Photodiode devices with GeSn active layers can be integrated directly on p+ Si platforms under CMOS-compatible conditions. It has been found that even minor amounts of Sn incorporation (2%) dramatically expand the range of IR detection up to at least 1750 nm and substantially increases the absorption. The corresponding photoresponse can cover of all telecommunication bands using entirely group IV materials.
STATEMENT OF GOVERNMENT FUNDING
 The invention described herein was made in part with government support under grant number DEFG3608GO18003, awarded by the Department of Energy; and grant number FA9550-06-01-0442 awarded by the United States Air Force Office of Scientific Research (AFOSR). The United States Government has certain rights in the invention.