Interfacial Configuration Engineering in Organic/2D Heterostructures for Tailored Exciton Dynamics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Van der Waals (vdW) heterostructures merge organic materials and 2D transition metal dichalcogenides (TMCs) for advanced optoelectronic applications.
• Current research focuses on material combinations, but universal interfacial mechanisms remain unclear.

Purpose of the Study:

• To investigate how interfacial effects dictate configuration and modulate light-matter interactions in organic/2D TMC heterostructures.
• To demonstrate controlled epitaxial growth for programming exciton pathways.

Main Methods:

• Controlled epitaxial growth of vanadyl phthalocyanine (VOPc) on tungsten diselenide (WSe2).
• Analysis of deposition kinetics, adsorbate dipole moments, and local symmetry breaking.
• Characterization and calculations of interfacial configurations and exciton dynamics.
• Temperature-dependent studies of interlayer energy transfer.

Main Results:

• VOPc growth on WSe2 reversibly transitions between layered and acicular forms, driven by dual coupling.
• Face-to-face VOPc/WSe2 configuration shows ultrafast recombination (757 fs), 11.7x faster than edge-to-edge WSe2/VOPc (8887 fs).
• Superior photogenerated carrier separation and transport observed in VOPc/WSe2.
• Thermally activated interlayer energy transfer confirmed.

Conclusions:

• Interfacial configuration engineering is crucial for tailoring exciton dynamics in organic/2D TMC heterostructures.
• Controlled growth offers a pathway to customized functionalities and improved device performance.