ABSTRACT
A method of realization of semiconductor heterojunctions by making sandwich structures is described. Quantum well formation is understood from energy band diagrams and by noting the band bending near the interface. The electron affinity rule for band-offset estimation is explained. Features of type I, II, and III heterojunctions are mentioned. The formation of a conducting channel with charge carriers separated from dopant ions paves the way toward modulation doping. The governing equations for heterojunction namely Poisson’s equation, the Schrodinger equation, and the equation for electron concentration are written down. As Poisson’s and Schrodinger’s equations do not allow analytical solution, the self-consistent solution sequence is followed. The general results of self-consistent solution for heterojunctions, viz. the width of the conducting channel and the sheet electron concentration, are highlighted.
