MBE Growth and Characterization of Three-Terminal Ge(dot)/SiGe(well) Near-Infrared Photodetectors

The requirements of Si-based photonic devices in the next generation of chip technologies have caused extensive studies on Ge/Si quantum dot devices. In this communication, we report on lateral three-terminal FET type of photodetectors based on Ge dot layers sandwiched between SiGe QWs, where the near-infrared light was mainly absorbed in the Ge island layers. In addition to the source and drain contacts, a gate contact was implemented to control the carrier transfer along the layer stack direction. Very high photo-response was observed with a negative gate bias, accompanied with a significant increase of the carrier lifetime