In0.6Ga0.4As/GaAs quantum-dot infrared photodetector with operating temperature up to 260 K

A high-sensitivity In0.6Ga0.4As/GaAs quantum-dot infrared photodetector (QDIP) with detection wave band in 6.7-11.5 mum and operating temperature up to 260 K under normal incident illumination has been demonstrated. The peak detection wavelength shifts from 7.6 to 8.4 mum when the temperature rises from 40 to 260 K. The background limited performance (BLIP) detectivity (D-BLIP(*)) measured at V-b=-2.0 V, T=77 K, and lambda(p)=7.6 mum was found to be 1.1x10(10) cm Hz(1/2)/W, with a corresponding responsivity of 0.22 A/W. The high operating temperature is attributed to the very low dark current and long carrier lifetime in the quantum dots of this device. The results show that this QDIP can operate at high temperature without using the large band gap material such as AlGaAs or InGaP as blocking barrier to reduce the device dark current. (C) 2003 American Institute of Physics.