Calculation Pipeline for Thermoelectrics and Defects in 2D Thin Films

Welcome to the calculation pipeline for studying thermoelectrics, 2D thin films, and defect-related properties using Quantum Espresso and other DFT/MD tools. This guide outlines a systematic workflow for geometry optimization, defect calculations, energy profile analysis, electronic structure analysis, and phonon calculations.

We use Cr-doped Sb₂Te₃ as an example system to demonstrate the various computational methodologies.

Overview of Calculation Steps

The key branches in this workflow are as follows:

Geometry Optimization
Structural relaxation of pristine and doped systems.
Defect Calculations
Substitutional and interstitial doping analysis.
Formation energy calculations.
Energy Profile Analysis
Formation energy.
Migration energy pathways.
Electronic Structure Analysis
Band structure.
Density of States (DOS) and Partial DOS (PDOS).
Charge density distribution.
Phonon Analysis
Lattice dynamics and thermoelectric properties.
Phonon dispersion relations.

Tools Used

Quantum Espresso: DFT-based structural and electronic property calculations.
Phonopy: Phonon calculations for lattice dynamics.
Matplotlib, NumPy, and Pandas: For post-processing and data visualization.

System Example: Cr-Doped Sb₂Te₃

We consider the Cr-doped Sb₂Te₃ system with two defect configurations:

Substitutional doping: Cr atom replacing an Sb site (( \text{Cr}_\text{Sb} )).
Interstitial doping: Cr atom occupying a void (( \text{Cr}_\text{int} )).

Each step in the pipeline is demonstrated using this system.

Geometry Optimization
Defect Calculations
Energy Profile Analysis
Electronic Structure Analysis
Phonon Analysis

Contribution

This pipeline and documentation were prepared by:

Yi Cao
Email: ycao73@jh.edu

For any queries, suggestions, or contributions, please contact the author.

References