Engineering Interlayer Electron-Phonon Coupling in WS 2 /BN Heterostructures.
Yifei LiXiaowei ZhangJinhuan WangXiaoli MaJin-An ShiXiangdong GuoYonggang ZuoRuijie LiHao HongNing LiKai XuXinyu HuangHuifeng TianYing YangZhixin YaoPeiChi LiaoXiao LiJunjie GuoYuang HuangPeng GaoLifen WangXiaoxia YangQing DaiEnGe WangKai-Hui LiuWu ZhouXiaohui YuLiangbo LiangYing JiangXin-Zheng LiLei LiuPublished in: Nano letters (2022)
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 WS 2 /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 WS 2 /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.