The High Impact of Solution Flow Rate on Optical Properties of TiO₂ Thin Layers for Optoelectronic Applications

Abstract

Abstract The semiconductor's realization is a very significant stage of optoelectronics devices. In this work, an elaboration of the TiO 2 semiconductor is made with various solution flow rates via spray pyrolysis. The structural and optical properties of pure TiO 2 are investigated with several characterization techniques which include: X‐ray diffraction (XRD), Raman spectroscopy, and UV–vis spectrophotometry. The XRD of elaborated TiO 2 layers exhibits nanocrystalline nature with a preferential orientation at the (101), a unique phase of anatase TiO 2 . The apparition of vibration modes in Raman spectra confirms the TiO 2 formation with a single phase. The produced TiO 2 has an optical transmission varying from 90% to 70% in the visible wavelength. The energy band gaps are 3.42, 3.32, and 3.28 eV for the TiO 2 elaborated at 1, 1.5, and 2 mL min −1 , respectively which prove the semiconducting properties of TiO 2 . All other optical parameters such as refractive index (n), extinction coefficient (k), and dielectric constant (ε r , ε i ) vary with the variation of solution flow rate. These investigations discover that the properties of TiO 2 layers can be adjusted by solution flow rate. It seems that the process of spray pyrolysis provides a facile way to control the quality of TiO 2 thin layers.