Department Chemie and CeNS, Ludwig-Maximilians-Universität, 81377 Munich, Germany.
ACS Nano. 2012 Jul 24;6(7):6416-21. doi: 10.1021/nn301979c. Epub 2012 Jun 4.
We present the first photocurrent measurements along single carbon nanotube (CNT) devices with 30 nm resolution. Our technique is based on tip-enhanced near-field optical microscopy, exploiting the plasmonically enhanced absorption controlled by an optical nanoantenna. This allows for imaging of the zero-bias photocurrent caused by charge separation in local built-in electric fields at the contacts and close to charged particles that cannot be resolved using confocal microscopy. Simultaneously recorded Raman scattering images reveal the structural properties and the defect densities of the CNTs. Antenna-enhanced scanning photocurrent microscopy extends the available set of scanning-probe techniques by combining high-resolution photovoltaic and optical probing and could become a valuable tool for the characterization of nanoelectronic devices.
我们展示了具有 30nm 分辨率的首个沿单根碳纳米管 (CNT) 器件的光电流测量结果。我们的技术基于尖端增强近场光学显微镜，利用由光学纳米天线控制的等离子体增强吸收。这使得可以对由接触处的局部内置电场中的电荷分离引起的零偏置光电流进行成像，并且可以对靠近无法使用共焦显微镜分辨的带电粒子进行成像。同时记录的喇曼散射图像揭示了 CNT 的结构特性和缺陷密度。通过结合高分辨率光伏和光学探测，天线增强扫描光电流显微镜扩展了现有的扫描探针技术套件，并且可能成为纳米电子器件特性描述的一种有价值的工具。
