Preparation Of Thin Film Electrodes With Zinc Oxide-based Semiconductor Heterostructures And Their Photoelectric Conversion Properties

Semiconductor photoelectric materials use solar energy for the photocatalysis and photoelectric conversion,which is widely seen as a promising approach to the use of renewable resources.The solar energy converts to chemical energy and conversion efficiency of electrical energy are affected by the absorption of light and the migration,separation,recombination of photoelectric charge of semiconductor photoelectric materials.In traditional semiconductor materials,ZnO with stable chemical performance,widely sources,low cost,excellent photoelectric properties,strong ability to capture light and a good ability to capture the light hole overflow ability is studied widely.Nevertheless,due to wide band gap of ZnO?3.37 eV?,it mainly absorb the ultraviolet light and cannot effectively use visible light,which restricted the improvement of photoelectric conversion efficiency based on ZnO solar cell.Therefor,ZnO was modified by using narrow band gap semiconductor materials to construct nano-level heterostructure.This can not only make full use of visible light,but also realize the photoelectric conversion efficiency of photoelectrode under visible light.The ZnO/CuO and ZnO/Ag₃CuS₂ composite photoelectrodes were designed and prepared in this paper.The photocurrent test technology,photovoltaic technology,the test of flat band potential,cyclic voltammetry?CV?and differential pulse voltammetry?DPV?were carried out to study photoelectric properties and photocatalytic properties of the materials.The photoelectric conversion performance and the transport mechanism of photogenerated charge was investigated.Main research work includes:1.ZnO nanorod?NR?arrays were prepared by hydrothermal method on the fluorine doped tin oxide?FTO?conductive glass.A novel ZnO/CuO heterogeneous structure for photoelectrochemical?PEC?cells were developed,which was fabricated with CuO attached onto ZnO nanorod?NR?arrays by an electrochemical deposition method and annealing.CuO as a p-type and narrow band-gap sensitizer can make the n-type ZnO to respond visible light and promote the separation of photogenerated charge carriers by building a p-n heterogeneous structure.The photoelectric conversion and photocatalytic formaldehyde oxidation by ZnO/CuO were investigated in detail under simulated sunlight?AM1.5?in comparison with single ZnO NRs and CuO film.In addition,the energy level diagram of the p-n heterogeneous interface was revealed according to a theoretical analysis on the basis of the flat band potential results.2.ZnO/Ag₃CuS₂ nanocomposite was prepared by hydrothermal method and ion exchange method on the fluorine doped tin oxide?FTO?conductive glass.Scanning electron microscopy?SEM?,X-ray powder diffraction?XRD?and UV-vis diffuse reflection spectrum were used to analyze the morphology of the materials.The Ag₃CuS₂ modified ZnO nanoarrays were fabricated on FTO glass substrates,the photoelectric current has been improved proving that ZnO/Ag₃CuS₂ has excellent photoelectric conversion performance.