Influence of different process parameters on physical properties of fluorine dopes indium oxide thin films

Abstract

Fluorine-doped indium oxide films were prepared by the spray pyrolysis technique. The physical properties of these films were investigated with respect to various process parameters, namely variation of dopant concentration (in the solution), deposition temperature (T _s), carrier gas (air) flow rate and the thickness of the film. The best films had a Hall mobility of the order of 28 cm²V⁻¹ s⁻¹ and a carrier density of 2.7 × 10²⁰ cm⁻³. These films were deposited at T _s=425 °C at an air flow rate of 71 min⁻¹ for an atomic ratio of fluorine to indium of 72%. The electrical resistivity of these films was of the order of 10⁻⁴ Ω cm and the average transmission in the visible range was found to be 80–90%. The films were polycrystalline, n-type semiconductors with [400] as a preferred orientation. The preferred orientation changes from [400] to [222] depending upon the process parameters.