Quantum Capacitance of 2D Material - II

Now we have seen the shift in the Fermi energy is \(\delta E_F = e\delta \phi_e + \frac{\delta N}{D_0}\). If the geometrical capacitance of the sheet per unit area is \(C_0\), \(\delta \phi_e = C_0 \delta \sigma\) where \(\delta \sigma\) is the charge density per unit area, \(\delta \sigma = e \delta N\).