Research On Solvothermal Synthesis And Characterization Of CuInSe₂ Particles

For the environmental protection and energy exhaustion, the search for renewable, cheap and clean energy source has been an essential problem for humankind. Solar energy is a kind of source of energy with reproducible and no effect on environment. Development on photovoltaic conversion semiconductor materials has been a focus for researchers. CuInSe₂ (short for CIS) is a highly promising semiconductor material for thin film solar cells, which holds optimum energy band gap, extraordinarily high absorption coefficient and highest photovoltaic conversion efficiency. The printing method is available for preparation of large-area and well-proportioned CIS films. In this process preparation of CIS nanopartcles with suitable morphology and well-proportioned stoichiometric compositions would be very important.In this thesis, CIS nano-/microstructures have been synthesized via solvothermal routes. The as-prepared products was investigated analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible-near infrared spectrum (UV-Vis-NIR). The main contents are as follows:1. CIS was synthesized by anhydrous ethylenediamine. Research on the relationship of various reactants, reaction time and temperature, addition of surfactants and pre-treatment of reactants with composition and morphology of as-prepared samples. The result shows the solid-liquid contact area of reactants and solvent is essential factor on the reaction rates; the products are tendential to develop to 1-D and 2-D morphology; the reason of unequal morphology is inadequate dispersion degree of reactants. Reaction effect was also analyzed.2. CIS nanoparticles ware also synthesized when water as solvents and ethylenediamine as coordination agent. The dispersion degree of reactants was improved when water solvent was induced. The impact on composition and morphology of as-prepared samples by various reactants, reaction time and temperature was investigated. The result shows particles scale would be smaller when more volume of water was induced to the solvents. On the other hand, reduce of water may result in hydrolyze of In³⁺ and Se difficult to ionization. It's essential to increase the reaction time and elevate the reaction temperature. for the sake of making up the disadvantage influence of water solvents to the reaction system. A suitable proportion of hybrid solvents is crucial to synthesize spherical pure nanoparticles with suitable morphology.