Calculation of band offset in chalcopyrite system

A recently reformulated tight binding method is used to calculate valence band offset (VBO) at the CuInSe2/CuGaSe2 heterojunction. The hybrid energy is calculated in the s2p2 configuration and a new model for the average hybrid energy is used. The theoretical VBO value of 0.05 eV is in good agreement with recent experimental value of 0.04 eV. The value of conduction band offset is 0.60 eV giving a type I alignment. The VBO varies linearly with bond length difference (l), as VBO=(0.24)l.