Exploring the Cs-Te phase space via high-throughput density-functional theory calculations beyond the generalized-gradient approximation

TL;DR

This study employs high-throughput density-functional theory calculations using the SCAN functional to explore the phase space of Cs-Te compounds, aiming to identify stable structures and electronic properties relevant for photocathode applications.

Contribution

It introduces a new workflow for high-throughput DFT calculations with the SCAN functional applied to the Cs-Te system, expanding computational screening capabilities beyond GGA approximations.

Findings

Identified stable Cs-Te structures with varying Cs content.

Analyzed electronic properties such as band structures and density of states.

Provided insights into structure-property relationships for photocathode materials.

Abstract

Boosted by the relentless increase of available computational resources, high-throughput calculations based on first principles methods have become a powerful tool to screen a huge range of materials. The backbone of these studies are well-structured and reproducible workflows efficiently returning the desired properties given chemical compositions and atomic arrangements as sole input. Herein, we present a new workflow designed to compute the stability and the electronic properties of crystalline materials from density-functional theory using the SCAN approximation for the exchange-correlation potential. We show the performance of the developed tool exploring the binary Cs-Te phase space which hosts cesium telluride, a semiconducting material widely used as photocathode in particle accelerators. Starting from a pool of structures retrieved from open computational material databases, we analyze formation energies as a function of relative Cs content and for a few selected crystals, we investigate the band structures and density of states unraveling interconnections among structure, stochiometry, stability, and electronic properties. Our study contributes to the ongoing research on alkali-based photocahodes and demonstrates that high-throughput calculations based on state-of-the-art first-principles methods can complement experiments in the search for optimal materials for next-generation electron sources.