Si1−xGex/Si multiple quantum well infrared detector

Abstract

A long‐wavelength infrared detector is demonstrated using Si_1−xGe_x/Si multiple quantum wells for the first time. A broad peak in the photoresponse is observed near 9 μm with a full width at half maximum of about 80 meV which provides the response in the 6–12 μm 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*=1×10⁹ cm √Hz/W at 77 K are achieved. This suggests the possibility of monolithic integration of Si_1−xGe_x/Si multiple quantum well detectors with signal processing electronics for potential focal plane array applications.