Institut fur Nanotechnologie, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany.
ACS Nano. 2010 May 25;4(5):2748-54. doi: 10.1021/nn100337t.
The large-scale integration of devices consisting of individual single-walled carbon nanotubes (SWCNT), all of the same chirality, is a critical step toward their electronic, optoelectronic, and electromechanical application. Here, the authors realize two related goals, the first of which is the fabrication of high-density, single-chirality SWCNT device arrays by dielectrophoretic assembly from monodisperse SWCNT solution obtained by polymer-mediated sorting. Such arrays are ideal for correlating measurements using various techniques across multiple identical devices, which is the second goal. The arrays are characterized by voltage-contrast scanning electron microscopy, electron transport, photoluminescence (PL), and Raman spectroscopy and show identical signatures as expected for single-chirality SWCNTs. In the assembled nanotubes, a large D peak in Raman spectra, a large dark-exciton peak in PL spectra as well as lowered conductance and slow switching in electron transport are all shown to be correlated to each other. By comparison to control samples, we conclude that these are the result of scattering from electronic and not structural defects resulting from the polymer wrapping, similar to what has been predicted for DNA wrapping.
将由相同手性的单个单壁碳纳米管 (SWCNT) 组成的器件大规模集成，是实现其电子、光电和机电应用的关键步骤。在这里，作者实现了两个相关的目标，第一个目标是通过从通过聚合物介导的排序获得的单分散 SWCNT 溶液中进行电介质电泳组装，来制造高密度、单手性 SWCNT 器件阵列。这种阵列非常适合将各种技术的测量结果与多个相同器件相关联，这是第二个目标。该阵列通过电压对比扫描电子显微镜、电子输运、光致发光 (PL) 和拉曼光谱进行了表征，并显示出与预期的单手性 SWCNT 相同的特征。在组装的纳米管中，拉曼光谱中的大 D 峰、PL 光谱中的大暗激子峰以及电子输运中的电导降低和缓慢开关，都被证明彼此相关。通过与对照样品进行比较，我们得出的结论是，这些是由于聚合物包裹引起的电子而不是结构缺陷引起的散射，这与 DNA 包裹的预测相似。
