Bi-Functional High-Speed and Ultrabroad Bandwidth Detector

Ultra-broadband detection and imaging devices with highspeed,high bandwidth, and high sensitivity are in great demand for a varietyof technological applications. An ultra-broadband high-speed deviceis realized based on a p-GaAs homojunction interfacial work functioninternal 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) (330-450THz) regions is realized by intentionally constructing two kinds ofcontact structures as well as utilizing various absorption mechanismssimultaneously. In addition, the HIWIP-photodiode could be used asa high-resolution ultra-broadband pixelless imaging device for THzto SWIR regions. The pixelless imaging of the mid-infrared spot isfurther demonstrated. These unique characteristics of an ultrabroadresponse range, bi-functional operating mode, mature growth/fabricationprocess, and high-speed response make the HIWIP-photodiode a strongcontender for miniaturized and monolithic optoelectronic systems,paving the way for application of the interfacial work function internalphotoemission (IWIP)-photodiode, which provides an alternative strategyfor photon-type ultra-broadband detection.