| A. K. Geim and K.S. Novoselov successfully manufactured the two-dimensionalgraphene with only an atom thick by the mechanical stripping method in2004. Thisnew carbon nanomaterials shows the unique physical properties in the optics、electrics、mechanics、calorifics and so on other fields, especially in optoelectronicsfield possessing a great application potential, and attracts greatly researchers’ researchinterests.The tight-binding model is used to describe the band structure of monolayer、bilayer and ABA trilayer grapheme, and get the corresponding eigenvalue andeigenfunction. Then, we deduce the single photon and two photon absorptioncoefficient of the monolayer、bilayer、trilayer graphene respectively by using thesecond order perturbation theory, getting the corresponding math expressions,analyzing the change of the absorption coefficient changing with incident lightwavelength. we use Mathematica8.0calculation software to calculat the singlephoton and two photon absorption coefficient of the different layers graphene, usingthe Origin8.5software to draw the corresponding absorption lines, analyzing theincident light wavelength making a difference to the light absorption, comparing thecalculated results and experimental results and analyzing whether there is anydifference between them, verifying the correctness of the theoretical calculation.The results show that one-photon absorption coefficient of monolayer grapheneis a constant about6.8×107m1, demonstrating that the absorptivity of incident light inmonolayer graphene approximates to2.3%.It is consistent with the experimentalresults. The two-photon absorption coefficient of bilayer graphene and trilayergraphene exhibit a giant resonance absorption peak in the infrared region whose theorder of magnitudes attain respectively10-4m/W、10-5m/W.Our results will provide theoretical guidance for graphene experimental design,and the application of graphene in the research field of the solar cells、the touch paneland so on optoelectronic devices. |
PDF Full Text Request