A map of high-mobility molecular semiconductors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Physical Chemistry

Background:

• Charge mobility in molecular semiconductors is often limited by dynamic disorder.
• This disorder arises from fluctuations in intermolecular transfer integrals, causing transient localization.
• Understanding this phenomenon is crucial for designing efficient organic electronic devices.

Purpose of the Study:

• To investigate the relationship between a molecular crystal's electronic structure and its sensitivity to intermolecular fluctuations.
• To identify specific patterns in transfer integrals that enhance charge mobility.
• To provide a framework for designing new molecular semiconductors with improved transport properties.

Main Methods:

• Utilized a recently developed theoretical framework to analyze electronic structures.
• Developed a map of transient localization lengths for high-mobility molecular semiconductors.
• Identified patterns of nearest-neighbor transfer integrals in 2D high-mobility planes.

Main Results:

• Electronic structure dictates sensitivity to intermolecular fluctuations.
• Specific patterns of transfer integrals protect semiconductors from dynamic disorder, increasing mobility.
• A map was created to visualize these protective patterns in 2D high-mobility planes.

Conclusions:

• The study rationalizes transport properties of molecular semiconductors.
• Highlights limitations of common textbook approaches for this material class.
• Provides a method for screening and designing high-performance molecular semiconductors.