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Abstract：
Manipulation of excitonic emission in two-dimensional (2D) materials via the assembly of van der Waals (vdW) heterostructures unlocks numerous opportunities for engineering their photonic and optoelectronic properties. In this work, we introduce a category of mixed-dimensional vdW heterostructures, integrating 2D materials with one-dimensional (1D) semiconductor nanowires composed of vdW layers. This configuration induces spatially distinct localized excitonic emissions through a tailored interfacial heterolayer atomic arrangement. By precisely adjusting both the axial and sidewall facet orientations of bottom-up grown PbI2 vdW nanowires and by transferring them onto 1L WSe2 flakes, we establish vdW heterointerfaces with either perpendicular or parallel interatomic arrangements. The edge-standing heterojunction, featuring perpendicular PbI2 layers atop WSe2, promotes efficient charge transfer through the edges and coupled localized states, leading to an enhanced redshifted excitonic emission. Conversely, the layer-by-layer heterointerface, where PbI2 layers are in parallel contact with WSe2, exhibits substantial quenching due to deep midgap states in a type-II alignment, as evidenced by power-dependent measurements and first-principle calculations. Our results introduce a method for actively manipulating excitonic emissions in 2D transition metal dichalcogenides (TMDs) through edge engineering, highlighting their potential in the development of various quantum devices.
摘要：
通过范德华（vdW）异质结构的组装来操纵二维（2D）材料中的激子发射为设计其光子和光电特性提供了许多机会。在这项工作中,我们介绍一类混合维vdW异质结构，将2D材料与由vdW层组成的一维(1D)半导体纳米线集成。这种构型通过定制的界面异质层原子排列诱导空间上不同的局部激子发射。通过精确调整自下而上生长的PbI2vdW纳米线的轴向和侧壁刻面取向，并将它们转移到1LWSe2薄片上，我们建立了具有垂直或平行原子间排列的vdW异质界面。边缘站立的异质结，在WSe2上具有垂直的PbI2层，促进通过边缘和耦合局部状态的有效电荷转移，导致增强的红移激子发射。相反，逐层异质界面，其中PbI2层与WSe2平行接触，由于II型排列中的深中隙状态而表现出实质性的猝灭，功率相关测量和第一原理计算证明了这一点。我们的结果介绍了一种通过边缘工程主动操纵2D过渡金属二硫属化合物（TMD）中的激子发射的方法，突出了它们在各种量子器件开发中的潜力。
