High-detectivity InAs quantum-dot infrared photodetectors grown on InP by metal–organic chemical–vapor deposition

We report a high-detectivity InAs quantum-dot infrared photodetector. The InAs quantum dots were grown by self-assembly on InP substrates via low-pressure metal–organic chemical–vapor deposition. Highly uniform quantum dots with a density of 4×1010cm2 were grown on a GaAs∕InP matrix. Photoresponse was observed at temperatures up to 160 K with a peak of 6.4μm and cutoff of 6.6μm. Very low dark currents and noise currents were obtained by inserting Al0.48In0.52As current blocking layers. The background-limited performance temperature was 100 K. A detectivity of 1.0×1010cmHz1∕2∕W was obtained at 77 K with a bias of −1.1V.