Molecular statics simulation of CdTe grain boundary structures and energetics using a bond-order potential

The structure and energetics of coincidence site lattice grain boundaries (GB) in CdTe are investigated by mean of molecular statics simulations, using the Cd-Zn-Te bond-order potential (second iteration) developed by Ward et al (2012 Phys. Rev. B 86 245203; 2013 J. Mol. Modelling 19 5469-77). The effects of misorientation (S value) and interface plane are treated separately, complying with the critical need for full five-parameter characterization of GB. In addition, stoichiometric shifts, occurring between the inner interfaces and their adjacent atomic layers, are also predicted, revealing the energetic preference of Te-rich boundaries, opening opportunities for crystallography-based intrinsic interface doping. Our results also suggest that the intuitive assumption that Sigma 3 boundaries with low-indexed planes are more energetically favorable is often unfounded, except for coherent twins developing on {111} boundary planes. Therefore, Sigma 5, 7 or 9 boundaries, with lower interface energy than that of twin boundaries lying on different facets, are frequently encountered.