Si substrate based GaAs/AlGaAs quantum well infrared photodetector with Ge buffer

Ge buffer layer was introduced between the AlGaAs/GaAs quantum well infrared photodetectors active region and Si substrate, reducing threading dislocation density. The QWIPs on both Si and GaAs substrate exhibit similar responsivity, and detectivity. This work paves the way for CMOS compatible, on-chip mid-infrared detectors.