Long wave infrared InAs-InGaAs quantum-dot infrared photodetector with high operating temperature over 170 K

Abstract

A long wave infrared InAs-InGaAs quantum-dot (QD) infrared photodetector (QDIP) with a peak detection wavelength of 9.9 µm and operating temperature of over 170 K is reported. Peak specific photodetectivity D* of 3.8 × 109 cm Hz1/2 W−1 and 1.3 × 108 cm Hz1/2 W−1 were obtained at the detector temperature T = 78 K and T = 170 K, respectively. A large photoresponsivity of 4.6 A W−1 and high photoconductive (PC) gain of > 144 were demonstrated at T = 170 K. The high temperature performance is attributable to the dark current reduction by the double Al0.2Ga0.8As barrier layers employed in the QDIP and the high PC gain at the elevated temperature. The performance demonstration indicates that the QDIP with double current-blocking barriers is promising for high-temperature long wave infrared photodetection.