Electrochemical Synthesis and Charge Transport Properties of CdS Nanocrystalline Thin Films with a Conifer-like Structure

Well-defined intersectional CdS nanocrystalline thin films with a conifer-like morphology were synthesized by a facile electrochemical process. The morphology, structure, and phase composition of CdS nanostructures were examined by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and energy-dispersive X-ray spectroscopy. The electrochemical deposition conditions influencing the synthesis of these conifer-like CdS nanocrystals, such as deposition temperature, deposition time, current density, and concentrations of the precursors, were studied systematically. The orientation-transformation mechanism of the growth of conifer-like CdS nanocrystals was proposed based on the results, which is beneficial for the shape-controlled synthesis of other shaped nanostructures. The charge transport properties of these thin films before and after annealing treatment were also studied via the space-charge-limited conduction model, from which the total density of trapping states and the electron mobility in CdS nanocrystalline thin films were estimated.