Abstract

We have performed direct comparison of performance of a Pb_1-xSn_xTe(In) photodetector, a Si(Sb) BIB structure and a state of the art Ge(Ga) photoconductor in the integration cavity, using the same cryogenic equipment and measuring electronics. The Pb_1-xSn_xTe(In) photodetector shows several orders of magnitude higher responsivity S_I then the Si(Sb) BIB at the wavelength l ~ 14 m m. Persistent photoresponse with S_I ~ 10³ A/W at 40 mV bias and 1 s integration time at the wavelengths of l = 90 and 116 m m has been observed for the first time for the Pb_1-xSn_xTe(In) photodetector. This value is by a factor of ~ 100 higher than the respective parameters of the Ge(Ga) photoconductor in the same conditions. Indications exist that the red cutoff wavelength for this photodetector may exceed 220 m m - the highest l _co observed so far.

Thus, indium-doped lead telluride-based alloys are extremely sensitive photodetectors with a very wide spectral range covering all infrared and very possibly submillimeter regions. Their parameters exceed parameters of the existing state of the art analogs making them very attractive for many applications, such as infrared astronomy, sensitive far-infrared and submillimeter spectroscopy, medicine, and many others.

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