Bandgap and Interface Engineering for Advanced Electronic and Photonic Devices

Abstract

During the last decade a powerful new approach for designing semiconductor structures with tailored electronic and optical properties, bandgap engineering, has spawned a new generation of electronic and photonic devices. Central to bandgap engineering is the notion that by spatially varying the composition and the doping of a semiconductor over distances ranging from a few microns down to ~2.5 Å (~1 monolayer), one can tailor the band structure of a material in a nearly arbitrary and continuous way. Thus semiconductor structures with new electronic and optical properties can be custom-designed for specific applications. The enabling technology which has made bandgap engineering an exciting reality with far reaching implications for science and technology is molecular beam epitaxy (MBE), pioneered by Cho and Arthur in the late 1960s. In the subsequent decade MBE demonstrated jts ability to create ultra-thin (10–100 Å) layers and atomically abrupt interfaces between two different semiconductors (heterojunctions).