Ge/Si photodetectors and group IV alloy based photodetector materials

Photodetecctors using Si, Ge and other group IV alloys are of current interest for use at telecommunication wavelength 1550 nm. We have presented in this paper our work on resonant cavity enhanced (RCE) Si/SiGe multiple Quantum Well (MQW) and Ge Schottky photodetectors. Tensile strained Ge layers grown with suitable barriers show direct gap type I band alignment. Predicted performance of photodetectors using strong Quantum Confined Stark Effect and Franz-Keldysh effects in these structures and properties related to photodetection using these new materials are also described.