Bi-Functional High-Speed and Ultrabroad Bandwidth Detector

Ultra-broadband detection and imaging devices with high speed, high bandwidth, and high sensitivity are in great demand for a variety of technological applications. An ultra-broadband high-speed device is realized based on a p-GaAs homojunction interfacial work function internal photoemission detector-photodiode device (HIWIP-photodiode). The ultrabroad dual-band response from terahertz (THz) to short-wavelength-infrared (SWIR) (4.2–150 THz) and visible/near-infrared (VIS/NIR) (330–450 THz) regions is realized by intentionally constructing two kinds of contact structures as well as utilizing various absorption mechanisms simultaneously. In addition, the HIWIP-photodiode could be used as a high-resolution ultra-broadband pixelless imaging device for THz to SWIR regions. The pixelless imaging of the mid-infrared spot is further demonstrated. These unique characteristics of an ultrabroad response range, bi-functional operating mode, mature growth/fabrication process, and high-speed response make the HIWIP-photodiode a strong contender for miniaturized and monolithic optoelectronic systems, paving the way for application of the interfacial work function internal photoemission (IWIP)-photodiode, which provides an alternative strategy for photon-type ultra-broadband detection.