硅衬底上CdS纳米晶和纳米碳管极化特性的动态电场力显微术观察(英文)

Dynamic electric force microscopy observation of polarization of CdS nanocrystals and carbon nanotubes on silicon substrates

在现有的商用原子力显微镜上实现了用动态电场力显微术来研究单个纳米颗粒的极化特性。将AOT(bis( 2 ethylhexyl)sulfosuccinatedisodium)分子包覆的CdS纳米晶和Au纳米晶共同沉积在n型硅片表面 ,以分析导电探针对其诱导极化。同时研究了纳米碳管和碳纳米颗粒的不同极化特性。对样品的原位观察表明 :其半导体和金属介电特性的差别 ,CdS ,Au粒子呈现较大的极化反差 ,在同一纳米碳管不同位置也能观察到类似反差。通过比较在半导体和金属粒子上探针对外加交变电场的响应幅度 。

Dynamic electric force microscopy was set up on a commercial atomic force microscope (AFM) to study the polarization of single nanocrystal. CdS nanocrystals capped with bis(2 ethylhexyl) sulfosuccinate disodium(AOT) molecular and Au nanocrystals were co deposited on a n type silicon wafer to study the different polarizabilities induced by a conductive tip. Carbon nanotube was also studied and its polarization was compared with that of carbon nanoparticle. In situ observation showed that local metallic or semiconductive response caused the polarizability variation of CdS and Au nanocrystals and on different positions of the same nanotube. The dielectric constant can be estimated by comparing the vibration amplitude of cantilever under applied ac bias on metallic or semiconductive particles.