Narrow-gap semiconductor HgCdTe is one of the important elements used by the new IR-photonics. The well-developed technological methods suitable for preparation of different structures based on the material and high flexibility of the modern doping techniques made it possible to obtain materials with various properties. This article deals with some characteristics of photodiodes created by B ion implantation of this compound. Photoresponse of Hg<sub>1-x</sub>Cd<sub>x</sub>Te<B<sup>+</sup>> -based photodiodes is investigated. The peculiarities observed experimentally can be determined by effects occuring in the region of n<sup>+</sup>-p-junction due to local inhomogeneity of boron impurity and irradiation defects taking place under the process of the diodes preparation. It has been found that the processes of transport and recombination of the injected minority carriers are effected by these inhomogeneities. Auger-recombimation is revealed as a dominant process in the interval of the impurity conduction. At the same time, the minority carriers' lifetime is decreased due to appearance of low-ohmic sections of the current registered experimentally. The form of the current pulse observed in n<sup>+</sup>-p-junctions is explained by electrons recombination in the base of the junction under forward direction of the current. Spectral and noise properties and kinetic characteristics of the HgCdTe-based photodiodes are also studied.
Electrical characteristics of metal-semiconductor structure based on monocrystals Ag<SUB>3</SUB>SbS<SUB>3</SUB> are reported. Studies carried out at the room temperature were shown space-charge limited current caused by the peculiarities of Ag<SUB>3</SUB>SbS<SUB>3</SUB> crystallographic structure: velocity saturation mode and ballistic regime were observed. Results of the numerical modeling of experimental data are also presented.