Abstract：
The moiré potential in rotationally misfit two-dimensional (2D) heterostructures has been used to build artificial exciton and electron lattices, which have become platforms for realizing exotic electronic phases. Here, we demonstrate a different approach to create a superlattice potential in 2D crystals by using the near field of an array of polar molecules. A bilayer of titanyl phthalocyanine (TiOPc), consisting of alternating out-of-plane dipoles, is deposited on monolayer MoS2. Time-resolved two-photon photoemission spectroscopy reveals a pair of interlayer exciton states with an energy difference of ∼0.1 eV, which is consistent with the electrostatic potential modulation induced by the TiOPc bilayer as determined by density functional theory calculations. Because the symmetry and the period of this potential superlattice can be changed readily by using molecules of different shapes and sizes, molecule/2D heterostructures can be promising platforms for designing artificial exciton and electron lattices.
摘要：
旋转失配二维（2D）异质结构中的莫尔电势已用于构建人造激子和电子晶格，它们已经成为实现奇特电子阶段的平台。这里,我们展示了一种通过使用极性分子阵列的近场在2D晶体中创建超晶格电势的不同方法。钛氧基酞菁（TiOPc）的双层，由交替的平面外偶极子组成，沉积在单层MoS2上。时间分辨双光子光发射光谱揭示了一对能量差0.1eV的层间激子状态，这与通过密度泛函理论计算确定的TiOPc双层引起的静电势调制一致。因为通过使用不同形状和大小的分子可以很容易地改变这种潜在超晶格的对称性和周期，分子/2D异质结构可以成为设计人工激子和电子晶格的有前途的平台。
