Analytical bond-order potential for the cadmium telluride binary system

Abstract

CdTe and Cd 1-x Zn x Te are the leading semiconductor compounds for both photovoltaic and radiation detection applications. The performance of these materials is sensitive to the presence of atomic-scale defects in the structures. To enable accurate studies of these defects using modern atomistic simulation technologies, we have developed a high-fidelity analytical bond-order potential for the CdTe system. This potential incorporates primary (σ) and secondary (π) bonding and the valence dependence of the heteroatom interactions. The functional forms of the potential are directly derived from quantum-mechanical tight-binding theory under the condition that the first two and first four levels of the expanded Green's function for the σ-and π-bond orders, respectively, are retained. The potential parameters are optimized using iteration cycles that include first-fitting properties of a variety of elemental and compound configurations (with coordination varying from 1 to 12) including small clusters, bulk lattices, defects, and surfaces, and then checking crystalline growth through vapor deposition simulations. It is demonstrated that this CdTe bond-order potential gives structural and property trends close to those seen in experiments and quantum-mechanical calculations and provides a good description of melting temperature, defect characteristics, and surface reconstructions of the CdTe compound. Most importantly, this potential captures the crystalline growth of the ground-state structures for Cd, Te, and CdTe phases in vapor deposition simulations.

Analytical bond-order potential for the Cd-Zn-Te ternary system

“…Physics of the BOP have been discussed in detail previously 16 and hence will not be repeated here. For discussion of BOP parameterization, however, the mathematic formulation of the BOP is listed.…”

“…For discussion of BOP parameterization, however, the mathematic formulation of the BOP is listed. In the framework of the BOP, 16 the total energy of a system containing N atoms (i = 1, 2, . .…”

“…The version discussed here is extended from the published CdTe BOP. 16 These versions of CdTe and CdZnTe BOPs do not capture accurately the experimental lattice constant for zinc-blende CdTe. The other version of CdZnTe BOP captures accurately the lattice constant.…”

“…15 We recently developed a bond-order potential (BOP) for the Cd-Te binary system. 16 This BOP is particularly attractive because it is analytically derived from quantum mechanical theories [17][18][19][20][21] and is therefore more likely to be transferable to environments not explicitly tested. In particular, we demonstrated 16 that our Cd-Te BOP captures the property (i.e., atomic energies, atomic volumes, elastic constants, and melting temperatures) trends of a variety of structures, including clusters, bulk lattices, point defects, and surfaces, and can predict crystalline growth of both elements and compounds during molecular dynamics (MD) vapor deposition simulations.…”

The energetic impact of small Cd Te clusters on Cadmium Telluride

“…To simulate the impacts on the CdTe systems, we use analytical bond-order potentials (BOPs) [17,18] for the CdTe binary system [19,20]. The BOPs are based upon quantum-mechanical theories and can offer a more accurate description of interatomic interactions compared to Tersoff [21] and Brenner [22] types of potentials.…”