Comparison of InAs/GaAs quantum dot infrared photodetector and GaAs/(AlGa)As superlattice infrared photodetector

A 10-stacked InAs/Ga As quantum dot infrared photodetector (QDIP) is compared with a 20-period GaAs/(AlGa) As superlattice infrared photodetector (SLIP). The 2-10 mum wide detection window and 187 mA/W high peak responsivity of InAs/GaAs QDIP at 7 mum at an applied voltage of 1.1 V are Superior to the 7-10 mum detection window and 140 mA/W responsivity of GaAs/(AlGa)As SLIP at 9.4 mum at an applied voltage of 1.3 V. The photocurrent of SLIP is temperature-independent, whereas the photocurrent of QDIP increases with increasing temperature from 20 to 100 K. The polarization-dependent response ratios of 0.22 and 0.39 are observed for SLIP and QDIP respectively.