Pressure effect on electronic band structure of III–V compounds

Semi-empirical tight-binding sp3s* method for tetrahedrally co-ordinated cubic materials is used and applied to study the electronic band structure for GaAs, GaSb and GaP. These compounds are found to be indirect-gap semiconductors under pressure effect. The ionicity factor at critical transition pressure is presented by means of a recent empirical model. The structural phase transition can be seen from the behaviour of the bonding character. The obtained results are in reasonable agreement with experimental and theoretical data.