Quantum-dot infrared photodetectors and focal plane arrays

We report our recent results about mid-wavelength infrared quantum-dot infrared photodetectors (QDIPs) grown by low-pressure metalorganic chemical vapor deposition. A very high responsivity and a very low dark current were obtained. A high peak detectivity of the order of 3x10(12) Jones was achieved at 77 K. The temperature dependent device performance was also investigated. The improved temperature insensitivity compared to QWIPs was attributed to the properties of quantum dots. The device showed a background limited performance temperature of 220 K with a 45 degrees field of view and 300K background. The current device problems are a low quantum efficiency and a stronger than expected performance degradation as a function of operating temperature. Possible ways to improve the quantum efficiency and operating temperature are discussed.