Structural, optical and electrical characterization of nanocrystalline CdO films for device applications

Nanocrystalline CdO films were prepared onto glass substrate by employing an inexpensive, simple screen-printing method. Optimum conditions for preparing good quality screen-printed films were subsequently obtained. The grown films were characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), scanning electron microscopy (SEM), UV–vis spectctroscopy and DC electrical resistivity measurement in vacuum by a two probe method. The XRD analysis reveals that the films were polycrystalline in nature, exhibiting cubic structure with preferential orientation of grains along (1 1 1) plane. EDAX analysis confirmed the presence of Cd and O element with some additional impurities. Scanning electron microscopy studies show that prepared films exhibited cauliflower like structures. Direct type of transition of band gap was confirmed by reflection spectra occurring at 2.5 eV. The DC electrical resistivity measurement reveals that the films were semiconducting in nature with activation energy ∼0.270 eV. Type of charge carriers of films were determined by Hall effect measurement.