Enhanced spectral purity of WSe <sub>2</sub> quantum emitters via conformal organic adlayers
Quantum emitters in solid-state materials are typically embedded in the bulk of their hosts, making their electronic transitions inaccessible to surface modification. In contrast, two-dimensional materials, with their all-surface nature, offer a platform for tuning quantum emitters via chemical functionalization. Because of its semiconducting properties that enable electrical addressability, monolayer WSe<sub>2</sub> is a promising candidate for quantum emission, although the complex interplay between point defects and the localized strain needed to activate quantum emission leads to poor spectral purity. Here, we demonstrate that functionalizing monolayer WSe<sub>2</sub> with conformal adlayers of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) improves quantum emission spectral purity. Optical spectroscopy reveals that PTCDA functionalization lowers defect activation energies by 10 meV and induces a 30 nm redshift in quantum emission wavelength, while preserving the bright and dark exciton energies of monolayer WSe<sub>2</sub>. First-principles calculations corroborate these findings, thus providing molecular-level insight into the underlying mechanism of enhanced spectral purity.
Authors
- Tobin Jay Marks (ORCID: https://orcid.org/0000-0001-8771-0141)
- Xuedan Ma (ORCID: https://orcid.org/0000-0002-3163-1249)
- David D. Xu (ORCID: https://orcid.org/0000-0002-0413-7958)
- Fateme Mahdikhanysarvejahany (ORCID: https://orcid.org/0000-0002-5163-7293)
- Anushka Dasgupta (ORCID: https://orcid.org/0000-0003-3544-8334)
- Mark C. Hersam (ORCID: https://orcid.org/0000-0003-4120-1426)
- Albert F. Vong (ORCID: https://orcid.org/0000-0003-3548-6285)
- Seok Daniel Namgung (ORCID: https://orcid.org/0000-0001-6049-0433)
- S. Carin Gavin (ORCID: https://orcid.org/0000-0001-6585-2798)
- Takashi Taniguchi (ORCID: https://orcid.org/0000-0002-1467-3105)
- Tumpa Sadhukhan (ORCID: https://orcid.org/0000-0003-1995-7286)
- Kenji Watanabe (ORCID: https://orcid.org/0000-0003-3701-8119)
- Riddhi Ananth (ORCID: https://orcid.org/0000-0002-0579-8299)
- Chad Alexander Mirkin (ORCID: https://orcid.org/0000-0002-6634-7627)
- Emily A. Weiss (ORCID: https://orcid.org/0000-0001-5834-463X)
- Rafael Eduardo López-Arteaga (ORCID: https://orcid.org/0000-0001-8058-3469)
- Hongfei Zeng
- George Chappell Schatz (ORCID: https://orcid.org/0000-0001-5837-4740)
- Nathaniel P. Stern (ORCID: https://orcid.org/0000-0002-8903-3516)
- M. Iqbal Bakti Utama (ORCID: https://orcid.org/0000-0002-4454-8348)
- Andy Bennett (ORCID: https://orcid.org/0000-0003-4194-9741)
- Wei Wang (ORCID: https://orcid.org/0000-0003-3890-5561)
- Vinod K. Sangwan
- Yi Liang (ORCID: https://orcid.org/0009-0003-8401-015X)
Institutions
- Northwestern University (US)
- Argonne National Laboratory (US)
- National Institute for Materials Science (JP)
Publication Details
- Journal
- Science Advances
- Published
- 2025-10-03
- DOI
- https://doi.org/10.1126/sciadv.ady7557
- Citations
- 3
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 1.55
Funders
- U.S. Department of Energy
- Northwestern University
- Office of Science
- International Institute for Nanotechnology, Northwestern University
- Materials Research Science and Engineering Center, Northwestern University
- Japan Society for the Promotion of Science
- Division of Materials Research
- Basic Energy Sciences
- U.S. Army Combat Capabilities Development Command
- Army Research Office