Abstract: The first principle was used to calculate the energy band and electronic density of states of N and S atom codoping, and to study the
 relationship between quantum capacitance and different doping configuration. The results show that the introduction of N/S and N/B codoping atoms can lead to localized state at Fermi level. In the range of -0.6 V to 0.6 V potential, the quantum capacitance of NSS,NS,NBB,NNB and NB doping structures is higher than that of pristine silicene. The quantum capacitance of NSS doping single vacancy silicene is 43.9 μF/cm² at Fermi level.

Key words: silicene, first principle, band structure, quantum capacitance