Orienting and shaping organic semiconductor single crystals through selective nanoconfinement

Area of Science:

• Materials Science
• Organic Electronics
• Nanotechnology

Background:

• Organic semiconductors exhibit anisotropic charge transport.
• Nanoconfinement offers a method to control crystal orientation.
• Crystal growth habits influence charge transport properties.

Purpose of the Study:

• To establish design rules for controlling organic semiconductor crystal morphology and orientation using nanoconfining scaffolds.
• To investigate the relationship between scaffold geometry and crystal growth.
• To explore the formation of complex crystal shapes through controlled nanoconfinement.

Main Methods:

• Solution processing of organic semiconductor crystals (triisopropylsilylethynyl pyranthrene and perylene) within nanoconfining scaffolds.
• Utilizing cylindrical nanopores (m=1) and nanopillar arrays (m=2) as scaffolds.
• Comparing crystal growth in scaffolds with matching (n=m) and differing (n≠m) dimensionalities.

Main Results:

• Scaffold geometry dictates crystal orientation when dimensionality matches (n=m).
• For differing dimensionalities (n≠m), orientation control is planar (parallel or perpendicular to the substrate).
• Perylene crystals grown in cylindrical nanopores (n>m) exhibited shape control, forming T-shaped single crystals.

Conclusions:

• Nanoconfinement provides precise control over organic crystal orientation and morphology.
• Spatially varying scaffold dimensionalities enable the growth of single crystals with complex shapes.
• This strategy is crucial for optimizing charge transport in organic electronic devices.