A Simple Index for Characterizing Charge Transport in Molecular Materials

Area of Science:

• Materials Science
• Computational Chemistry
• Solid-State Physics

Background:

• Accurate prediction of band alignment is achievable with quantum chemistry.
• Forecasting conductivity in noncrystalline, multimolecule systems lacks a simple computational method.
• Understanding charge transport is crucial for organic electronic devices.

Purpose of the Study:

• To develop a computational index for quantifying charge transport in bulk molecular materials.
• To provide a method applicable to noncrystalline systems, removing the need for crystallinity.
• To enable a priori determination of bulk charge transport properties.

Main Methods:

• Adapting the theory of classical resistor networks.
• Developing a novel index for quantifying charge transport.
• Applying the index to simple lattices and clusters of organic photovoltaic molecules.

Main Results:

• The developed index quantifies charge transport in bulk molecular materials without requiring crystallinity.
• Application to organic photovoltaic molecules reproduced known experimental performances.
• Demonstrated the index's ability to predict charge transport behavior.

Conclusions:

• A quantitative computational method for predicting bulk charge transport in molecular materials has been established.
• This index offers a valuable tool for the a priori design and optimization of molecular materials for electronic applications.
• The approach overcomes limitations of previous methods by addressing noncrystalline systems.