Schottky barrier photodiodes obtained by vacuum evaporation of the semi-transparent film over the surface of single crystalline Hg3In2Te6 substrates pre-treated by Ar ion bombardment. The responsivity maximum of the photodiodes is at the wavelength of 1.55 μm, corresponding to the transmission window in silica glass fiber with the minimal optical losses. The dark current in the diodes is determined by generation-recombination processes in the space-charge region and quantitatively governed by the Sah–Noyce–Shockley theory. A comparison of the photoelectric parameters of Hg3In2Te6 and Ge photodiodes is reported. The speed of the photodiode response is in the range 10–8 s to 10–7 s. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)