The advantages of p-type and design methodologies for Si1−xGex far-infrared (terahertz) quantum well infrared photodetectors (QWIPs)

This work is motivated by the desire to extend the operating wavelength of contemporary quantum well infrared photodetectors from the mid- (View the MathML source) to the far-infrared (View the MathML source) or terahertz region of the electromagnetic spectrum without recourse to liquid helium temperatures. This apparently simple objective hides many challenges which stem from the parasitic current that flows even in the absence of any illumination—the so-called dark current.