Fabrication And Property Of One Dimensional Semiconductor Nanowires

In this dissertation, one-dimensional semiconductor nanowires were fabricated in the nanochannels of aluminum oxide membrane (AAO) by electrochemical technique successfully, and their morphologies and structures, photoelectricity properties were also determined. The influence factors, preparation mechanism were also investigated.Cu₂O nanowires were successfully synthesized by an electrochemical method using an alumina membrane as template. The composition and morphology of nanowires were characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photo potential and electrochemical impedance spectr- oscopes experiments of Cu₂O/AAO were also studied. According to SEM, the diameter of the Cu₂O nanowires is equivalent to the diameter size of the pores (about 120nm) and their length depends on the electrodeposition time (here we prepared up to 2-μm-long wires). The electrochemical impedance of Cu₂O/AAO was much smaller under the light of 365nm.Nickel oxide nanowires were prepared by means of oxiding the nickel nanowires electrodeposited in AAO template. The composition and morphology of the nanowires were characterized by using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The photo potential experiments of NiO/AAO were also studied. XRD results indicated that these NiO nanowires crystallize with a faced-cubic structure and the size of NiO crystal was about 50 nm. According to SEM, the diameter of the NiO nanowires was equivalent to the diameter size of the pores (about 90nm) and their length depended on the electrodeposition time used in the preparation of nickel nanowires (here we prepared up to 25-μm-long wires). The photo potential of 40V-NiO/AAO was better than that of 60V-NiO/AAO under the light of 365nm. The photo current was 0.4μA.ZnO nanowires were fabricated by two methods (electrodeposition and oxidation). The morphologies and properties of ZnO nanowires were characterized by SEM and UV-vis. The UV-vis pattern showed that the absorbance edge of ZnO nanowires was blue shifted relative to that of bulk ZnO.Semiconductor p-n junction nanowires were fabricated by electrodeposition and oxidation in AAO template. According to SEM, the diameter of the NiO/ZnO nanowires was equivalent to the diameter size of the pores (about 90nm). The photocurrent density of Cu₂O/ZnO p-n junction was 10μA/cm², its real photocurrent density was much bigger than that of Cu₂O/ZnO film. The mechanism of the photo electricity was also investigated.