A room temperature photovoltaic detector for the mid-infrared (1.8-3.4 m) wavelength region

In this paper, we report on an (pin) photovoltaic detector operating in the mid-infrared spectral region. Basic detector characteristics have been measured and compared with other detectors in this wavelength range. The typical detectivity of the photodiodes is cm at room temperature, which compares very favourably with that of TE cooled HgCdTe and is at least three times that of cooled PbSe photoconductors over the same wavelength range. The heterojunction photodiodes offer the advantage of increased sensitivity and extended wavelength response at room temperature compared with that of currently available commercial photodetectors, making them an attractive alternative for a number of mid-infrared applications including optical gas sensors and infrared spectrometers.