Variety of Ordered Patterns in Donor-Acceptor Polymer Semiconductor Films Crystallized from Solution

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Controlling crystallite nucleation during polymer film formation is crucial for desired structures.
• Donor-acceptor polymer semiconductors like P(NDI2OD-T2) are vital for organic electronics.

Purpose of the Study:

• To investigate polymer crystallization control using controlled solution flow.
• To explore the relationship between film morphology and charge transport properties.

Main Methods:

• Utilized a seesaw-like pivoting technique during polymer drying to control solution flow.
• Investigated P(NDI2OD-T2) crystallization by varying pivoting frequency and amplitude.
• Fabricated thin-film transistors to measure charge mobility.

Main Results:

• Achieved controlled formation of various line patterns: fishbone-like stripes, PDCL-defined wires, and twined crystalline lines.
• Attributed diverse pattern formation to the unique donor-acceptor conjugated polymer structure.
• Observed that charge mobility of P(NDI2OD-T2) is largely independent of film morphology.

Conclusions:

• Pivoting-induced solution flow offers a method for patterning conjugated polymer films.
• The findings contribute to understanding charge transport mechanisms in donor-acceptor polymer semiconductors.
• Morphological insensitivity of charge mobility supports ongoing debates in the field.