Sol-gel Spin-Coated Y-doped SnO2 Nanostructured Thin Films for Various Optoelectronic Device Applications

The effect of various concentrations of Y-doped SnO2 thin films (Y: SnO2) on structural, optical, and electrical properties was investigated. XRD showed the polycrystalline tetragonal structure of all the films. SEM analysis showed homogenous growth of the films with spherical structure. XPS revealed the oxidation states of Sn, Y, and O, also it provides the presence of oxygen vacancies in Y: SnO2 films. The UV-visible spectrometer studies showed that all the films were above 76% of optical transmittance in the visible region. The optical band gap energy was found to be 3.91 eV for pure SnO2, whereas Y: SnO2 films have shown a decrease of band gap with Y content and reached down to 3.74 eV in 5 at% Y: SnO2 film. The 3 at% Y: SnO2 film showed the lowest sheet resistance (R-sh) of 34.2 Omega/Sq and the highest figure of merit (phi) of 3.55 x 10(-3) Omega(-1) among the others.