A Superlattice Barrier Based Quantum Well Infrared Photodetector with Maximum Sensitivity at Mid-Infrared Wavelengths

Quantum well infrared photodetectors based on the GaAs/AlGaAs material system where the aluminium mole fraction is below 0.45 are used for detecting long wavelength infrared radiation. By increasing the aluminium fraction these detectors can be made to detect shorter wavelengths as well, however this increase degrades detector performance. In this work we have studied a quantum well infrared photodetector with superlattice barriers where the structure is sensitive at mid infrared band. This is a new method for enabling GaAs/AlGaAs based quantum well infrared phototetectors to detect at mid-infared wavelengths without the need for higher aluminium mole fractions.