Quantitative Prediction of Anisotropic Carrier Mobilities for BN-Embedded Perylene Diimides in Three-Dimensional Space

Abstract

Herein, we systematically studied the electronic structures and conducting properties of BN-embedded perylene diimides (B2N2-PDIs): 6-CH, 6-EH, and 6-DIPP reported by Wang et al. (J. Am. Chem. Soc.2022, 144, 3091–3098) and discussed the influences of partially substituting C–C units of the π-electron core with B–N units on the reorganization energies associated with hole-transport (λh) and electron-transport (λe) process, ionization potential, and electron affinity of PDIs. Our calculations revealed that the incorporation of B–N units lowered the λe by 4–9%, while the electron affinity of PDI is almost unaffected. Just as PDIs, B2N2-PDIs have the potential to be developed as high-efficiency n-type organic semiconducting materials. Furthermore, we simulated the three-dimensional angular resolution anisotropic mobility of 6-CH, 6-EH, and 6-DIPP for the first time. It is found that 6-EH and 6-CH exhibit typical n-type charge carrier-transport properties with a mobility of up to 1.45 and 0.31 cm2 V–1 s–1, respectively. The predicted anisotropic mobility range for 6-EH is consistent with the reported mobility in organic field-effect transistor devices. Moreover, 6-DIPP possesses excellent intrinsic hole mobility, and its highest mobility can be reached up to 107 cm2 s–1 V–1 due to the small λh value and strong electronic coupling between substituents of 2,6-diisopropylphenyl.