Low‐Symmetry Van der Waals Dielectric GaInS3 Triggered 2D MoS2 Giant Anisotropy via Symmetry Engineering

• Published in: Advanced materials (Weinheim) 2024-11, Vol.36 (46), p.e2410469-n/a
• Main Authors: Sun, Zongdong, Liu, Jie, Xu, Yongshan, Xiong, Xiong, Li, Yuan, Wang, Meihui, Liu, Kailang, Li, Huiqiao, Wu, Yanqing, Zhai, Tianyou
• Format: Article
• Language: English
• Subjects: anisotropic conductance; Anisotropy; Charge density; Deformation effects; dielectrics; Field effect transistors; GaInS3; Modulation; Molybdenum disulfide; MoS2/GaInS3 heterojunction; Optoelectronic devices; polarization‐sensitive photodetector; Semiconductor devices; Symmetry; symmetry engineering; Transition metal compounds
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202410469

Low‐symmetry structures in van der Waals materials have facilitated the advancement of anisotropic electronic and optoelectronic devices. However, the intrinsic low symmetry structure exhibits a small adjustable anisotropy ratio (1–10), which hinders its further assembly and processing into high‐performance devices. Here, a novel 2D anisotropic dielectric, GaInS3 (GIS), which induces isotropic MoS2 to exhibit significant anisotropic optical and electrical responses is demonstrated. With the excellent gate modulation ability of 2D GIS (dielectric constant k ∼12), MoS2 field effect transistor (FET) shows an adjustable conductance ratio from isotropic to anisotropic under dual‐gate modulation, up to 106. Theoretical calculations indicate that anisotropy originates from lattice mismatch‐induced charge density deformation at the interface. Moreover, the MoS2/GIS photodetector demonstrates high responsivity (≈4750 A W−1) and a large dichroic ratio (≈167). The anisotropic van der Waals dielectric GIS paves the way for the development of 2D transition metal dichalcogenides (TMDCs) in the fields of anisotropic photonics, electronics, and optoelectronics. The low‐symmetry dielectrics GaInS3 sparks MoS2 obvious anisotropy, at the inface of MoS2/GaInS3 heterojunction. The anisotropic optical responses are confirmed through polarized Raman and PL spectra. Under dual‐gate modulation, MoS2 FET demonstrates highly adjustable anisotropic conductivity up to 106. Remarkably, the GaInS3‐gated MoS2 photodetector exhibits a large dichroic ratio (≈167), which greatly promotes its application in polarized photodetection.