论文标题
金属电极对具有周期空位的曲折石墨烯纳米纤维的热电性能的影响
Effects of metallic electrodes on the thermoelectric properties of zigzag graphene nanoribbons with periodic vacancies
论文作者
论文摘要
我们理论上分析了用线或表面接触金属电极的石墨烯量子点阵列（GQDAS）的热电特性。这种GQDA被实现为具有周期空缺的曲折石墨烯纳米纤维（ZGNR）。这些GQDA中形成了间隙和小型班，它们可能具有金属和半导体阶段。具有非线性色散的第一个传导（价）迷你班的电子状态可能沿着锯齿形边缘方向具有很长的连贯长度。使用线接触金属电极，如果将ZGNR的扶手椅边缘原子耦合到电极，则GQDA具有串行耦合量子点（SCQD）的特性。相比之下，如果将锯齿形边缘原子耦合到电极，则GQDA具有平行QD的特性。在室温下，带有线接触的电极的SCQD的最大热电功率因子在室温下的最大热电学因子是相似或大于$ 0.186〜nw/k $的；他们的优点数字大于三。与表面接触的金属电极相比，具有线接触金属电极的GQDA的热电性能要好得多。
We theoretically analyze the thermoelectric properties of graphene quantum dot arrays (GQDAs) with line- or surface-contacted metal electrodes. Such GQDAs are realized as zigzag graphene nanoribbons (ZGNRs) with periodic vacancies. Gaps and minibands are formed in these GQDAs, which can have metallic and semiconducting phases. The electronic states of the first conduction (valence) miniband with nonlinear dispersion may have long coherent lengths along the zigzag edge direction. With line-contacted metal electrodes, the GQDAs have the characteristics of serially coupled quantum dots (SCQDs) if the armchair edge atoms of the ZGNRs are coupled to the electrodes. By contrast, the GQDAs have the characteristics of parallel QDs if the zigzag edge atoms are coupled to the electrodes. The maximum thermoelectric power factors of SCQDs with line-contacted electrodes of Cu, Au, Pt, Pd, or Ti at room temperature were similar or greater than $0.186~nW/K$; their figures of merit were greater than three. GQDAs with line-contacted metal electrodes have much better thermoelectric performance than surface contacted metal electrodes.
