Fully Depleted InP Nano-Layer for In-Device Passivation of InGaAs SWIR Detectors

We designed a p-n InGaAs/InP heterojunction photodiode with a novel passivation approach that employs a thin and fully depleted in-device (embedded in the p-n structure) p-InP layer. We comparatively characterized mesa-type detector pixels and experimentally observed expected passivating behavior. Characterization results under illumination indicated that fully depleted p-InP layer increases photo-current as well due to increasing device active area. Dark current analysis of detector pixels with different areas resulted in a suppression of surface dark current by nearly three times.