Predicting properties of organic optoelectronic materials: asymptotically corrected density functional study

Area of Science:

• Computational materials science
• Organic electronics
• Polymer physics

Background:

• Organic optoelectronic materials require precise electronic parameters for optimal performance.
• Predicting these properties computationally is crucial for material design and selection.

Purpose of the Study:

• To develop a practical computational procedure for determining key electronic parameters of polymers.
• To assess the suitability of polymers as donor or acceptor materials in organic optoelectronics.
• To identify promising polymer-based donor-acceptor combinations.

Main Methods:

• Utilized oligomer calculations at the Becke3-Lee-Yang-Parr (B3LYP) level with a 6-31G** basis set.
• Employed a self-contained asymptotic correction to improve accuracy.
• Extrapolated polymer properties (bandgap, ionization energy, electron affinity) from oligomer data using Koopmans-like approximation.
• Applied the scheme to poly(p-phenylene), poly(thiophene), poly(pyrrole) backbones, and PCBM.

Main Results:

• The computational scheme reproduced observed electronic parameters within 1 eV for most cases.
• Predicted parameters allowed estimation of open-circuit voltage and drift potential for 22 donor-acceptor combinations.
• Identified several potentially useful combinations, notably poly(thiophene):PCBM.
• Electron and hole mobilities correlated more strongly with polymer planarity than bandgap.

Conclusions:

• The proposed computational method offers a practical way to predict essential electronic properties of polymers for optoelectronic applications.
• The study successfully identified promising donor-acceptor material combinations.
• Conformation plays a significant role in charge carrier mobility in these polymers.