STRAINED-LAYER PIEZOELECTRIC SEMICONDUCTOR-DEVICES

III-V semiconductors are piezoelectric. Quantum wells grown pseudomorp hically strained on the (111) face are axially polarized and include s trong, built-in de electric fields. The associated loss of inversion s ymmetry in the wells has important consequences for the electrooptic p roperties of these structures. They can be exploited to improve the pe rformance of a number of existing optoelectronic devices and also to g enerate new ones. In this paper we review some of these properties and discuss the work at Sheffield investigating the prospects for improve d performance and novel devices in the strained InGaAs/AlGaAs/GaAs and InGaAs/InAlAs/InP systems. (C) 1997 Elsevier Science Ltd.