From the point of view of its fundamental properties, solid solution Hg<sub>1-x</sub>Cd<sub>x</sub>Te (0 less than or equal to x less than or equal to l) (MCT) is one of very attractive
materials of infrared optoelectronics and has received considerable attention over the past forty odd years. In the early 90s,
bulk growth of MCT was phased out for the routine production of first generation photo-conductive devices. But it is hard
process to growth MCT single crystals with homogeneous composition. This fact determined a vital importance change in
the MCT technology during the last decade which first at all induced by the mostly replacement of bulk growth by epitaxial
technologies (LPE, MBE, VPE etc.).
Uncooled photoelectromagnetic detectors (PEM-detector) on the basis of cadmium - mercury telluride solid solutions of
composition x < 0.2 find application in opto-electronic systems with use of the C0<sub>2</sub>-laser radiation with wave-length of 10.6
μM.  To advantages of such detectors it is possible to attribute absence of an external electric supply that reduces a level
of noise and considerably reduces thermal loading on photodetector as well as it is a high speed responsivity that allows to
use them in heterodyne systems of registration.
The theoretical calculations of parameters of PEM detector has been carried out and results of development and research of
uncooled PEM-detector on basis of Cd<sub>x</sub>Hg<sub>1-x</sub>Te with x=0.2 of 6÷7 μm range of spectrum are represented by us in paper .
At the heart of work the researches of parameters of the PEM detector depending on a level of acceptor doping of the
semiconductor have been discounted.
In the present work the results of research of an opportunity of increasing of parameters of the PEM detector on basis of
Cd<sub>x</sub>Hg<sub>1-x</sub>Te with x = 0.167 corresponding to a maximum of spectral sensitivity on wave-length of 10.6 μm at room
temperature are represented.
The calculation of dependence photoelectric parameters of the uncooled photoelectromagnetic (PEM) detector of infrared range of spectrum on the basis of monocrystals Cd<sub>x</sub>Hg<sub>1-x</sub>Te (x=0,2) from the level of an acceptor doping of semiconductor material was carried out. It is shown that the optimum acceptor doping allows to increase essentially both the voltage response and specific detectivity of photodetector. The modified construction of the PEM detector permitting to increase more its voltage response is represented. The photoelectric parameters of manufactured PEM detector for middle range of IR-spectrum of 3-7 μm with a maximum of responsivity near 6 μm are given.