Excitons can be trapped by moiré potentials in van der Waals (vdW) heterostructures, forming ordered arrays of quantum dots. Excitons can also be trapped by defect potentials as single photon emitters. While the moiré and defect potentials in vdW heterostructures have been studied separately, their interplay remains largely unexplored. Here, we perform first-principles calculations to elucidate the interplay of the two potentials in determining the optoelectronic properties of twisted MoS₂/WS₂ heterobilayers. The binding energy, charge density, localization, and hybridization of the moiré excitons can be modulated by the competition and cooperation of the two potentials. Their interplay can also be tuned by vertical electric fields, which can either de-trap the excitons or strongly localize them. One can further tailor the interplay of the two potentials via defect engineering to create one-dimensional exciton lattices with tunable orientations. Our work establishes defect engineering as a promising strategy to realize on-demand optoelectronic responses.

激子可以被范德华 (vdW) 异质结构中的莫尔势能俘获，形成有序的量子点阵列。激子也可以作为单光子发射器被缺陷电位捕获。虽然已经分别研究了 vdW 异质结构中的摩尔纹和缺陷电位，但它们的相互作用在很大程度上仍未得到探索。在这里，我们进行第一性原理计算，以阐明在确定扭曲的 MoS ₂ /WS ₂的光电特性时两种电位的相互作用异质双层。莫尔激子的结合能、电荷密度、定位和杂化可以通过两种电位的竞争和合作来调节。它们的相互作用也可以通过垂直电场进行调整，这可以解除激子的陷阱或对其进行强定位。可以通过缺陷工程进一步调整两种电位的相互作用，以创建具有可调取向的一维激子晶格。我们的工作将缺陷工程确立为实现按需光电响应的有前途的策略。