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

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.