Chapter 6 - Valence Force Field Model and Its Applications

Abstract

The valence force field model for semiconductors with the diamond, zinc blende, and wurtzite structures is presented in this chapter. The mixed sublattices in ternary alloys of two binary compounds have the zinc blende and wurtzite structures that are slightly distorted. The deformation energies of the tetrahedral cells in ternary alloys are obtained. These energies demonstrate simultaneous tendencies to the decomposition and the formation of the superstructure in the disordered alloys with several certain compositions. The alloys with such compositions may undergo the discontinuous and continuous order–disorder phase transitions. The possible types of the superstructures in the ternary alloys with the zinc blende and wurtzite structures are described. Carbon and Sn isoelectronic impurities in Ge have the tendency to form 4Sn1C tetrahedral clusters identical in size, shape and composition. The strained energies due to the isoelectronic impurities in binary semiconductor compounds with the zinc blende structure are derived.