Accuracy of existing atomic potentials for the CdTe semiconductor compound

Area of Science:

• Materials Science
• Computational Physics
• Semiconductor Physics

Background:

• Cadmium Telluride (CdTe) and its alloys like Cadmium Zinc Telluride (CZT) are vital semiconductors for solar cells, radiation detectors, and medical imaging.
• Performance limitations in these technologies are often linked to nano- and micro-scale defects introduced during manufacturing.
• Molecular dynamics (MD) simulations are powerful tools for understanding atomic-scale defects, but their accuracy depends heavily on the interatomic potential used.

Purpose of the Study:

• To evaluate the performance and transferability of two existing literature interatomic potentials (Stillinger-Weber and Tersoff forms) for CdTe.
• To assess their ability to accurately predict structures, energies, melting behavior, and crystalline growth during vapor deposition.
• To identify limitations and provide insights for developing improved potentials for MD simulations of defects in CdTe.

Main Methods:

• Molecular dynamics simulations were employed to evaluate two literature potentials for CdTe.
• Simulations included calculations of structures and energies for various lattices, defects, and surfaces.
• Melting temperature calculations and vapor deposition simulations were performed for both potentials.

Main Results:

• The Stillinger-Weber potential correctly predicted the lowest energy structure for CdTe.
• However, this potential demonstrated insufficient transferability for accurate defect studies.
• The Tersoff potential's performance was also evaluated against ab initio calculations and experimental data.

Conclusions:

• Neither of the evaluated literature potentials is fully suitable for comprehensive molecular dynamics simulations of defects in CdTe.
• Further development is needed to create more transferable interatomic potentials for accurate defect modeling in CdTe and related alloys.
• Improved potentials will enhance the design and performance of CdTe-based technologies.