Two-dimensional (2D) WS₂ films were deposited on SiO₂ wafers, and the related interfacial properties were investigated by high-resolution X-ray photoelectron spectroscopy (XPS) and first-principles calculations. Using the direct (indirect) method, the valence band offset (VBO) at monolayer WS₂/SiO₂ interface was found to be 3.97 eV (3.86 eV), and the conduction band offset (CBO) was 2.70 eV (2.81 eV). Furthermore, the VBO (CBO) at bulk WS₂/SiO₂ interface is found to be about 0.48 eV (0.33 eV) larger due to the inter-layer orbital coupling and splitting of valence and conduction band edges. Therefore, the WS₂/SiO₂ heterostructure has a Type I energy-band alignment. The band offsets obtained experimentally and theoretically are consistent except the narrower theoretical bandgap of SiO₂. The theoretical calculations further reveal a binding energy of 75 meV per S atom and the totally separated partial density of states, indicating a weak interaction and negligible Fermi level pinning effect between WS₂ monolayer and SiO₂ surface. Our combined experimental and theoretical results provide proof of the sufficient VBOs and CBOs and weak interaction in 2D WS₂/SiO₂ heterostructures.

将二维（2D）WS ₂薄膜沉积在SiO ₂晶片上，并通过高分辨率X射线光电子能谱（XPS）和第一性原理计算研究了相关的界面性质。使用直接（间接）方法，发现单层WS ₂ /SiO ₂界面的价带偏移（VBO）为3.97 eV（3.86 eV），导带偏移（CBO）为2.70 eV（2.81 eV）。此外，由于层间轨道耦合以及价带和导带边缘的分裂，发现体 WS ₂ /SiO ₂界面处的 VBO (CBO)大约大 0.48 eV (0.33 eV)。因此，WS ₂ /SiO ₂异质结构具有 I 型能带排列。_{除了SiO 2}的较窄理论带隙外，实验和理论上获得的带偏移是一致的。理论计算进一步揭示了每个S原子75 meV的结合能和完全分离的部分状态密度，表明WS ₂单层和SiO ₂表面之间的弱相互作用和可忽略的费米能级钉扎效应。我们结合实验和理论结果提供了足够的 VBO 和 CBO 以及二维 WS ₂ /SiO ₂异质结构中的弱相互作用的证据。