Shin-ichi Honda

Copper oxide nanowires with good crystallinity and high aspect ratio have been attractive for use in high-performance optical and electronic devices. In this work, we fabricated copper oxide nanowires by thermal oxidation method. Copper oxide nanowires were fabricated at various heating times, keeping at a heating temperature of 500℃. When the heating time was over 30 minutes, the average width of the nanowires reached about 100 nm. It was observed that the bottom part of the nanowire was thick compared to the top part. We investigated the detailed structure by using micro-raman spectroscopy and electron backscatter diffraction (EBSD). From the results of raman spectra and EBSD crystal orientation mappings, it was found that Cu₂O/CuO heterostructure is formed at the thick region of the nanowire. Two type of heterostructures were confirmed, namely Cu₂O(110)/CuO(001) and Cu₂O(110)/CuO(110).

Abstract The chemical vapor transport method was used in this research to synthesize MoS₂ bulk. Through mechanical exfoliation, we limited the thickness of MoS₂ flakes from 1 to 3 μm. In order to fabricate a p–n homogeneous junction, we used oxygen plasma treatment to transform the MoS₂ characteristics from n-type to p-type to fabricate a p–n homogenous junction and demonstrate the charge neutrality point shift from −80 to +102 V successfully using FET measurement. The MoS₂ p–n homogeneous junction diode showed an excellent p-n characteristic curve during the measurements and performed great rectifying behavior with 1–10 V_pp in the half-wave rectification experiment. This work demonstrated that MoS₂ flake had great potential for p-n diodes that feature significant p–n characteristics and rectifying behavior.

Stockholm, Sweden, July 2-6, 2007

San Francisco, USA, April 9-13, 2007