InP/InGaAs Photodetector Based on a High Electron Mobility Transistor Layer Structure: Its Response at 1.3 µm wavelength

We report on the investigation of the room-temperature optoelectronic behavior of a metal–semiconductor–metal two-dimensional electron gas photodiode based on the two-dimensional electron gas of a high electron mobility transistor structure. The photodetector is fabricated in the InP/InGaAs material system, without use of Al-containing layers. Optoelectronic measurements on a device with a finger spacing of 3 mm show a full width at half-maximum (FWHM) of the pulse response of <60 ps, which is the resolution limit of our measurement equipment. Low-temperature measurements at 40 K with electro-optical sampling at a wavelength of 890 nm show a FWHM of 1 ps.