Stoichiometry control and point defects in compound semiconductors

For many years, deviations of stoichiometry correlated with the density of point defects; interstitials, vacancies, anti-sites, etc. has been neglected. However, control of these by vapor pressure showed significant effects on the properties of compound materials; moreover, crystal growth under controlled vapor pressure also produced nearly perfect crystals of very high quality. Also, some considerations based on the thermodynamics are described.