A variation on the standard homodiode type-II superlattice with an M -barrier between the π -region and the n -region is shown to suppress the dark currents. By determining the optimal doping level of the M -superlattice, dark current densities of 4.95 mA cm2 and quantum efficiencies in excess of 20% have been demonstrated at the moderate reverse bias of 50 mV; allowing for near background-limted performance with a Johnson-noise detectivity of 3.11× 1010 cm HzW at 77 K for 14.58 μm cutoff wavelength for large area diodes without passivation. This is comparable to values for the state-of-the-art HgCdTe photodiodes.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)