Asymmetric superlattice quantum well infrared photodetector

A particular asymmetric superlattice (SL) with a structural defect was designed to operate as a quantum well infrared photodetector with detection energies in the mid-infrared range. The asymmetric quantum well infrared photodetector is based on InGaAs/InAlAs quantum wells lattice matched to the InP substrate. Due to the device asymmetry, it can operates in the photovoltaic mode (zero applied bias), showing potential to work at high temperatures, as well as in the photoconductive mode (positive or negative biases). The photocurrent spectra depend on the direction of the applied bias. The experimental results are in excellent agreement with the calculated absorption spectra.