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=77K was measured to be around 4.7μm with a cutoff at 5.5μm. Due to the high peak responsivity of 1.2A∕W and low dark-current noise of the device, a specific peak detectivity of 1.1×1012cmHz1∕2W−1 was achieved at −0.9V bias.