Excitonic Anisotropy in Single‐Crystalline 2D Silver Phenylchalcogenides
Name
Advanced Optical Materials - 2025 - Lee - Excitonic Anisotropy in Single‐Crystalline 2D Silver Phenylchalcogenides.pdf
Description
Published version
Size
2.82 MB
Format
Adobe PDF
Checksum (MD5)
e7fdb9e4742c3a852fea71d15578d0a1
Author(s)
Lee, Woo Seok
Cho, Yeongsu
Posmyk, Katarzyna
Peksa, Paulina
Dyksik, Mateusz
Samulewicz, Nicholas
Plochocka, Paulina
Baranowski, Michał
Kulik, Heather J
Tisdale, William A
Date Issued
October 30, 2025
Journal
Advanced Optical Materials
Publisher
Wiley
Citation
Lee, Woo Seok, Cho, Yeongsu, Posmyk, Katarzyna, Peksa, Paulina, Dyksik, Mateusz et al. 2025. "Excitonic Anisotropy in Single‐Crystalline 2D Silver Phenylchalcogenides." Advanced Optical Materials, 13 (32).
Version
Final published version
Abstract
2D materials exhibiting in‐plane anisotropy enable new applications in directional energy transport and polarized optical response. Silver phenylchalcogenides (AgEPh) – including mithrene (AgSePh), tethrene (AgTePh), and thiorene (AgSPh) – represent an exciting new addition to this family, with optical response spanning the visible to near‐UV. Here, excitonic anisotropy is predicted and characterized in this family of materials using a combination of ab initio theory and optical micro‐spectroscopy of single‐crystalline flakes. Using density functional theory and GW with the Bethe–Salpeter equation calculations, it is revealed that all AgEPh compounds exhibit anisotropic electronic band structure and host multiple delocalized excitons with in‐plane anisotropy. Room‐temperature polarization‐resolved optical micro‐spectroscopy shows that orthogonally polarized excitons with similar energy lead to nearly isotropic absorption in AgSPh, whereas energy separation between excitonic resonances in AgSePh and AgTePh leads to strong absorption and emission anisotropy. Cryogenic reflectance micro‐spectroscopy further reveals exciton fine structure in AgSePh, reconciling the discrepancies between room‐temperature experiments and theoretical predictions. Finally, it is demonstrated that the optical response of thicker AgEPh crystals is influenced by photonic effects arising from finite crystal size. Overall, this work advances the understanding of the relationship between anisotropic structure, composition, and excitonic properties in AgEPh, providing a foundation for technological integration.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Massachusetts Institute of Technology. Department of Chemistry
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DOI of Published Version
10.1002/adom.202502435
