Synthesis, characterization and interpretation of screen-printed nanocrystalline CdO thick film for optoelectronic applications

Abstract

The transparent conductive oxide CdO thick films are prepared by screen printing method followed by sintering route. The structural, optical and electrical properties of as-grown films are characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR), ultraviolet–visible (UV–VIS) and DC conductivity measurement techniques. XRD, SEM and AFM studies reveal that the film deposited is polycrystalline, single phase and granular in nature. The crystallite size from XRD pattern’s most strong (111) peak calculated using Debye–Scherrer’s formula is 30 nm. IR transmission spectrum exhibits Cd–O stretching and bending mode peaks at 831 and 672 cm−1, respectively. Electrical properties were characterized by two-probe measurement in the temperature range between 300 and 400 K. Optical transmission spectroscopy and DC conductivity measurements have revealed the semiconducting nature of this film with direct band gap energy 2.53 and 0.29 eV activation energy and dc conductivity 4.5 × 10−7 (’Ωcm) −1.