IV-VI and IV-VI2 semiconductors are among the most interesting materials in semiconductor physics. The electrical properties of these semiconductors can also be tuned by adding impurity atoms. These semiconductors either have already found use or are promising materials for infrared sensors and sources, thermoelectric elements, solar cells, memory elements, etc. The basic characteristics of these compounds, namely, narrow band gap, high permittivity, relatively high radiation resistance, high mobility of charge carriers, and high bond ionicity, are unique among semiconductor substances. Because of their wide application in various devices, the search for new semiconductor materials and the improvement of existing materials is an important field of study. Doping with impurities is a common method of modifying and diversifying the properties of physical and chemical semiconductors. This book covers all known information about phase relations in ternary systems based on IV-VI and IV-VI2 semiconductors, providing еhe first systematic account of phase equilibria in ternary systems based on IIV-VI and IV-VI2 semiconductors and making research originally published in Russian accessible to the wider scientific community. This book will be of interest to undergraduate and graduate students studying materials science, solid state chemistry, and engineering. It will also be relevant for researchers at industrial and national laboratories, in addition to phase diagram researchers, inorganic chemists, and solid state physicists. Provides up-to-date experimental and theoretical information Allows readers to synthesize semiconducting materials with predetermined properties Delivers a critical evaluation of many industrially important systems presented in the form of two-dimensional sections for the condensed phases