Diboron-Doped Perylene-Based Polycyclic Aromatic Hydrocarbons for Enhancing Charge Transport: A Theoretical Perspective

The enhancement of the optoelectronic properties of organic conjugation materials through boron doping may reshape current understanding, with boron-doped polycyclic aromatic hydrocarbons (PAHs) poised to be high-performance organic optoelectronic materials. However, the impact of boron doping on charge transport remains underexplored. In this study, the effects of diboron doping, including both dense and dispersed doping, along with further π-extension on the electronic structure, stacking pattern, and charge transport of perylene-based PAHs were systematically investigated using density-functional theory. The results indicate that diboron doping can switch the molecular packing from herringbone to π-stacking, which increases the transfer integrals and significantly improves the mobility. Furthermore, it is revealed that intermolecular B···B and B···C interactions promote the formation of π-π stacking by symmetry-adapted perturbation theory and Hirshfeld surface analysis. In addition, densely doped B₂-TBPA exhibits a one-dimensional intrinsic hole mobility of up to 40.86 cm² V^-1 s^-1, while B₂-HBP with π-extension and dispersed diboron doping exhibits pitched-π stacking, allowing it to display potential for bipolar transport. Monte Carlo and molecular dynamics simulations further demonstrate that diboron-doped PAHs offer more stable charge transport with reduced thermal disorder. This research provides new insights for the experimental design and synthesis of high-performance organic semiconductor devices.