Normal-incidence InAs self-assembled quantum-dot infrared photodetectors with a high detectivity

An InAs/AlGaAs quantum-dot infrared photodetector based on bound-to-bound intraband transitions in undoped InAs quantum dots is reported. AlGaAs blocking layers were employed to achieve low dark current. The photoresponse peaked at 6.2 mum. At 77 K and -0.7 V bias, the responsivity was 14 mA/W and the detectivtiy, D*, was 10(10) cm.Hz(1)/(2)/W.