| In the past several decades, semiconductor nanomaterials have been widely investigated because their special characteristics that expect to facilitate photoelectrochemical activity, as well as separating the electron-hole pair through heterojunction. Meanwhile, the synthesis of p-type donor materials and acceptor materials has been widely studied.The CuAlO2 is a kind of p-type delafossite semiconductor nanomaterials. It is a kind of hopeful photoelectric materials and the synthesis method was simple. Broad band semiconductor ZnO is considered as the most promising electrode materials of solar cell because of the large exciton bingding energy, particular optic, electric properties, nice chemical stability and cheap as well as the good ability of utilization of the solar energy. The CuAlO2/ZnO heterojunction may be good for improving the photoelectrochemical performance. In this paper, the CuAlO2/ZnO/Ni nanostructure was successfully synthesized through sol-gel method and then annealed in vacuum. The performance of this nanostructure was widely studied. The main content and innovation of this thesis are listed as following:(1) The layer by layer CuAlO2 thin film was successfully synthesized through sol-gel method and then annealed in vacuum on the surface of Ni substrate. It was found that the crystal structure and morphology were influenced by the annealed procedure. Otherwise, the CuAlO2/Ni heterojunction was used to improve the photoelectrochemical characterization. Meanwhile, the photoelectrochemical performance of this heterojunction was well.(2) The nanofibers CuAlO2 thin film was successfully synthesized through the sol-gel procedure and than annealed in vacuum on the Ni substrate, which was annealed at 600℃for 2 h. The ohmic contact characteristic of this CuAlO2/Ni nanostructure was found. And it was different from the characterization of CuAlO2/Ni heterojunction. However, both of the short-circuit current and photovoltaic power conversion efficiency were higher than the result of the layer by layer CuAlO2/Ni for the more surface area of the nanofibers CuAlO2 thin film can increase the contact area with electrolyte. There, this result was beneficial to improve the photoelectrochemical performance.(3) The n-ZnO nanorod arrays/p-CuAlO2 laminar films/Ni nanostructure was successfully synthesized through hydrothermal reaction on the annealed laminar CuAlO2 thin film/ Ni substrates. The optical absorption performance of the as-synthesized sample was studied. Otherwise, there are two absorption peaks of UV-vis spectra, which correspond to the band-gap of ZnO and CuAlO2 nanostructure, respectively. The rectification characteristic of p-CuAlO2/n-ZnO heterojunction was studied. In addition, the photoelectrochemical characterization of n-ZnO nanorod arrays/p-CuAlO2 laminar films/ Ni nanostructure was better than CuAlO2 laminar films/ Ni. The result is from of:firstly, the well absorbantion performance is good for improving concentration of the photon-generated carrier: secondly, the ZnO nanorod is beneficial to improving the transport of the photon-generated carrier; thirdly, the photon-generated holes can transport to solid liquid interface for the contact area of ZnO nanorod and electrolyte solution is increased.(4) The n-ZnO nanorod arrays/p-CuAlO2 nanofibers film/ Ni nanostructure was successfully synthesized through hydrothermal reaction on the annealed nanofibers CuAlO2 thin film/Ni substrates. The heterojunction of CuAlO2/ ZnO was synthesized, which well rectification characteristic was found. The photoelectrochemical performance of this heterojunction was much higher than the result of CuAlO2 nanofibers film/ Ni nanostructure. The main reason were listed:firstly, the well absorbantion performance is good for improving concentration of the photon-generated carrier;secondly, the ZnO nanorod is beneficial to improving the transport of the photon-generated carrier; thirdly, the photon-generated holes can transport to solid liquid interface for the contact area of ZnO nanorod and electrolyte solution is increased. In addition, we explain the operational principle of "reverse" p-n junction.
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