标题： 混合弗伦克尔-瓦尼尔激子在二维有机界面促进超快能量转移 显示英文标题

标题： Hybrid Frenkel-Wannier excitons facilitate ultrafast energy transfer at a 2D-organic interface

摘要： 二维过渡金属二硫属化物（TMDs）和有机半导体（OSCs）已成为下一代光电设备有前景的材料平台。 两者的结合被预测会产生新的特性，同时保留各自组分的优势。 在OSCs中，光电响应通常由局域的Frenkel型激子主导，而TMDs则包含非局域的Wannier型激子。 然而，关于混合TMD/OSC界面处激子的空间和电子特性了解较少，这些特性最终决定了跨2D-有机界面可能的能量和电荷转移机制。 在此，我们使用超快动量显微镜和多体微扰理论来阐明一种通过超快共振Förster能量转移过程形成的混合激子。 我们表明这种混合激子既有Frenkel型又有Wannier型贡献： 在OSC层内的层内和跨TMD/OSC界面的层间电子-空穴跃迁分别导致具有混合Frenkel-Wannier特性的激子波函数。 通过理论与实验的结合，我们的工作提供了之前无法获得的关于TMD/OSC界面处混合激子本质的见解。 因此，为深入理解跨2D-有机异质结构的电荷和能量转移过程铺平了道路。 显示英文摘要

摘要： Two-dimensional transition metal dichalcogenides (TMDs) and organic semiconductors (OSCs) have emerged as promising material platforms for next-generation optoelectronic devices. The combination of both is predicted to yield emergent properties while retaining the advantages of their individual components. In OSCs the optoelectronic response is typically dominated by localized Frenkel-type excitons, whereas TMDs host delocalized Wannier-type excitons. However, much less is known about the spatial and electronic characteristics of excitons at hybrid TMD/OSC interfaces, which ultimately determine the possible energy and charge transfer mechanisms across the 2D-organic interface. Here, we use ultrafast momentum microscopy and many-body perturbation theory to elucidate a hybrid exciton at an TMD/OSC interface that forms via the ultrafast resonant F\"orster energy transfer process. We show that this hybrid exciton has both Frenkel- and Wannier-type contributions: Concomitant intra- and interlayer electron-hole transitions within the OSC layer and across the TMD/OSC interface, respectively, give rise to an exciton wavefunction with mixed Frenkel-Wannier character. By combining theory and experiment, our work provides previously inaccessible insights into the nature of hybrid excitons at TMD/OSC interfaces. It thus paves the way to a fundamental understanding of charge and energy transfer processes across 2D-organic heterostructures.