Contain Vacancy Defects Of Zigzag Graphene Nano Charged To Learn The Nature Of The Research

Graphene has been one of the most interesting topics due to its unique geometry structure and electronic properties. Based on the Density Function Theory and Nonequilibrium Green’s functions method, we studied the eletronic structures and transport properties of vacancy defected zigzag graphene nanoribbons.At first, we have investigated the affect of vacancy defect to the eletronic structures and transport properties of zigzag graphene nanoribbons. The results show that all of these zigzag graphene nanoribbons with vacancy defect present the eletronic structures of metal, and their eletronic properties have a close relationship with the number of defect Carbon atoms. When the number of defect Carbon atoms is even, the degenerate state that around Fermi level just partly disappears, at the same time the current of these systems firstly increasing and then keeping invariant along with voltage increasing. While the number of defect Carbon atoms is odd, the degenerate state that around Fermi level disappears, and the current of these systems is increasing along with the increasing voltage.Secondly, we have investigated the spin polarization effect of vacancy defect of zigzag graphene nanoribbons. It’s found that when the number of defect Carbon atoms is odd, spin-polarized lead to the degenerate state that around Fermi level disappears, and there are band gaps appearing near Femi level, these systems change from metal to semiconductor. While the number of defect Carbon atoms is even, spin-polarized phenomenon happens. We can also found the defect band across Femi level, and the systems show the property of metal.Finally, we have studied the affect of band-width to eletronic structures of vacany defected zigzag graphene nanoribbons. It’s shown that with the increasing of band-width, the systems’band gap decreasing to zero, the systems’property change from semiconductor to metal, and magnetic moment increasing, the distribution of these systems’spin density of states have a change from central to two edges.