Demonstration of a Novel Mid Infrared Device: The Quantum-Dot Avalanche Photodiode (QDAP)

In this paper we demonstrate an intersubband quantum dot detector coupled to an avalanche photodiode to improve the signal-to-noise ratio and increase the operating temperature of the device. Mid-infrared photodetectors, operating in the 50-400 meV (3-25 mum) regime, have a variety of potential applications in medical diagnostics, thermal imaging, night vision cameras for battlefield recognition systems, and chip-based detection of chemical warfare agents. Intersubband quantum dot detectors have been proposed as a promising technology due to their normal incidence excitation and lower dark currents. However, the low quantum efficiency leads to a lower detectivity, responsivity and limits their operating temperature to about 70-80 K