  High quality p-type PbTe-CdTe monocrystalline alloys containing up to 10
at.$\%$ of Cd are obtained by self-selecting vapor transport method. Mid
infrared photoluminescence experiments are performed to follow the variation of
the fundamental energy gap as a function of Cd content. The Hall mobility,
thermoelectric power, thermal conductivity and thermoelectric figure of merit
parameter $ZT$ are investigated experimentally and theoretically paying
particular attention to the two-valence band structure of the material. It is
shown that the heavy-hole band near the $\Sigma$ point of the Brillouin zone
plays an important role and is responsible for the Pb$_{1-x}$Cd$_x$Te hole
transport at higher Cd-content. Our data and their description can serve as the
standard for Pb$_{1-x}$Cd$_x$Te single crystals with $x$ up to 0.1. It is
shown, that monocrystalline Pb$_{1-x}$Cd$_x$Te samples with relatively low Cd
content of about 1 at.\% and hole concentration of the order of 10$^{20}$
cm$^{-3}$ may exhibit $ZT \approx$ 1.4 at 600 K.
