Optoelectronic Properties of Rare-Earth Based Halide Double Perovskites

- A High Throughput Study

Abstract

This study explores the possible improvement of the optoelectronic properties of halide double perovskites $A_2BB'X_6$, with $A \in$ {+1 species} such as Cs or Rb, $X \in$ {-1 species} such as Cl, Br or I, and B, B' chosen such that $\mathrm{B + B' =}$ +4. The aim of this study is to find compounds that can be mixed with a rare-earth element to potentially increase the optoelectronic properties. To this end, candidate materials were gathered from the Materials Project databases and previous high-throughput studies, sorted for both structural and thermodynamic stability, and their electronic structures were calculated at the level Density Functional Theory (DFT) using MetaGGA functionals, which offer a significant improvement towards the description of electronic structure of materials compared to typically used semi-local functionals.

Several promising combinations were identified, predominantly with A = Cs and X = Cl. It was observed that rare-earth elements generally resulted in larger bandgaps, while elements from the 3d row of the periodic table exhibited smaller bandgaps.

Database

This repository contains the results of this study in fulfillment of Fredrik Lord's Master's Thesis (30hp) in Applied Physics (LITH-IFM-A-EX--24/4384--SE).

Examiner: Sergei Simak

Supervisor: Utkarsh Singh