Characteristics of TiO2-Cu thin films deposited using electrospray technique

Abstract

In this current research, TiO2 thin films were deposited on the cleaning p-type silicon substrates via using electrospray technique. Various deposition electric potentials were utilised within the scope of 0–5 kV. To understand potential factors affecting TiO2-Cu thin films, the structural, morphological, optical characteristics and the surface chemical composition were explored. The X-ray diffraction peaks showed that all TiO2-Cu samples were composed of multiphase according to the preparation conditions. The prepared films were characterised by the emergence of multiple phases of Ti-O, Cu-O, and Cu-Ti-O systems. Both particle size and porosity of films were affected by the applied electrical potential, where the size was directly proportional to the potential (12.6, 7.6, and 16.3 nm) with free, 3.6 and 4.5 kV respectively, while dropped with 5 kV to 7.2 nm. The porosity behaved similarly to the size distribution as a function of electric potential, the maximum value of it was 53.55% with 4.5 kV. Also, the thickness of the prepared films was directly proportional to the increased which increased from 0.147 µm with free potential to 3.5 µm with 5 kV. PL spectroscopy was used to analyse the optical properties in order to confirm optical absorption in the visible light field. All prepared films showed highest peaks between 342–344 nm with change in both width and intensity. The results provide insights into the enhanced properties of TiO2-Cu thin films under different electric potential. According to these properties, the samples at (4.5 kV and 5 kV) are expected to be appropriate to use in gas sensor and bio-sensing applications.