Cobalt sulfide thin films: Chemical growth, reaction kinetics and microstructural analysis

Morphology reliance of cobalt sulfide thin films: A chemo-thermo-mechanical perception

“…Sharp reflection peaks highlight formation of polycrystalline CoS thin films with (Jaipurite) hexagonal crystal structure of space group P63/mmc. The observed values of lattice parameters, intensities of reflections and d-values have good consonance with the JCPD values (JCPDS: 03-065-0407) and earlier reports [8,11]. The existence of single reflection plane (5 1 1) at 2h = 59.32°suggested the presence of Co 3 O 4 impurity.…”

“…In general, growth by the chemical bath deposition proceeds at a moderate ion release rate and ions react with each other to form the nuclei either by spontaneous precipitation or significantly slowly in a highly alkaline medium [1][2][3][8][9][10][11]. Rigorous precipitation assures no film formation on the immersed substrates; alternatively, if the rate of precipitation is controlled, nuclei could get adequate time and chance to initiate the film formation process and hence layer growth onto the substrate surface.…”

“…For the synthesis, 10 triethanolamine (TEA) and 15 ml AR grade ammonia were added under constant vigorous stirring. To this mixture, 10 ml (1 M) thiourea was added at a constant rate.…”

“…In our case, the substrate holder design and its rotation allows excellent homogeneous automatic mechanical churning of the bulk solution that enhances the speed of arrival of the depositing ions on the substrate surface [1,6,[8][9][10][11]. At low speed (<50 rpm), the kinetic energy of the ions is quite low and only a few ions with enough kinetic energies will get deposited.…”

“…Cobalt sulfide is a technically important semiconductor material with many potential applications in optical filters, thermal sensors, solar selective coatings, PV -detectors including solar cells, optical waveguides and as a DMS material [5,8,[10][11][12]. Owing to its imperative role as magnetic semiconductor, many efforts have been dedicated to the morphology tailored growth of cobalt sulfides in the form of micro/nano-particles, wires, tubes and in thin film form.…”