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Design And Applications Of Graphene Grating Sensor

Posted on:2017-04-02Degree:MasterType:Thesis
Country:ChinaCandidate:W DengFull Text:PDF
GTID:2271330488964472Subject:Communication and Information System
Abstract/Summary:PDF Full Text Request
Molecular vibration spectrum is an important fingerprint for the identification of material properties and characteristics, which has been widely used to determine the molecular structure, identify unknown compounds and analyze hybrid components.We firstly design one-dimensional and two-dimensional graphene grating sensor models, then use Rigorous Coupled-Wave Analysis(RCWA) and Finite Difference Time Domain(FDTD) methods to analyse and simulate gratings, find that:The resonance lambda of graphene gratings using RCWA and FDTD two methods are consistent with Fabry-Perot(F-P) theory, which illustrate the correctness and reliability of the two methods. Increasing graphene chemical potential, the sensor resonance peak shifts to a smaller wavelength, appearing blue shift phenomenon, while increasing refractive index of the substrate、period、duty ratio, the sensor resonance peak shifts to a larger wavelength, appearing red shift phenomenon. There are transmission bandwidths in addition to the resonance peak, which can be used as a sensor to detect and recognize molecular. Flexible adjustable characteristic structure parameters of the sensor model facilitate the flexible adjustment of the transmission bandwidth in practical application, which makes it easy to adjust the sensor of operating wavelength dynamicly. So we can make the sensor operate at different wavelengths,which will reduce input costs, improve economic efficiency and achieve green and sustainable development goal.Acetic anhydride、Methanol、Benzene、Toluene put in the detection area as the tested molecular, we find that the sensor transmission spectra and molecular vibration absorption spectrum changes consistently; molecular absorption is stronger, its transmission coefficient is smaller, which proves that the graphene grating sensor can detect and recognize molecuar directly. When we add Acetic anhydride, Methanol, Benzene, Toluene molecular in the detection area, simulation results show that sensor transmission coefficients were reduced by 79%、56%、51%、41% respectively for the one-dimensional graphene grating sensor compared with no molecular. We also simulate the effect of the tested sample’s thickness on transmission spectrum, simulation results show that sample’s thickness have no effect on the shape of transmission spectra.That is to say, transmission spectra is insensitive to sample’s thickness. The graphene grating sensors have a good robustness. Besides, we study different structural parameters affect the detection and recogniztion of Acetic anhydride molecular, simulation results show different combinations of structural parameters enables detection of Acetic anhydride, proving that the sensors have adjustable feature once again, which makes it possible to adjust structural parameters of graphene grating sensor to acheive molecular detection and identification for different wavelength range in practical applications.
Keywords/Search Tags:Graphene, Grating, Sensor, Transmission spectra, Molecular vibration spectrum
PDF Full Text Request
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