III-V semiconductors have attracted considerable attention due to their applications in the fabrication of electronic and optoelectronic devices as light emitting diodes and solar cells. The electrical properties of these semiconductors can also be tuned by adding impurity atoms. 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 quaternary systems based on III-V semiconductors, providing he first systematic account of phase equilibria in quaternary systems based on III-V semiconductors and making research originally published in Russian accessible to the wider scientific community. Features: Contains 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