| Inorganic semiconductor material, also called polymer resin composite material, notonly has the properties of polymer resin material with excellent adhesion, film formingpolymer and flexibility, but also has the optoelectronic properties and thermal stability ofinorganic semiconductor material. The thin-film solar cells made of this kind of compositematerial could meet the the easy processing, stable and efficient requirements, which has awide application prospect. Therefore this thesis, taking PVB resin, CuFeS2as the researchobject, aims at the preparation of the easy processing, cheap, high thermal stability andexcellent optical performance of PVB/CuFeS2photoelectric composite materials.First, with the method of hot solvent, CuFeS2nanocrystals could be made bycontrolling the different temperature and concentration. The experimental results show thatthe performance of synthetic changes with the changing concentration of ferrous sulfate.When the concentration of ferrous sulfate is15ml, the synthetic turns out to be flakycrystal with better particle morphology and high crystallinity. Apart from uniformdispersion, it has the highest light absorption and good conductivity. Here the resistivity is24.7(Ω·m), and the band width is0.89eV. Also the temperature has a obvious effect on thecapabilities of the crystal. When the temperature rose up to210℃, the product had lessimpure peaks and the peaks were narrow and sharp. Now it presented the most obviousflaky crystal, piling up close together with good electrical conductivity and the strongestabsorption strength. Meanwhile there exists an obvious red shift of absorption peak, andthe band width is0.76eV close to that of pure CuFeS2nanometer grain.Secondly, it tries to change the morphology and structure of CuFeS2nanocrystals withthe method of doping with sodium chloride in order to get the best crystal texture. With thechanging doping amount, crystal morphology and structure also change. In this way, thecrystal morphology gets better than before. Here the optimum value of doping is0.1g. Itturned out to be columnar crystals with the strongest crystallinity, meanwhile, crystalmorphology is neat and particle is of uniform size. The average grain size is of44.2nmwith good light absorption. The addition of CTAB didn’t change the crystal structure.When the optimum adding amount is0.3g,29.5°, it presents the highest diffractionintensity, and the products are of the best dispersion and uniform particle size. Also theconductivity and optical absorption performance are the optimal.Finally, with the action of PVB and CuFeS2, composite film could be formed by mechanical stirring. It comes to a conclusion that the addition of PVB widens the crystalabsorption range of CuFeS2. When the optimal adding quantity of PVB was2g, thereappeared two characteristic absorption peaks. They are respectively200nm and400nmultraviolet absorption peaks. Also there appeared an infrared absorption peak near800nm.It is simply a physical mixture of PVB and CuFeS2crystals rather than chemical compoundwhich is good to retain the physical properties of both the physical and chemical structure,while it does not change the chemical structure of CuFeS2crystal. PVB content can beadded to improve the adhesion of composite membrane, but in view of the preparation ofcomposite materials, it also requiress good photoelectric absorption performance.Therefore, it concludes that the proportion of group C material has excellent adhesion andoptic-electronic properties. |
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