Excitons and light-emission in semiconducting MoSi2X4 two-dimensional materials

Minglei Sun, Michele Re Fiorentin, Udo Schwingenschlögl, Maurizia Palummo

Research output: Contribution to journalArticlepeer-review

42 Scopus citations


Semiconducting two-dimensional materials with chemical formula MoSi2X4 (X = N, P, or As) are studied by means of atomistic ground- and excited-state first-principles simulations. Full-fledged quasi-particle bandstructures within the G0W0 approach substantially correct the electronic bandgaps previously obtained with hybrid-functional density functional theory and highlight the absence of lateral valleys close in energy to the conduction band minimum. By solving the Bethe–Salpeter equation, we show that the optical properties are dominated by strongly bound excitons with the absorbance and maximum short-circuit current densities of MoSi2P4 and MoSi2As4 comparable to those of transition metal dichalcogenides. Due to the presence of the outer SiX layers, the exciton binding energies are smaller than those generally found for transition metal dichalcogenides. Long radiative lifetimes of bright excitons, over 10 ns at room temperature for MoSi2As4, and the absence of band-nesting are very promising for application in efficient ultra-thin optoelectronic devices.
Original languageEnglish (US)
Journalnpj 2D Materials and Applications
Issue number1
StatePublished - Nov 7 2022

Bibliographical note

KAUST Repository Item: Exported on 2022-11-11
Acknowledgements: M.S. and U.S. acknowledge the King Abdullah University of Science and Technology (KAUST) for funding the research reported in this publication. M.S. thanks Dr. Huabing Shu and Dr. Zhiyong Zhu for helpful discussions. M.R.F. and M.P. acknowledge CINECA for high-performance computing resources under the Iscra-B initiative. M.P. acknowledges funding from Tor Vergata University through the TESLA project and INFN through the TIME2QUEST project.


Dive into the research topics of 'Excitons and light-emission in semiconducting MoSi2X4 two-dimensional materials'. Together they form a unique fingerprint.

Cite this