Interlayer Coupling in Organic‐Inorganic Heterostructures via Interfacial F···S Interactions for Near‐Infrared Photodetection and Real‐Time Motion Recognition

Abstract

ABSTRACT Interlayer coupling serves as a powerful strategy for manipulating the optoelectronic characteristics of van der Waals heterostructures. Although the combination of organic and inorganic semiconductors has enabled versatile optoelectronic applications, interlayer coupling in organic–inorganic heterostructures is still limited by inherent material discrepancies such as lattice matching and stacking order. Herein, we demonstrate an interlayer–coupled organic–inorganic heterojunction achieved by interfacial noncovalent F···S interactions, which is composed of molecular 5,5''‐bis(2‐fluorophenyl)‐2,2':5',2''‐terthiophene (oF‐PTTTP) and 2D molybdenum disulfide (MoS 2 ). By leveraging the conformational flexibility afforded by the full C─C single bonds in its backbone, the oF‐PTTTP molecules can self‐adjust their conformations upon thermal activation. The fluorine atoms on the side chains of oF‐PTTTP engage in noncovalent interactions with the sulfur atoms of MoS 2 at the heterointerface, inducing a pronounced interlayer coupling effect accompanied by lattice strain. This coupling enables near‐infrared (NIR) photodetection in a spectral range inaccessible to each individual component, yielding a specific detectivity of 1.8 × 10 14 Jones at 808 nm, which is one of the highest values reported for organic–inorganic heterostructures. Furthermore, the device exhibits gate‐tunable positive and negative photoresponses at 808 nm, allowing real‐time motion imaging in the NIR spectrum.