近日，德国哥廷根大学Stefan Mathias团队揭示了杂化的Frenkel-Wannier激子促进了二维有机界面上的超快能量传递。相关论文于2025年10月29日发表在《自然—物理学》杂志上。
二维过渡金属二硫族化合物和有机半导体已成为光电子器件有前景的材料平台。预计将两者结合在一起将产生关键属性，同时保留各自的优势。在有机半导体中，光电响应通常由局域化的frenkel型激子主导，而过渡金属二硫族化合物则有局域化的wannier型激子。然而，人们对这些材料之间的杂化界面上的激子的特性知之甚少，这些特性决定了可能的能量和电荷转移途径。
研究组使用超快动量显微镜和多体微扰理论在一个这样的界面上识别出一个混合激子。结果发现，这种主要通过共振Förster能量转移形成的混合激子具有Frenkel和Wannier型贡献：有机半导体层内的层内电子-空穴跃迁和界面上的层间跃迁产生了具有混合特征的激子波函数。这项工作推进了人们对二维有机异质结构中电荷和能量转移过程的理解。
附：英文原文
Title: Hybrid Frenkel–Wannier excitons facilitate ultrafast energy transfer at a 2D–organic interface
Author: Bennecke, Wiebke, Gonzalez Oliva, Ignacio, Bange, Jan Philipp, Werner, Paul, Schmitt, David, Merboldt, Marco, Seiler, Anna M., Watanabe, Kenji, Taniguchi, Takashi, Steil, Daniel, Weitz, R. Thomas, Puschnig, Peter, Draxl, Claudia, Jansen, G. S. Matthijs, Reutzel, Marcel, Mathias, Stefan
Issue&Volume: 2025-10-29
Abstract: Two-dimensional transition metal dichalcogenides and organic semiconductors have emerged as promising material platforms for optoelectronic devices. Combining the two is predicted to yield emergent properties while retaining the advantages of each. In organic semiconductors, the optoelectronic response is typically dominated by localized Frenkel-type excitons, whereas transition metal dichalcogenides host delocalized Wannier-type excitons. However, much less is known about the characteristics of excitons at hybrid interfaces between these materials, which determine the possible energy- and charge-transfer pathways. Here we identify a hybrid exciton at one such interface using ultrafast momentum microscopy and many-body perturbation theory. We show that this hybrid exciton, formed predominantly via resonant Frster energy transfer, has both Frenkel- and Wannier-type contributions: intralayer electron–hole transitions within the organic semiconductor layer and interlayer transitions across the interface give rise to an exciton wavefunction with mixed character. This work advances our understanding of charge and energy transfer processes across 2D–organic heterostructures.
DOI: 10.1038/s41567-025-03075-5
Source: https://www.nature.com/articles/s41567-025-03075-5