Room‐Temperature Linear Electro‐Optic Response in van der Waals Ferroelectric NbOI <sub>2</sub>
ABSTRACT Two‐dimensional (2D) van der Waals (vdW) ferroelectrics offer a versatile platform for integrated electro‐optics due to their switchable polar order and strong in‐plane optical anisotropy. Despite theoretical predictions of large electro‐optic (EO) activity in Niobium oxide diiodide (NbOI 2 ), experimental evidence has remained elusive. Here, we report the experimental observation of the linear electro‐optic (LEO) effect in vdW ferroelectric NbOI 2 at the telecom wavelength of 1550 nm. Variable‐temperature Raman and second‐harmonic generation (SHG) measurements confirm that the non‐centrosymmetric polar phase remains stable up to ∼175°C. We extract an effective EO coefficient, r eff = 8.5 pm/V, which remains stable up to 10 kHz. First‐principles calculations reveal that the LEO response is intrinsically driven by the field‐induced perturbation of electron localization within Nb‐Nb dimers under a Peierls‐type distortion. These results validate NbOI 2 as a promising candidate for compact vdW optical modulators.
Authors
- 孔祥祚
- Shulin Jiao (ORCID: https://orcid.org/0000-0003-4306-4971)
- Xiaoshan Wu (ORCID: https://orcid.org/0000-0003-4200-3587)
- Yiyang Wen (ORCID: https://orcid.org/0009-0006-6433-1679)
- Zechuan Wang (ORCID: https://orcid.org/0009-0009-6351-5291)
- Zhenping Wu (ORCID: https://orcid.org/0000-0003-2986-8068)
- Haobo Shu
- Yilin Cao
- Zhang Y
- J Dai
- Fan Zhang
- Yongtao Yang
- Tingfeng Li
Institutions
- Beijing University of Posts and Telecommunications (CN)
- Nankai University (CN)
- Collaborative Innovation Center of Advanced Microstructures (CN)
Publication Details
- Journal
- Laser & Photonics Review
- Published
- 2026-05-09
- DOI
- https://doi.org/10.1002/lpor.71284
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- Fundamental Research Funds for the Central Universities