| Summary: | It has been demonstrated that lyotropic liquid crystal templates (LLCT) with mesoporous structures can be used during electrodeposition of thin films to produce films with a mesoporous structure transferred from the LLCT. Here we report the electrodeposition of mesoporous bismuth telluride (Bi2Te3) films from hexagonal structured LLCTs formed from mixtures of Brij®C10 and electrolyte solution in ratios of (55:45, 50:50, 45:55). The introduction of a mesoporous nanostructure to the bismuth telluride films should improve the thermoelectric properties of the material. Optimisation of the electrolyte solutions has been carried out, studying the effects of using the metals bismuth (Bi) and tellurium (Te) and the metal salts bismuth citrate (C6H5BiO7), bismuth nitrate pentahydrate (Bi(NO3)3∙5H2O and tellurium dioxide (TeO2) dissolved in nitric acid (HNO3) or citric acid (C6H8O7) in different ratios and concentrations. The addition of a buffer solution made of citric acid and sodium citrate (C6H5Na3O7) has also been investigated. The lyotropic liquid crystal phases present for mixtures containing different concentrations of Brij®C10 and these electrolyte solutions has been looked at, including the production of phase diagrams. The liquid crystal template mixtures have been characterised using a polarised optical microscope (POM) and wide and small angle X-ray Diffraction (XRD) and Cyclic Voltammetry (CV). The deposited thin films have been characterised using wide and small angle XRD, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDX), confirming that hexagonally nanostructured thin films in the (110) orientation with a composition close to Bi2Te3 have been produced.
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