Millimeter-Sized Two-Dimensional Molecular Crystalline Semiconductors with Precisely Defined Molecular Layers via...

Area of Science:

• Organic electronics
• Materials science
• Surface science

Background:

• Controlling molecule-substrate interfaces is crucial for 2D organic electronics.
• Achieving ordered 2D molecular crystalline films requires precise control over assembly.

Purpose of the Study:

• To demonstrate thermally induced self-assembly of 2D organic crystalline films.
• To control molecular layer number and achieve large-area uniformity using van der Waals interactions.

Main Methods:

• Exploiting molecule-substrate van der Waals (vdW) interactions.
• Utilizing thermal energy to drive self-assembly processes.
• Fabricating organic field-effect transistors (OFETs) to evaluate film performance.

Main Results:

• Achieved self-assembly of 2D organic crystalline films with controlled molecular layers over millimeter-sized areas.
• OFETs with bilayer films demonstrated high electrical performance (max mobility 12.8 cm² V⁻¹ s⁻¹).
• Monolayer films served as templates for heterojunctions with balanced ambipolar transport.

Conclusions:

• Thermally induced self-assembly enables controllable 2D molecular crystalline films with scalable coverage.
• This approach facilitates complex electronic applications like lateral heterojunctions and superlattices.