Engineering Interlayer Electron–Phonon Coupling in WS<sub>2</sub>/BN Heterostructures
Yifei Li, Xiaowei Zhang, Jinhuan Wang, Xiaoli Ma, Jinan Shi, Xiangdong Guo, Yonggang Zuo, Ruijie Li, Hao Hong, Ning Li, Kai Xu, Xinyu Huang, Huifeng Tian, Ying Yang, Zhixin Yao, PeiChi Liao, Xiao Li, Xiao Li, Junjie Guo, Yuang Huang, Peng Gao, Lifen Wang, Xiaoxia Yang, Qing Dai, Enge Wang, Kaihui Liu, Wu Zhou, Xiaohui Yu, Liangbo Liang, Ying Jiang, Xin-Zheng Li, Xin-Zheng Li, Lei Liu
Abstract
In van der Waals (vdW) heterostructures, the interlayer electron–phonon coupling (EPC) provides one unique channel to nonlocally engineer these elementary particles. However, limited by the stringent occurrence conditions, the efficient engineering of interlayer EPC remains elusive. Here we report a multitier engineering of interlayer EPC in WS2/boron nitride (BN) heterostructures, including isotope enrichments of BN substrates, temperature, and high-pressure tuning. The hyperfine isotope dependence of Raman intensities was unambiguously revealed. In combination with theoretical calculations, we anticipate that WS2/BN supercells could induce Brillouin-zone-folded phonons that contribute to the interlayer coupling, leading to a complex nature of broad Raman peaks. We further demonstrate the significance of a previously unexplored parameter, the interlayer spacing. By varying the temperature and high pressure, we effectively manipulated the strengths of EPC with on/off capabilities, indicating critical thresholds of the layer–layer spacing for activating and strengthening interlayer EPC. Our findings provide new opportunities to engineer vdW heterostructures with controlled interlayer coupling.