Multiband fusion detection based on superstructure/ blocking-impurity-band combination detector (Invited)

Terahertz radiation refers to electromagnetic waves with a wavelength range of 30 μm-1 mm, characterized by strong penetration, high safety, strong specificity and good orientation. Therefore, terahertz technology has broad application prospects in the fields of astronomical observation, safety monitoring, substance identification and biomedicine. Blocking-impurity-band detector has the advantages of high sensitivity, large array size and wide detection spectrum, which is an excellent choice for terahertz radiation detection. At present, the blocking-impurity-band detector is mainly based on three material systems, namely Si, Ge and GaAs. Si, Ge and GaAs-based blocking-impurity-band detectors can be used for ultra-wide band detection from 3 μm to 500 μm. Superstructure is an artificial composite structure composed of subwavelength structural units. By introducing superstructure into the photoelectric detector, the electromagnetic field energy will be strongly localized at the interface between the metal and the detector through plasmon resonance and dipole resonance modes. So, the combination of superstructure and blocking-impurity-band detector can effectively regulate the detection peak, reduce the full width at half maximum (FWHM) of detection peak and enhance the spectral resolution ability. So it is expected to be widely used in multiband fusion detection of 3-500 μm. At the same time, the combination of the two technologies can further improve the response rate of the device, reduce the size of the device and reduce the process difficulty. This paper briefly described the working mechanism of the blocking-impurity-band detector. And the research history and status of blocking-impurity-band detector at home and abroad are also introduced. Finally, the superstructure/blocking-impurity-band detector was described in detail in terms of band regulation, spectral resolution and absorption enhance. Combining with the bottleneck problem of this technology, the future research prospect was proposed in the aspects such as high purity material growth and the mechanism of local effect of light field.