The properties of germanium-tin alloys for infrared device applications

Germanium-tin alloys are attracting renewed interest for applications including the strain control of CMOS active channels in integrated circuits, and mid-infrared optical devices for medical imaging, chemical spectroscopy, and military counter-measures. With sufficient Sn content above about 10 %, there is the particularly interesting possibility of an energy bandgap that is direct in reciprocal space, which may lead to efficient light emitters and detectors. Findings indicated that GeSn alloys and structures have interesting electrical and optical characteristics and may become useful for future electronic and optoelectronic devices.