High-detectivity quantum-dot infrared photodetectors grown by metalorganic chemical-vapor deposition

A mid-wavelength infrared photodetector based on InGaAs quantum dots buried in an InGaP matrix and deposited on a GaAs substrate was demonstrated. Its photoresponse at T=77 K was measured to be around 4.7 mu m with a cutoff at 5.5 mu m. Due to the high peak responsivity of 1.2 A/W and low dark-current noise of the device, a specific peak detectivity of 1.1x10(12) cm Hz(1/2) W-1 was achieved at -0.9 V bias.