Use of nBn structures to suppress surface leakage currents in unpassivated InAs infrared photodetectors

Abstract

Surface leakage current is a significant source of dark current in conventional narrow-gap p-n junction photodetectors. It is shown that the nBn photodetector, which was originally designed to eliminate dark current arising from generation-recombination mechanisms, also effectively eliminates surface leakage currents. The result is a measured dark current lower by over six orders of magnitude than that of the InAs p-n photodetector for device temperatures of 140 K.