Point Defects in Semiconductors

This chapter focuses on the physico-chemical aspects of point defect formation and of defect–impurity interactions in semiconductors. It discusses the properties of defects in ionic solids. The chapter addresses atomic defects and impurities in Group IV semiconductors, not only for their technological importance, but also because defects in elemental semiconductors present a well understood behaviour, in comparison with that of compound semiconductors. In these materials vacancies and interstitials are thermodynamically stable as individual species, interact with themselves, with impurities and with extended defects and induce the presence of shallow and deep levels in the gap, with a massive influence on their bulk properties and on their technological applications. The chapter further talks about point defects and non-stoichiometry in compound semiconductors, whose impact on the development of modern microelectronics, optoelectronics and radiation detection is substantial.