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

Abstract

Cd-Zn-Te ternary alloyed semiconductor compounds are key materials in radiation detection and photovoltaic applications. Currently, crystalline defects such as dislocations limit the performance of these materials. Atomistic simulations are a powerful method for exploring crystalline defects at a resolution unattainable by experimental techniques. To enable accurate atomistic simulations of defects in the Cd-Zn-Te systems, we develop a full Cd-Zn-Te ternary bond-order potential. This Cd-Zn-Te potential has numerous unique advantages over other potential formulations: (1) It is analytically derived from quantum mechanical theories and is therefore more likely to be transferable to environments that are not explicitly tested. (2) A variety of elemental and compound configurations (with coordination varying from 1 to 12) including small clusters, bulk lattices, defects, and surfaces are explicitly considered during parameterization. As a result, the potential captures 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. (3) Most importantly, this potential is validated to correctly predict the crystalline growth of the ground-state structures for Cd, Zn, Te elements as well as CdTe, ZnTe, and Cd 1−x Zn x Te compounds during highly challenging molecular dynamics vapor deposition simulations.

A transferable force field for CdS-CdSe-PbS-PbSe solid systems

“…Two examples thereof are a transferable Stillinger-Weber (SW) potential developed for the Zn-Cd-Hg-S-Se-Te system 52 and a analytical bond order potential (ABOP) for Cd-Zn-Te systems. 53 These potentials cover several elements and can accurately reproduce the lattice parameters, elastic properties, and cohesive energies for II-VI binary compounds in the four-fold WZ or ZB structures. However, both the SW potential 52 and the ABOP 53 models failed to accurately reproduce the relative stabilities between the six-fold RS phase and the four-fold WZ and ZB phases.…”

“…A simple but effective partially charged rigid ion model (PCRIM) 54 was first used to develop a pair potential for CdSe by Rabani,55 and the model was extended to CdS and ZnS by Grünwald et al 39 In this model, effective charges of ±1.18 e were set for cations and anions, and Lennard-Jones (LJ) potentials were used to describe the short-range interactions (this model will be referred as the LJ model below). 39,55 Unlike the SM, SW potentials, and the ABOP model mentioned above 42,52,53 which are only valid to describe the four-fold WZ and ZB phases, this LJ model captured the energy features for three phases, WZ, ZB, and RS. 39,55 Therefore, it has been frequently used in simulation studies of phase transitions.…”

“…DFT and ab-initio-MD data are commonly included in the training sets to develop "nearly prefect" force fields to describe not only crystal structures, elastic, and vibration properties but also properties of high-pressure, metastable, liquid, and gas phases, and of different surfaces and interfaces. 33,34,47,53,59 On the other hand, a classical force field can never be prefect and one should be aware of the limitations of a force field.…”

Central-force decomposition of spline-based modified embedded atom method potential

“…∂E pot /∂r αβ . The central-force decomposition can then be obtained by calculating the central force F αβ according to (13) and (14). By applying the chain rule in the differentiation of (5), we obtain…”

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

“…The accuracy of such simulations relies on a careful parameterization of the considered atomistic potentials and an adequate choice of the probed time scales. In the case of CdTe, Ward and Zhou conducted detailed studies in this direction [6][7][8] and developed a bond-order potential (BOP) that has been found to yield particularly accurate results in term of vapor deposition [8] and defect energy trends, such as dislocation line energies [9], or vacancy and interstitial energies [7]. BOPs encompass a wider range of analytic interatomic potentials which adopt Pauling's [10] and Coulson's [11] bond-order concept.…”