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 (LEDlight-emitting diode (LED)s), resonant cavity LEDs and vertical-cavity surface-emitting lasers (VCSELvertical cavitysurface emitting laser (VCSEL)quantumcascade laser (QCL)quantum well (QW)solar cellsuperlattice (SL)avalanche photodiode (SL-APD)quantum well (QW)light modulators), 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.