Electronic transport in monolayer nanoribbons of Zr2CO2 MXenes

In this paper, we study the properties of electronic transport in MXene Zr2CO2 nanoribbons of armchair type (AMNR). By using the tight-binding method, we obtain the band structure of this material and investigate the electron conductance with the non-equilibrium Green's function approach. It can be seen that increasing the width of the ribbon from 5-AMNR to 20-AMNR reduces the energy gap from 1.77 eV to 1.40 eV and also increases the maximum conductance from 7 e^2⁄(h )to 18 e^2⁄(h ). Increasing the width of the ribbon to 55-AMNR will eventually lead to the reduction of the energy gap to a limit value of 1.39 eV. For a nanoribbon with a certain width of 5-AMNR, we consider carbon and zirconium vacancies in three central, edge, and linear positions and show that the vacancy can reduce the energy gap up to 1.62 eV and eliminate the step mode of conductivity. Also, in the presence of vacancy, we see a decrease in the maximum conductance, and in some cases, this decrease reaches from 7 e^2⁄(h ) (in the case without vacancy) to less than 3 e^2⁄(h ). The results of this paper indicate the ability to adjust the band gap by changing the width of the ribbon and also control the conductance by applying the vacancy. These properties show the potential applications of this kind of MXene in nanoelectronic devices.