Study On The Electro-Optic Characteristic Of Typical Structure With Graphene Using FDFD Method

Since 2004, the physical and optical properties of graphene have been getting more and more attention by physicists and chemists. Nowadays, graphene is considered to be the hardest material in the world, and its theoretical specific surface area can reach 2630m2/g. The photoelectric properties of graphene is affected by many factors, such as, temperature, frequency, electromagnetic field and so on. Therefore, graphene which is a two-dimensional material has a good application prospect in energy materials, semiconductor optoelectronic devices and composite materials and so on.The improving of absorption efficiency and a tunable position of resonant peak are key attentions in most of structures. In this paper, with a chemical potential(or Fermi energy) applied, the conductivity and dielectric constant of graphene can be tuned. The amorphous silicon solar cell and the critically coupled resonator mainly aim to tune the positions of the absorption peaks and improve the absorption efficiency based on the graphene by using finite-difference frequency-domain method. Then, the reflection, the transmission and the absorption characteristics are also researched in these designs based on above theories. The main contents of this thesis are as follows:1. The basic theories of graphene films are described including their discovery, composition, physical and optical properties and so on. The expressions of the conductivity and dielectric constant are derived from KuBo formula under different conditions, and the electrical model of graphene is discussed in the region of visible and infrared light.2. The developments and basic principles of FDFD method are briefly discussed, and FDFD method has some advantages in the scattering problem, the oblique incidence and periodic structure compared with that in the finite difference time domain method. The theoretical formulas are derived, and the FDFD algorithm model in the two-dimensional periodic structure is deduced.3. At room temperature, the absorption enhancements and the tunable resonant peaks in the amorphous silicon solar cell and the critically coupled resonator are elaborated by using a tunable chemical potential of graphene in the region of visible and infrared light. Then, the data and analysis of the reflection, the transmission and the absorption characteristics in these two designs are achieved.