Study on the spectral response characteristics of GaAs-based blocked-impurity-band detectors

We have developed a GaAs-based Blocked-Impurity-Band (BIB) Detector for the application of Terahertz (THz) security check and astronomical observation. In this work, we have fabricated GaAs:Si and GaAs:Te BIB detectors and analyzed their spectral response characteristics at 3.5K The experimental results of GaAs:Si BIB device demonstrate that the spectral response increases when the bias rises from 0.2 to 2.8V, and the peak wavelength is around 190 μm. The doping elements can form several discrete energy levels in the absorbing layer of GaAs:Si and GaAs:Te BIB detectors, which induce multi-peaks in the spectra. Our results show the potential of GaAs-based BIB detectors as novel, broad-spectrum, and high-performance THz detectors.