New multilayer and graded gap optoelectronic and high speed devices by band gap engineering

Abstract

Superlattices and graded gap materials provide an unprecedented degree of freedom in device design. The use of molecular beam epitaxy in growing these new materials allows one to engineer the energy band diagram of a device to an unprecedented degree and to tailor it to a specific application (band gap engineering). Many new device concepts have emerged from this innovative approach. These include superlattice and graded gap avalanche detectors, channeling diodes, graded base bipolar transistors and staircase structures such as the solid state photomultiplier and repeated velocity overshoot devices.