NEARLY FREE-CARRIER MODEL FOR CALCULATING THE CARRIER SPECTRUM IN HETEROSTRUCTURES

A method based on the weak-binding approximation is proposed for calcu lating the energy spectrum and the carrier wave functions in semicondu ctor heterostructures. It is shown that this method can be effectively used for a wide range of heterostructures in the absence and in the p resence of the external magnetic field oriented along the axis of the heterostructure. The structural features of the hole spectrum in super lattices consisting of a very thin layer of one semiconductor and a th ick layer of another semiconductor are studied. It is shown that in su ch superlattices the hole wave function is a superposition of several bulk states of light and heavy holes in which their mixing at the hete rojunction is taken into account. The hole spectrum of the superlattic es, which consist of asymmetric triangular wells, is calculated and an alyzed. (C) 1996 American Institute of Physics.