Electric field effects in a two-dimensional Disordered Hubbard-Mott model

We have studied the effects of disorder, correlation, external electric field, impurity concentration, and impurity location near and at the Si-SiO₂ interface of a metal-oxide-semiconductor field-effect transistor, in the range of experimental interest. We show that the intraimpurity correlation energy and the binding energy have strong dependence with the applied electric field and the impurity location on the interface. Taking into account all the above effects the Hubbard-Mott scenario is presented. As a result we obtain a critical concentration of about 10¹¹cm^-2, which can be discussed in terms of recent experimental findings.