Electrical transport properties of pH-induced single diamond nanowire self-assembly

• Main Authors: Chen, Ting-Hao, 陳廷豪
• Other Authors: Sun, Kien-Wen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/9w6aa8

碩士 === 國立交通大學 === 應用化學系碩博士班 === 105 === Abstract Diamond nanowire self-assemblies were synthesized from diamond nanoparticles via wet chemical processes in buffered solution at room temperature with different pH values. Nanowire self-assemblies with diameters range from 300 nm to 1200 nm and lengths from 2 m to 10 m were produced. A single diamond nanowire device was fabricated using lithography techniques to study the electrical transport properties in those self-assembled nanowires. The transport properties and temperature dependence in electrical conductivity in temperatures ranging from 300 K to 80 K of single diamond nanowires were reported. I-V characteristics showed linear and symmetrical behavior through the entire temperature range, which indicated that the contacts are ohmic. The resistivity and contact resistance were accurately determined using two- and four-point probe schemes. The transport properties were dominated by the thermal activation of electrons from the Fermi level to the conduction band for a temperature above 220 K and to the three-dimensional Mott variation range hopping at a lower temperature. The conduction electrons are originated from the sp2 carbon on the fluorescent nanodiamonds surface. In the trans-conductance measurements, we find that the electrical conductivity of ND-Cysteamine nanowire can not be modulated by the applied gate bias. This is partially due to poor carrier concentration in the material. Another possible reason is that the appropriate dielectric material should be used in the three-terminal device.