SI1-XGEX/SI MULTIPLE QUANTUM-WELL INFRARED DETECTOR

A long-wavelength infrared detector is demonstrated using Si1-xGex/Si multiple quantum wells for the first time. A broad peak in the photoresponse is observed near 9-mu-m with a full width at half maximum of about 80 meV which provides the response in the 6-12-mu-m range. The position of the peak in the photoresponse is in good agreement with that observed in the absorption measurement using a waveguide geometry. A peak responsivity of about 0.3 A/W and detectivity of D* = 1 X 10(9) cm square-root Hz/W at 77 K are achieved. This suggests the possibility of monolithic integration of Si1-xGex/Si multiple quantum well detectors with signal processing electronics for potential focal plane array applications.