We have compared directly the performance of a Pb1-xSnxTe(In) photodetector
with that of two other state-of-the-art far-infrared detectors: a Si(Sb) b
locked impurity band (BIB) detector and a Ge(Ga) photoconductor in an integ
rating cavity. The Pb1-xSnxTe(In) photodetector has current responsivity S-
I several orders of magnitude higher than the Si(Sb) BIB at wavelength lamb
da=14.5 mu m. Persistent photoresponse with S(I)similar to 10(3) A/W at 40
mV bias and 1 s integration time at the wavelengths lambda=90 and 116 mu m
has also been observed in the Pb1-xSnxTe(In) photodetector. This is larger
by a factor of similar to 100 than the responsivity of the Ge(Ga) photocond
uctor in the same conditions. (C) 2000 American Institute of Physics. [S000
3-6951(00)05120-2].