Solid State Electronic Devices, 7th Edition

5.8 Heterojunctions

Thus far we have discussed p-n junctions formed within a single semiconductor (homojunctions) and junctions between a metal and a semiconductor. The third important class of junctions consist of those between two lattice-matched semiconductors with different band gaps (heterojunctions). We discussed lattice-matching in Section 1.4.1. The interface between two such semiconductors may be virtually free of defects, and continuous crystals containing single or multiple heterojunctions can be formed. The availability of heterojunctions and multilayer structures in compound semiconductors opens a broad range of possibilities for device development. We will discuss many of these applications in later chapters, including heterojunction ...