Pb/p-PbSe junction: An investigation of current-voltage and capacitance-voltage measurements

Molecular beam epitaxy has been used to grow p-PbSe/CaF2/Si(111) heterostructures. Using such stuctures, which are fully compatible with standard photolithographic technological procedures, photovoltaic sensors have been realized. The I(V) characteristics of the Pb/p-PbSe contacts have been investigated experimentally and theoretically over a wide temperature range from 4 to 300 K. Evidence of the contribution of bulk and surface impurity concentrations in the space charge region at high temperature is presented. The Schottky barrier height has been derived from a fit to the experimental data. We used the theory of Padovani and Stratton in the context of Fermi-Dirac statistics. In addition the capacitance-voltage characteristics of Pb/p-PbSe diodes have been investigated. The Schottky barrier height has been obtained and the existence of an inversion layer at the surface of p-type PbSe layer has been demonstrated.