Two-dimensional p-n junction under equilibrium conditions

For the first time, the idea of a two-dimensional p-n junction formed as a contact between two regions of a quantum-dimensional film with different types of conductivity is proposed. Under equilibrium conditions, the potential distribution and the potential-barrier height were determined. An expression was derived for the width of the surface-charge layer, which depends linearly on the contact potential (external bias) in contrast to the three-dimensional case. The specific capacitance of a two-dimensional p-n junction is virtually independent of the applied potential and depends only on the ambient permittivity. It was shown that, in spite of the fact that the junction electric field is screened only slightly, the Schottky approximation can be used for a description of the properties of such p-n junctions.