolysed Nanostructured Gold-Doped Tin Oxide (Auto) Thin Films

Abstract

Nanostructured SnO₂ thin films were grown by the chemical spray pyrolysis (CSP) method. Homemade spray pyrolysis technique is employed to prepare thin films. SnO₂ is wide band gap semiconductor material whose film is deposited on glass substrate. A gold nanoparticle-doped tin oxide thin film (AuTO) was also prepared. UV-VIS (ultraviolet visible) spectroscopy and four-point probe analysis are done for optical and electrical analysis. UV-Visible absorption spectra show that the band gap of SnO₂ thin film is 3.78 eV and 3.82 eV for AuTO. Band gap of SnO₂ thin film can be tuned that it can be used in optical devices. The films have transmittance increases (to about 60%) and the absorbance decreases in the visible region of the electromagnetic spectrum. The electrical conductivity of the Tin Oxide is enhanced by functionalizing with the Gold nanoparticles. It is higher than that of the Tin oxide only; 0.77 x 10^-2 (Ohm cm)^-1 and 3.55 x 10^-2 (Ohm cm)^-1 for SnO₂ and AuTO respectively. These properties reveal that Tin Oxide doped with gold can actually be a good material for a transparent conducting oxide to be used in photovoltaic fabrication and in electronics.