[10a-W521-1~12] 17.2 Graphene

▲ [10a-W521-10] Quantum Dot Formation in Locally Doped Graphene Nano Ribbons

〇WANG Zhongwang¹, Jian Sun², Manoharan Muruganathan¹, Hiroshi Mizuta^1,3 (1.JAIST, 2.Central South Univ., 3.Hitachi Cambridge Laboratory)

Keywords:Graphene, Local doping, Quantum dot

Transport gap opens in graphene nanoribbons (GNRs) due to quantum confinement. Due to the unavoidable fabrication residue and edge roughness, the transport gap is not uniform. By controlling the local chemical potential of the GNR, transport gap at specific positions may serve as tunnel barriers thus quantum dots are formed. So far, controlling the tunnel barriers has been achieved by applying electrical field from local gates. Alternatively, it can be achieved through precisely doping GNRs. In this work, various doping features are introduced to different areas of GNRs from HSQ capping layer by changing the HSQ e-beam exposure conditions. By measuring the back gate modulation of source-drain conductance, various doping features in the same device are confirmed. Subsequently, pronounced single dot-like characteristic is observed in locally doped GNRs with a width of 30 nm and a length of 75 nm.