Vibronic Structure in Room Temperature Photoluminescence of the Halide Perovskite Cs3Bi2Br9.
We report a study on the optical properties of the layered polymorph of vacancy-ordered triple perovskite Cs3Bi2Br9. The electronic structure, determined from density functional theory calculations, shows the top of the valence band and bottom of the conduction band minima are, unusually, dominated by Bi s and p states, respectively. This produces a sharp exciton peak in the absorption spectra with a binding energy that was approximated to be 940 meV, which is substantially stronger than values found in other halide perovskites and, instead, more closely reflects values seen in alkali halide crystals. This large binding energy is indicative of a strongly localized character and results in a highly structured emission at room temperature as the exciton couples to vibrations in the lattice.
Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
Kelsey K
KK
Bass
Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
Laura
L
Estergreen
Kathleen Lonsdale Materials Chemistry, University College London (UCL) , 20 Gordon Street, London WC1H 0AJ, United Kingdom.
Christopher N
CN
Savory
Kathleen Lonsdale Materials Chemistry, University College London (UCL) , 20 Gordon Street, London WC1H 0AJ, United Kingdom.
John
J
Buckeridge
Kathleen Lonsdale Materials Chemistry, University College London (UCL) , 20 Gordon Street, London WC1H 0AJ, United Kingdom.|Diamond Light Source Ltd. , Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom.
David O
DO
Scanlon
Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
Peter I
PI
Djurovich
Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
Stephen E
SE
Bradforth
Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
Mark E
ME
Thompson
Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
Brent C
BC
Melot