Analytical Bond-Order Potential for the Cd–Te–Se Ternary System

Abstract

CdTe/CdSe core/shell structured quantum dots do not suffer from the defects typically seen in lattice-mismatched films and can therefore lead to improved solid-state lighting devices as compared to the multilayered structures (e.g., In x Ga 1−x N/GaN). To achieve these devices, however, the quantum dots must be optimized with respect to the structural details at an atomistic level. Molecular dynamics simulations are effective for exploring nano structures at a resolution unattainable by experimental techniques. To enable accurate molecular dynamics simulations of CdTe/CdSe core/shell structures, we have developed a full Cd−Te−Se ternary bond-order potential based on the analytical formalisms derived from quantum mechanical theories by Pettifor et al. 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 potential parametrization. More importantly, enormous iterations are performed to strictly ensure that our potential can simulate the correct crystalline growth of the ground-state structures for Cd, Te, and Se elements as well as CdTe, CdSe, and CdTe 1−x Se x compounds during molecular dynamics vapor deposition simulations. Extensive test simulation results clearly indicate that our new Cd−Te−Se potential has unique advantages over the existing literature potential involving Cd, Te, and Se elements.

A Modified Stillinger-Weber Potential for TlBr, and Its Polymorphic Extension

“…Here the melting temperature calculations follow the same method described previously Zhou, Foster, Van Swol, Martin, & Wong, 2014;Ward, Zhou, Wong, & Doty, 2013). It can be seen that our MSW model reproduces the experimental elastic constants for TlBr-CsCl.…”

Size- and composition-dependent structure of ternary Cd-Te-Se nanoparticles

“…Figures 8a-8d respectively show the radial distribution functions of the cadmium-cadmium (Cd-Cd), cadmium-tellurium (Cd-Te), cadmium-selenium (Cd-Se), tellurium-tellurium (Te-Te), tellurium-selenium (Te-Se), and tellurium-selenium (Se-Se) interactions of CdTe 0.50 Se 0.50 NP with 2.0 nm at 100 K, 300 K, 500 K, and 800 K. The RDFs are calculated for each atomic pair of the optimized CdTe 0.50 Se 0.50 . One can see that Cd-Se has a narrower and higher distribution than the other pair interactions because of the weaker bond [27] and the low atomic weight of the Se atom. In addition, there is a slight difference 0 100 200 300 400 500 600 700 800 900 between Te-Se and Se-Se atoms.…”

“…A modern version of molecular dynamics (MD) simulations with LAMMPS [25,26] was performed using Cd-Te-Se ternary analytical BOP [27]. The BOP formalism was constructed from CdTe BOP [28,29].…”

Pressure compression of CdSe nanoparticles into luminescent nanowires

“…The Cd-Se-Te analytical bond-order potential (BOP) ( 39 ) was used in the MD code LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator) ( 40 , 41 ) to perform the simulations. The BOP was tested through stringent MD simulations of crystalline growth.…”