Top sawtooth grating for GaAs/AlGaAs quantum well IR detectors

The enhancement factors for grating materials (GaAs and Si) in top sawtooth grating quantum well IR detectors are calculated. It is shown that the absorption processes are angle limited for GaAs gratings and are reflection limited for Si gratings. A major advantage of using Si gratings is that there is a nearly constant enhancement factor region, which will greatly ease restriction on device design and processing.