Tuning Photophysical Properties of ZnO/TiO 2 Nanocomposite Thin Films by Controlling Anatase Titania Content

The influence of the anatase titania nanoparticles (TiO 2 NPs) content on the structural and optical properties of ZnO/TiO 2 nanocomposites (ZTNCs) was demonstrated. The solution blending method was employed to prepare the ZTNCs with various ratios prior to their deposition onto glass substrates to form thin films. The X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and transmission electron microscope (TEM) techniques revealed that the crystallite size, grain size, and particle size of each TiO 2 and ZnO NPs are almost equal. In addition to these techniques, Fourier transform infrared spectroscopy (FTIR) evidenced the homogeneity distribution of the TiO 2 within the ZnO NPs. The structural properties of the wurtzite ZnO NPs such as crystallite size, lattice strain, dislocation density, bond length ( L ) of Zn–O, energy density ( u ), lattice stress ( L S ), Young’s modulus, and unit cell volume ( V ), can be tuned by incorporation of anatase TiO 2 NPs in various content. Moreover, the optical properties of the wurtzite ZnO NPs such as absorbance, optical energy band gap ( E g ), energy gap tail ( E u ), steepness parameter ( σ ), and emission intensity can be tuned by incorporation of anatase TiO 2 NPs in various contents. The E g and σ of ZnO NPs were decreased to reach at 2.41 eV and 0.0051, respectively, whereas the E u was increased to 4.598 eV upon the increment content of TiO 2 NPs.