The Study Of Carbon Nanotubes Surface Enhanced Raman Scattering In THz Region

Raman Spectroscopy is a physical quantity that has an unique "identity" function,and it has been widely used in various probes and detection.Surface Enhanced Raman Scattering(SERS)can make up for the weakness of Raman signals and enhance the effect of Raman spectroscopy.Terahertz technology ha s been used in a wide range of industries like detection,communications,medical,security and so on.Carbon nanotubes is an ideal one-dimensional material,which have unparalleled advantages in terms of mechanical,electrical,optical and thermal.If the three kinds of technology are associated,it is more likely to make significant breakthroughs in applies in researching and developing high precision,high efficiency and small volume detection equipment.This task has mainly made the following achievements:1?Expounds the principle,development and application situation of the three techniques mentioned above in detail.And it Mainly explains the principle and causes of the Raman scattering and the basic principle of finite difference time domain(FDTD)method.2?After describing the dielectric constant of the metal,it has figured out the calculation formula of the carbon nanotubes dielectric constant.Then it elaborated the calculation method of complex permittivity when carbon nanotubes filled with substrate material.3?According to the theory above,it arouses the model of carbon nanotubes.Under the help of FDTD-Solutions,we did numerical simulation to carbon nanotubes model and pure carbon nanotubes model respectively.It has been found that the coupling effects between the filled material and the carbon atoms of the substrate in equivalent model have made the SERS effects of equivalent model exceed than in the model without adding base material.In addition,the strongest enhancement factor can achieved 61.5x10.4?Finally,it has discussed the SERS electromagnetic enhancement law of nanoparticles ball in that model.Whether changing the radius of the ball pellets with fixed ball distance or changing the distance of the ball pellets with fixed radius,the region electromagnetic enhancement has always increased firstly and then decreases afterwards.Only in the case that two variables are in certain ratios,and the sizes of balls match the wavelength of the incident light at the same time,it can produce the strongest SERS phenomenon.