Simulation of the capacitance–voltage characteristics of a single-quantum-well structure based on the self-consistent solution of the Schrödinger and Poisson equations

Abstract

The numerical self-consistent solution of the coupled Schrödinger and Poisson equations is used to simulate the C–V characteristic of Schottky barrier heterostructures with a single quantum well (SQW). This model is applied to study n-type SQW structures based on InGaAs/InAlAs. It has been shown from analysis of the C–V characteristics of a SQW structure that it is possible to extract information about the energy position of subband levels and the distribution of electron density in the QW. We have demonstrated that due to the two-dimensional distribution of electron gas in the QW the apparent concentration profile NC–V–W derived from the C–V characteristic fails to describe the free electron density distribution in the QW layer. However, the number of the NC–V–W peaks indicates the quantity of electron subband levels in the QW situated below the Fermi level at zero reverse bias.