Optoelectronic properties of higher acenes, their BN analogue and substituted derivatives

Abstract

We have investigated optoelectronic properties of higher acenes: pentacene, hexacene, heptacene,octacene, nonacene, decacene and their boron-nitride (BN) analogues, within the framework of densityfunctional theory (DFT). We have also investigated the optoelectronic properties of acenes modified byBN substitution. Calculated optoelectronic properties encompasses: oxidation and reduction potentials,electron and hole reorganization energies and energy difference between excited first singlet and tripletstates DE(S1T1). Oxidation and reduction potentials indicate significantly better stability of BN analogues,comparing with their all-carbon relatives. Although higher acenes possess lower electron andhole reorganization energies, with both best values much lower than 0.1 eV, their BN analogues also havecompetitive values of reorganization energies, especially for holes for which reorganization energy is alsolower than 0.1 eV. On the other hand DE(S1T1) is much better for BN analogues, having values thatindicate that BN analogues are possible applicable for thermally activated delayed fluorescence.