An Investigation into the Thermoelectric Characteristics of Silver-based Chalcopyrites Utilizing a Non-empirical Range-separated Dielectric-dependent Hybrid Approach

TL;DR

This paper employs a non-empirical hybrid computational approach to analyze and identify silver-based chalcopyrites with high thermoelectric efficiency, surpassing the critical ZT threshold of one.

Contribution

It introduces a novel combination of dielectric-dependent hybrid functional with Boltzmann transport theory to accurately predict thermoelectric properties of Ag chalcopyrites.

Findings

Materials with ZT > 1 identified

Enhanced understanding of phonon scattering mechanisms

Potential for high-efficiency thermoelectric devices

Abstract

Our investigation explores the intricate domain of thermoelectric phenomena within silver (Ag)-infused chalcopyrites, focusing on compositions such as AgXTe$_2$ (where X=Ga, In) and the complex quaternary system Ag$_2$ZnSn/GeY$_2$ (with Y=S, Se). Using a sophisticated combination of methodologies, we integrate a non-empirical screened dielectric-dependent hybrid (DDH) functional with semiclassical Boltzmann transport theory. This approach allows us to conduct a detailed analysis of critical thermoelectric properties, including electrical conductivity, Seebeck coefficient, and power factor. Our methodology goes beyond superficial assessments, delving into the intricate interplay of material properties to reveal their true thermoelectric potential. Additionally, we investigate the often-overlooked phenomena of phonon scattering by leveraging both the elastic constant tensor and the deformation potential method. This enables a rigorous examination of electron relaxation time and lattice thermal conductivity, enhancing the robustness of our predictions and demonstrating our commitment to thorough exploration.Through our rigorous investigation, we identify materials with a thermoelectric figure of merit (ZT = $\sigma S^{2}T/ \kappa$) exceeding the critical threshold of unity. This significant achievement signals the discovery of materials capable of revolutionizing efficient thermoelectric systems. Our findings delineate a promising trajectory, laying the groundwork for the emergence of a new class of Ag-based chalcopyrites distinguished by their exceptional thermoelectric characteristics. This research not only contributes to the understanding of materials science principles but also catalyzes transformative advancements in thermoelectric technology.