Giant Light Emission Enhancement in Strain-Engineered InSe/MS<sub>2</sub> (M = Mo or W) van der Waals Heterostructures
Two-dimensional (2D) heterostructures (HSs) offer unlimited possibilities for playing with layer number, order, and twist angle. The realization of high-performance optoelectronic devices, however, requires the achievement of specific band alignments, <i>k</i>-space matching between conduction and valence band extrema, and efficient charge transfer between the constituent layers. Fine-tuning mechanisms to design ideal HSs are lacking. Here, we show that layer-selective strain engineering can be exploited as an extra degree of freedom to tailor the band alignment and optical properties of 2D HSs. To that end, strain is selectively applied to MS<sub>2</sub> (M = Mo or W) monolayers in InSe/MS<sub>2</sub> HSs, triggering a giant photoluminescence enhancement of the highly tunable but weakly emitting InSe of up to >2 orders of magnitude. Resonant excitation measurements, supported by first-principles calculations, provide evidence of a strain-activated charge transfer from the MS<sub>2</sub> monolayers toward InSe. The huge emission enhancement of InSe widens its range of applications for optoelectronics.
Authors
- Maurizia Palummo (ORCID: https://orcid.org/0000-0002-3097-8523)
- Michele Re Fiorentin (ORCID: https://orcid.org/0000-0002-1074-0411)
- A. Patanè (ORCID: https://orcid.org/0000-0003-3015-9496)
- Takashi Taniguchi (ORCID: https://orcid.org/0000-0002-1467-3105)
- Z. R. Kudrynskyi (ORCID: https://orcid.org/0000-0003-3983-9316)
- Elena Blundo (ORCID: https://orcid.org/0000-0003-0423-4798)
- Kenji Watanabe (ORCID: https://orcid.org/0000-0003-3701-8119)
- Marco Felici (ORCID: https://orcid.org/0000-0002-0977-2301)
- Giorgio Pettinari (ORCID: https://orcid.org/0000-0003-0187-3770)
- Federico Tuzi (ORCID: https://orcid.org/0009-0000-8887-5706)
- Salvatore Cianci (ORCID: https://orcid.org/0000-0003-4020-369X)
- A. Polimeni (ORCID: https://orcid.org/0000-0002-2017-4265)
- Marzia Cuccu (ORCID: https://orcid.org/0009-0001-0264-063X)
- Atanu Patra (ORCID: https://orcid.org/0000-0002-8151-7997)
Institutions
- University of Rome Tor Vergata (IT)
- University of Nottingham (GB)
- Politecnico di Torino (IT)
- National Institute for Materials Science (JP)
- Faculty (United Kingdom) (GB)
- Engineering (Italy) (IT)
- Center for Biomolecular Nanotechnologies (IT)
- National Research Council (IT)
- Sapienza University of Rome (IT)
Publication Details
- Journal
- Nano Letters
- Published
- 2025-02-05
- DOI
- https://doi.org/10.1021/acs.nanolett.4c04252
- Citations
- 6
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 3.11
Funders
- European Commission
- Ministry of Education, Culture, Sports, Science and Technology
- Consiglio Nazionale delle Ricerche
- QuantERA
- Ministero dell'Università e della Ricerca
- Horizon 2020 Framework Programme
- Japan Society for the Promotion of Science