标题: | pH值诱发自组装单根钻石奈米线之电性与电子传输行为研究 Electrical transport properties of pH-induced single diamond nanowire self-assembly |
作者: | 陈廷豪 孙建文 Chen, Ting-Hao Sun, Kien-Wen 应用化学系硕博士班 |
关键字: | 钻石;奈米线;diamond;nanowire |
公开日期: | 2016 |
摘要: | 摘要 利用分子间氢键的作用力使奈米钻石在不同pH值的磷酸盐生理食盐水相互连结形成长约3-10 m、直径约300-1200 nm的钻石奈米线,为了更加瞭解这种分子自组装合成的钻石奈米线基本电性,我们将单根钻石奈米线制作成元件以便进行量测。 我们将单根钻石奈米线制作成金氧半场效电晶体(MOSFET),以两点式探针量测奈米线电阻,量测得到的电阻为21.27M,而以四点式探针量测奈米线电阻为18.89M。对元件施加闸极没有观察到通道的变化,有可能是载子浓度低或是介电层的选择不当造成。接着我们藉由变温量测及变程跳跃传输理论可以推得温度在295K-81K区间电子有两种传输模式分别为热活化传输及三维变程跳跃传输,传导的自由电子主要来自萤光奈米钻石表面的sp2碳。 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. |
URI: | http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070352533 http://hdl.handle.net/11536/139820 |
显示于类别: | Thesis |