John Ingall^1*, Edward Linscott^2,3, Nicola Colonna^2,3*, Alister Page⁴, Vicki Keast¹

1 Discipline of Physics, The University of Newcastle, Callaghan, New South Wales 2308, Australia

2 Laboratory for Materials Simulations, Paul Scherrer Institut, 5232 Villigen, Switzerland, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland

3 National Centre for Computational Design and Discovery of Novel Materials (MARVEL), Paul Scherrer Institut, 5232 Villigen PSI, Switzerland

4 Discipline of Chemistry, The University of Newcastle, Callaghan, New South Wales 2308, Australia

* Corresponding authors emails: john.ingall@uon.edu.au, nicola.colonna@psi.ch

DOI10.24435/materialscloud:hz-6e [version v1]

Publication date: Jan 14, 2025

How to cite this record

John Ingall, Edward Linscott, Nicola Colonna, Alister Page, Vicki Keast, Accurate and efficient computation of the fundamental bandgap of the vacancy-ordered double perovskite Cs₂TiBr₆, Materials Cloud Archive 2025.9 (2025), https://doi.org/10.24435/materialscloud:hz-6e

Description

Metal halide perovskites (MHPs) demonstrate an exceptional combination of properties. Rapid progress has extended their application beyond solar cells, light-emitting diodes, photodetectors, and lasers to include memristors, artificial synapse devices, and pressure induced emission. In particular, the vacancy-ordered double perovskite Cs₂TiBr₆ has been identified as a promising material. The effective characterization of MHPs requires accurate and efficient methods for the calculation of electronic structure. Koopmans compliant (KC) functionals are an accurate and computationally efficient alternative to many-body perturbation theory using the GW approximation but have yet only been validated on a small number of simple materials. In this work, KC functionals were applied to the more complex case of Cs₂TiBr₆ and gave a zero-temperature fundamental gap of 4.28 eV, in close agreement with the value of 4.44 eV obtained using the accurate, but more computationally expensive, evGW₀ approach. The temperature-dependent renormalization of the bandgap has also been investigated and found to be significant. Agreement with the experimental optical bandgaps of 1.76–2.0 eV would also require the inclusion of exciton binding energy.

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repo-v1-jpcc-3c07957.tar.gz MD5md5:01255eedc3f4ac9d89e560ac7fc6125a	36.2 MiB	Archive with input/output files to reproduce the results and simulations discussed in the journal article

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Keywords

Metal halide perovskites Koopmans functionals Quasi-particle self-consistent GW MARVEL