Strongly localized exciton states in layered BiI<sub>3</sub>: From bulk to monolayer

ORAL

Abstract

In this work, we carry out a detailed theoretical study of the electronic and optical properties of bulk and monolayer bismuth triiodide BiI3, a layered metal halide, using the ab initio GW+BSE scheme with a full spinorial formulation. We discuss the dimensionality effects in detail along with the role of spin-orbit coupling. Moreover, we compute the exciton dispersion by solving the BSE at finite momentum, also analysing transverse (TE) and longitudinal (LE) excitons, and the longitudinal-transverse splitting at q->0. In bulk, we find a peculiar direction-dependent hybridization of exciton with different character mediated by the long-range Coulomb interaction. Our work provides theoretical support to existing experiment, demonstrate that BiI3 is an important testbed for the theoretical study of fundamental exciton physics (such as phonon-mediated exciton interaction and localization) and finally confirms that this system is a promising material for the experimental investigation of exciton dynamics (such as tr-ARPES measurements).

*The authors acknowledge the funding of Ministerio de Ciencia e Innovación, which is part of Agencia Estatal de Investigación (AEI), through the project PID2020-112507GB-I00 QUANTA-2DMAT (Novel quantum states in heterostructures of 2D materials) and the Generalitat Valenciana through the Grant PROMETEO/2021/082 (ENIGMA) and the projects SEJIGENT/2021/034 and MFA/2022/009. J. C.-V. acknowledges the Contrato Predoctoral Ref. PRE2021-097581. A. M.-S. acknowledges the Ramón y Cajal programme (grant RYC2018-024024-I; MINECO, Spain). This study forms part of the Advanced Materials programme and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat Valenciana. D.S. and F.P. acknowledge funding from MaX "MAterials design at the eXascale" (Grant Agreement No. 101093374) co-funded by the European High Performance Computing joint Undertaking (JU) and participating countries. D.S. also acknowledges PRIN Grant No. 20173B72NB funded by MIUR (Italy).

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Presenters

  • Jorge Cervantes-Villanueva

    • University of Valencia

Authors

  • Jorge Cervantes-Villanueva

    • University of Valencia

  • Fulvio Paleari

    • Nanoscience Institute, CNR

  • Alberto Garcia-Cristobal

    • University of Valencia

  • Davide Sangalli

    • CNR-ISM, Division of Ultrafast Processes in Materials (FLASHit), Roma
    • Istituto di Struttura della Materia-CNR (ISM-CNR)
    • Istituto di Struttura della Materia (ISM)–CNR

  • Alejandro Molina-Sanchez

    • University of Valencia