Broken Valley Degeneracy in Epitaxial MoS 2 on Plasma‐Engineered AlN

作者：Yuxiang Zhang, Weiqing Tang, Haiyang Liu, Mengyu Liu, Anqi Cheng, Szu‐Yuan Wu, Ying Ye, Min Liu, Zongnan Zhang, Chunmiao Zhang, Yaping Wu, Li Xu, Zhiming Wu, Junyong Kang · 发表于：Laser & Photonics Review · 年份：2025 · DOI：10.1002/lpor.202500823 · 被引用次数：2 · 研究领域：2D Materials and Applications、MXene and MAX Phase Materials、Graphene research and applications

Abstract Two‐dimensional transition metal dichalcogenides represent a highly attractive platform for the development of valleytronic devices due to their unique spin‐valley properties. Herein, a plasma‐assisted interfacial engineering is proposed to enhance valley polarization and valley splitting in MoS 2 /AlN heterostructure by modifying the surface configurations of AlN substrates. The experimental results show that after the optimized N 2 ‐plasma treatment, the AlN surface becomes smoother with a decreased migration barrier, thereby facilitating the growth of high‐quality MoS 2 . The valley splitting and degree of valley polarization in the optimal sample reach 7.96 meV (the corresponding Landé g factor is 19.6) and 33.8% at −7 T, which are 16.0‐ and 1.0‐fold higher than those in the untreated MoS 2 /AlN heterostructure, respectively. Theoretical simulations indicate that the enhanced spin‐valley properties are predominantly ascribed to the AlN surface magnetism induced by the hybridization of P z and P y orbitals of surface N and O atoms. This work opens a new avenue for manipulating spin‐valley properties in 2D materials via interfacial engineering.