Homogeneously Oriented Organic Single-Crystalline Patterns Grown by Microspacing In-Air Sublimation

Area of Science:

• Materials Science
• Organic Electronics
• Crystallography

Background:

• Fabricating single-crystalline organic semiconductor patterns is vital for practical applications.
• Controlling nucleation and achieving homogeneous orientation in vapor-grown single-crystals remains a significant challenge.

Purpose of the Study:

• To develop a vapor growth protocol for patterned organic semiconductor single-crystals with high crystallinity and uniform crystallographic orientation.
• To overcome limitations in controlling isolated crystal patterns on non-epitaxial substrates.

Main Methods:

• Utilized microspacing in-air sublimation with surface wettability treatment for precise molecular pinning.
• Employed inter-connecting pattern motifs to induce homogeneous crystallographic orientation.
• Demonstrated the protocol using 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT).

Main Results:

• Achieved patterned organic semiconductor single-crystals with high crystallinity and uniform orientation.
• Fabricated single-crystalline patterns of varying shapes and sizes.
• Demonstrated uniform electrical performance in field-effect transistor arrays with 100% yield and average mobility of 6.28 cm² V⁻¹ s⁻¹.

Conclusions:

• The developed protocol enables precise control over organic single-crystal pattern fabrication via vapor methods.
• This advancement facilitates the alignment of anisotropic electronic properties for large-scale device integration.
• The method overcomes previous challenges in vapor growth on non-epitaxial substrates.