标题： WS$_2$单层之间耦合的亚纳米控制与分子间隔物 显示英文标题

标题： Subnanometric control of coupling between WS$_2$ monolayers with a molecular spacer

摘要： 堆叠单层半导体形成异质结构可以控制其光学和电子性质，为纳米尺度的电子学、光电子学和光子学提供了优势。 具体而言，在单层之间添加一层薄的间隔层可以获得保留有趣单层特性的体材料，例如直接带隙和高发光量子效率。 单层之间的相互作用机制，包括层间耦合、电荷转移和能量转移，可以通过对间隔层厚度的亚纳米级控制进行调节。 传统的间隔材料如体氧化物或其他层状材料可能会在大面积上出现较差的材料界面或不均匀的厚度。 在此，我们使用旋涂有机分子间隔层来调整WS$_2$单层堆栈中的层间耦合。 我们改变分子间隔层的厚度以调节层间距离，显著改变了 resulting 有机-无机异质结构的光学性质。 此外，我们展示了价带分裂与分子间隔层厚度的依赖性，表现为由于自旋-轨道耦合和层间相互作用导致的A和B激子能量差的变化。 我们的结果说明了分子间隔层在定制单层异质结构特性方面的潜力。 这种易于实现的方法为推进原子薄器件开辟了新的途径，并可能在亚纳米尺度上实现传感技术。 显示英文摘要

摘要： Stacking monolayer semiconductors into heterostructures allows for control of their optical and electronic properties, offering advantages for nanoscale electronics, optoelectronics, and photonics. Specifically, adding a thin spacer between monolayers can yield bulk materials that retain interesting monolayer properties, such as a direct bandgap and a high emission quantum efficiency. The interaction mechanisms between monolayers, including interlayer coupling, charge transfer, and energy transfer, might be tuned through subnanometric control over the spacer thickness. Traditional spacer materials like bulk oxides or other layered materials can suffer from poor material interfaces or inhomogeneous thickness over large areas. Here, we use a spin-cast organic molecular spacer to adjust interlayer coupling in WS$_2$ monolayer stacks. We vary the molecular spacer thickness to tune the interlayer distance, significantly altering the optical properties of the resulting organic-inorganic heterostructures. Additionally, we demonstrate a dependence of the valence-band splitting on molecular spacer thickness manifested as a change in the energy difference between A and B excitons resulting from spin-orbit coupling and interlayer interactions. Our results illustrate the potential of molecular spacers to tailor the properties of monolayer heterostructures. This accessible approach opens new routes to advance atomically thin devices and could enable sensing technologies at the subnanometer scale.