Responsivity properties of GaAs based Blocked-Impurity-Band detectors

GaAs-based Blocked-Impurity-Band (BIB) detector, as a potential high-sensitive, low noise Terahertz (THz) detector, has been developed for the broad application in the area of THz security check and astronomy mission. In this work, GaAs:Si and GaAs:Te BIB detectors were fabricated. Their responsivity properties were measured at T=3.5K, under different biases and the same black body temperature of 1000K. The experimental results reveal that the GaAs:Si BIB device has a higher responsivity of 66 mA/W (V_bias=1V), about 5 times higher than that of GaAs:Te BIB device. This work demonstrates Si as a suitable choice of doping element for the absorption layer of GaAs based BIB detectors.