Synthesis and Characterization of Stoichiometric Cobalt Monosulfide (CoS) Film by a Simple and Cost-Effective Screen-Printing Process

The electrical, morphological, and electro-optical behaviour of nanocrystalline cobalt monosulfide (CoS) film prepared on a clean glass substrate by screen-printing route and sintered at 250°C was studied. The nanocrystalline (with hexagonal) structure of the film was indexed by X-ray diffraction technique. The surface morphology of the film is very dense with no visible pinholes and cracks. EDX technique validates the growth of the nearly stoichiometric film. UV-VIS-DRS spectroscopy displays that the band gap (direct transition) energy (E_g) of 250°C sintered film was 1.45 eV. Photo-sensing behaviour of nanocrystalline CoS film was studied using current–voltage (I–V plot) characterization. I–V characteristics showed the change in the performance as when light is flashed on the device. p-Type conductivity for the film was observed via the hot probe technique. The accomplished results of CoS film were very awakening for electro-optical applications.