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

摘要

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 X 10~(10) cm~2 were grown on a GaAs/InP matrix. Photoresponse was observed at temperatures up to 160 K with a peak of 6.4 μm and cutoff of 6.6 μm. Very low dark currents and noise currents were obtained by inserting Al_(0.48)In_(0.52)As current blocking layers. The background-limited performance temperature was 100 K. A detectivity of 1.0 X 10~(10)cmHz~(1/2)/W was obtained at 77 K with a bias of-1.1 V.