Band Gap Engineering of Crystal Materials: Band Gap Estimation of Semiconductors via Electronegativity

We have developed empirical equations to quantitatively calculate the band gap values of binary ANB8-N and ternary ABC2 chalcopyrite semiconductors from the general viewpoint of chemical bonding processes upon electronegativity (EN). It is found that the band gap of crystal materials is essentially determined by the binding energy of chemical bonds to the bonding electrons, which can be effectively described by the average attractive abilities of two bonded atoms to their valence electrons and the delocalization degree of the valence electrons. The calculated band gap values of a large number of compounds can agree well with the available experimental data. This work provides us an efficient approach to quantitatively predict the band gap values of inorganic crystal materials on the basis of fundamental atom parameters such as EN, atomic radius, etc.