Quantum Wells, Superlattices, and Band-Gap Engineering

Abstract

This chapter reviews the principles of bandgap engineering and quantum confinement in semiconductors, with a particular emphasis on the optoelectronic properties of quantum wells. The chapter begins with a review of the fundamental principles of bandgap engineering and quantum confinement. It then describes the optical and electronic properties of semiconductor quantum wells and superlattices at a tutorial level, before describing the principal optoelectronic devices. The topics covered include edge-emitting lasers and light-emitting diodes (LEDs), resonant cavity LEDs and vertical-cavity surface-emitting lasers (VCSELs), quantum cascade lasers, quantum well solar cells, superlattice avalanche photodiodes, infrared detectors, and quantum well light modulators. The chapter concludes with a brief discussion of new research directions on quantum dot and nanowire structures.