InP-Based Quantum-Dot Infrared Photodetectors With High Quantum Efficiency and High-Temperature Imaging

We report a room temperature operating InAs quantum-dot infrared photodetector grown on InP substrate. The self-assembled InAs quantum dots and the device structure were grown by low-pressure metalorganic chemical vapor depositon. The detectivity was 6 times 10¹⁰ cm Hz^1/2/W at 150 K and a bias of 5 V with a peak detection wavelength around 4.0 mum and a quantum efficiency of 48%. Due to the low dark current and high responsivity, a clear photoresponse has been observed at room temperature. A 320 times 256 middle wavelength infrared focal plane array operating at temperatures up to 200 K was also demonstrated. The focal plane array had 34 mA/W responsivity, 1.1% conversion efficiency, and noise equivalent temperature difference of 344 mK at 120 K operating temperature.