Electronic conductivity in polyaromatic hydrocarbon glasses: A theoretical perspective

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Amorphous molecular glasses and polyaromatic hydrocarbons are crucial in organic electronics.
• Understanding charge transport in these materials is key to device performance.
• Existing models require refinement for disordered organic systems.

Purpose of the Study:

• To compute the electronic structure of five prototypical polyaromatic hydrocarbons within amorphous molecular glasses.
• To analyze charge transfer processes and determine local and global conductivities.
• To correlate conductivity with the structural characteristics of the disordered materials.

Main Methods:

• Monte Carlo simulations for amorphous molecular glass structures.
• Extended Su-Schrieffer-Heeger model for electronic structure calculations.
• Marcus theory of charge transfer and linear response theory for conductivity analysis.
• Kirchhoff's rules applied to a random resistor network model.

Main Results:

• Calculated electronic structures for five polyaromatic hydrocarbons in disordered environments.
• Determined reaction coefficients and local conductivities based on charge transfer theory.
• Derived global conductivities in the range of 10^-1 to 1 S/cm.
• Established a correlation between global conductivity and the underlying geometric structure.

Conclusions:

• The study provides a computational framework for predicting charge transport in amorphous organic materials.
• Global conductivity is significantly influenced by the specific structural arrangements of polyaromatic hydrocarbons.
• Findings offer valuable insights for designing and optimizing organic electronic devices.