Electronic and optical properties of edge modified peritetracene: a DFT study

Abstract

Peritetracene (PTA) molecules have promising applications in organic electronics and organic light-emitting diodes, but the major constraints come from their poor stability with higher energy gap. We have investigated the stability, electronic, and optical properties of different electron-donating- and electron-withdrawing-substituted PTA molecule groups using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods. On substituting suitable electron donor and acceptor groups, the energy gap of PTA molecules reduces up to 0.37 eV with an increase in their stability. The stabilities of considered PTA molecules have been investigated using the distribution pattern of frontier molecular orbital energies. The charge transfer properties with smaller ionization potential and larger electron affinity for PTA molecule have been evaluated using Koopmans’ theorem. Enhancement in dipole moment, polarizability, and hyperpolarizability of PTA substituted with electron-donating groups shows the presence of NLO properties. Also, we have investigated the spectroscopic properties of different electron-donating- and electron-withdrawing-substituted PTA molecule groups. Our spectroscopic properties show the bathochromic shift and small hypsochromic shifts in wavelengths of PTA with substituents groups. It is therefore concluded that the –NCH3 and –NO2 substituent groups on PTA are observed to have the strongest and highest stability than the other substituent groups considered.