Study On Preparation And Characterization Of Nanocomposite Semiconductor And Its Photoelectric Performance

The TiO₂ nanotube arrays were successfully made by using the TiO₂ sol-gel on the AAO.By the electrochemical deposition,the Cu₂O nanowaires grew from the TiO₂ nanotubes and the Cu₂O/TiO₂ nanocomposite semiconductor electrodes were successfully fabricated.Moreover,the ZnO films were successfully fabricated on the ITO surface by using the ZnO sol-gel,and the Cu₂O/ZnO nanofilm composite semiconductor electrodes were made by electrochemical depositing Cu₂O film.The concentration of Ti(OC4H9)4 and the deposition of Cu₂O have an effect on the topography and crystal forms of the nanocomposite electrodes,which were test by SEM,TEM,XRD.The open-circuit potential and AC Impedance of nanocomposite electrodes were also studied.By using the TiO₂ sol-gel,the AAO/TiO₂ nanotube arrays were made on the AAO at the condition of negative pressure.The TiO₂ nanotubes arrays were observed after dissolving the AAO by NaOH.The Cu₂O nanowaires were electrochemical-deposited in the TiO₂ nanotubes by the three-electrode method.The Cu₂O nanowaires coated by the TiO₂ nanotubes were watched clearly with using the TEM,the nanotube wall became thicker and thicker following the increasing of Ti(OC4H9)4 concentration,the substances of coating was proved to be Cu₂O by line scanning of TEM.The results of photoelectric response showed that the open-circuit potential of nanocomposite semiconductor electrodes of 30% concentration Ti(OC4H9)4 was the best,and the AC Impedance showed that the interface charge transfer resistance of which was excellent.The ZnO films were successfully made by ZnO sol-gel,it was found that the ZnO is hexagonal wurtzite structure.The results of photoelectric response showed that the ZnO films after 400℃heat treatment and 5 layers was the best property.Cu₂O/ZnO nanocomposite film electrodes were made by the three-electrode method,the results of photoelectric response showed that the thickness of ZnO film have much effect on the photoelectric properties of Cu₂O/ZnO nanocomposite film electrodes.When the thickness of ZnO film was thin,the migration of photohole from the Cu₂O to the ZnO was main reaction.However,the migration of photoelectron from the ZnO to the Cu₂O was the leading function when the thickness of the ZnO films became thicker.The EIS shows that the electrochemistry impedance value of Cu₂O/ZnO nano composite film electrode under visible light was smaller by contrast with UV-light.