Effects of covalency, p-d coupling, and epitaxial strain on the band offsets of II-VI semiconductors -: art. no. 165336

Using the first-principles all-electrons method, we have systematically studied the natural band offsets among zinc blende BeX, MgX, and ZnX (X=S, Se, Te). We show that ZnX, which has large anion p-cation d repulsion, always has higher natural valence band maximum (VBM) than BeX and MgX, whereas BeX, which shows strong covalency, has higher natural VBM than MgX due to kinetic-energy-induced valence band broadening. However, epitaxial strain could reverse these trends. We found that for these isovalent semiconductors, the band offset is not sensitive to interface atomic compositions.