Dark current suppression in metamorphic In0.83Ga0.17As photodetectors with In0.66Ga0.34As/InAs superlattice electron barrier

We report on InP-based metamorphic In0.83Ga0.17As photodetectors with dramatically suppressed dark currents by inserting a strain-compensated In0.66Ga0.34As/InAs superlattice electron barrier in the In0.83Ga0.17As absorption layer. Compared with a reference detector without the barrier, the device showed that the dark current is reduced by about half at room temperature and is more than two orders of magnitude at 77 K at low bias, while the responsivity remained unchanged. The generation recombination and tunneling currents are significantly suppressed, and the dark current remains diffusion-current-limited above 175 K. The dark current density at −10 mV is reduced to 3.95 nA/cm2 at 175 K.