Growth and characterization of screen printed TiO2–CuO thick films for optoelectronic applications

Abstract

We herein report, the deposition of pure and CuO doped TiO2 thick films on glass slides by a cost effective screen printing process, which were then sintered to obtain desired stochiometric composition. Different analytical approaches were used to reveal the precise structural, morphological, optical and electrical characteristics information of pure TiO2 and TiO2–CuO thick films. X-ray diffraction (XRD) patterns exhibit the formation anatase phase of TiO2 and monoclinic phase of CuO. Raman spectra show four TiO2 anatase phase modes only in 100–800 cm−1 region. Infrared (IR) transmittance spectra of these samples recorded in 4000–400 cm−1 region also showed weak, very weak and medium intensity stretching and bending modes of O–Ti–O and Ti–O–Ti bond groups of TiO2 only in 700–400 cm−1 region which further supported the formation of TiO2 anatase phase only. Scanning electron microscopy (SEM) images indicate porous surfaces morphology, irregular shaped as well as size polygonal and spherical shaped particles with tendency to form aggregates along with the EDS analysis that confirms proper composition of the films. The optical band gap energies were derived from diffused reflectance spectroscopy and photoluminescence (PL) spectra. They showed a red shift in peak positions which caused reduction in band gap energy. The CIE diagram clearly depicted blue-green and white emissions. I–V characteristics has been used for calculation of the diode parameters such as ideality factor (n) and barrier height (Φb). The extracted results such as band gap, particle size and electrical parameters suggest that the TiO2–CuO thick films can be used in photovoltaic applications.