Edge-Sensitive Semiconducting Behaviour in Low-Defect Narrow Graphene Nanoribbons

Nanomaterials and Nanotechnology

Syota Kamikawa¹  Junji Haruyama¹  Taisei Shimizu¹  Yuko Yagi¹ 

关键词: Graphene;    Nanoribbon;    Edge;    Semiconducting Behaviour;    Impurity Level;    Resonant Tunnelling;   

DOI  :  10.5772/58466

来源: InTech

【 摘 要 】

Low-defect graphene nanoribbons (GNRs) derived from the unzipping of carbon nanotubes have exhibited large energy band gaps (transport gaps), despite having widths in the order of ~100 nm. Here, we report on the unique semiconducting behaviour of very narrow, low-defect GNRs, with widths of less than 20 nm. Narrow GNRs are highly resistive, and additional annealing is required to reduce their resistivity. The GNRs display ambipolar rather than evident semiconducting behaviour (p- and n-types), exhibiting normalized Ion/Ioff as great as ~106 (close to those in a few nm-order-width GNRs) and which are very sensitive to the atmosphere and the termination of the GNRs' edges by foreign atoms (hydrogen for n-type and oxygen for p-type). It is also revealed that the activation energy (Ea ~35 meV) estimated from the temperature dependence of the minimum conductance is smaller than those in ~100 nm width GNRs. The observed sharp conductance peak on back-gate voltage (Vbg) dependence and its strong correlation with...

【 授权许可】

Unknown