Hennrich Frank, Krupke Ralph, Lebedkin Sergei, Arnold Katharina, Fischer Regina, Resasco Daniel E, Kappes Manfred M
Forschungszentrum Karlsruhe, Institut für Nanotechnologie, D-76021 Karlsruhe, Germany.
J Phys Chem B. 2005 Jun 2;109(21):10567-73. doi: 10.1021/jp0441745.
Resonance Raman spectroscopy/microscopy was used to study individualized single-walled carbon nanotubes (SWNTs) both in aqueous suspensions as well as after spin-coating onto Si/SiO2 surfaces. Four different SWNT materials containing nanotubes with diameters ranging from 0.7 to 1.6 nm were used. Comparison with Raman data obtained for suspensions shows that the surface does not dramatically affect the electronic properties of the deposited tubes. Raman features observed for deposited SWNTs are similar to what was measured for nanotubes directly fabricated on surfaces using chemical vapor deposition (CVD) methods. In particular, individual semiconducting tubes could be distinguished from metallic tubes by their different G-mode line shapes. It could also be shown that the high-power, short-time sonication used to generate individualized SWNT suspensions does not induce defects in great quantities. However, (additional) defects can be generated by laser irradiation of deposited SWNTs in air, thus giving rise to an increase of the D-mode intensity for even quite low power densities (approximately 10(4) W/cm2).
共振拉曼光谱/显微镜技术被用于研究个体化的单壁碳纳米管（SWNTs），既研究其在水悬浮液中的情况，也研究旋涂到Si/SiO₂表面后的情况。使用了四种不同的SWNT材料，其包含的纳米管直径范围为0.7至1.6纳米。与从悬浮液获得的拉曼数据比较表明，表面不会显著影响沉积管的电子性质。对于沉积的SWNTs观察到的拉曼特征类似于使用化学气相沉积（CVD）方法直接在表面上制造的纳米管所测量到的特征。特别地，单个半导体管可以通过其不同的G模式线形与金属管区分开来。还可以表明，用于生成个体化SWNT悬浮液的高功率、短时间超声处理不会大量诱导缺陷。然而，在空气中对沉积的SWNTs进行激光照射会产生（额外的）缺陷，从而导致即使在相当低的功率密度（约10⁴W/cm²）下D模式强度也会增加。
