Title: Air-stable and high mobility based electron transport semiconducting material hexachloro- hexa-azatrinaphthylene

Abstract

In the last few years, organic semiconductors (OSCs) have attracted a considerable amount of attention due to their wide potential applications in various electronic devices such as organic field-effect transistors (OFETs), organic photovoltaic devices (OPVs), organic light- emitting diodes (OLEDs), and organic solar cells (OSCs). Unlike their inorganic counterparts, organic semiconducting materials are cost-effective, lightweight, and flexible and provide the versatility of chemical synthesis. However, one of the major challenges for the development and fabrications of organic semiconductors for industrial applications is their air instabilities. From the theoretical point of view, the air-stability of the organic semiconducting material depends upon its low-lying frontier molecular orbitals and the energy gap in between them. A new n-type organic semiconductor based on the haxachloro-hexaaza-trinaphthylene compound is reported. The electronic structure and charge transport properties of the compound is calculated in the framework of density functional theory (DFT). The electron- withdrawing group (-Cl) on the end position of the compound could help to lower the LUMO energy level and improve the air-stability and charge carrier mobility. The large electron affinity (2.60 eV) and low LUMO energy (-3.63 eV) suggests that the compounds were to be air-stable and N-type organic semiconductor. Moreover, lower values of the electron- injection barrier as compared to those of the hole-injection barrier implied that the investigated compounds were basically N-type semiconductors. The computed electronic coupling of LUMO of the compound was found to be comparatively larger in the transverse- channel (86.6 meV) than other channels. The computed large electron and hole mobility was found to be 3.54 cm2V-1s-1 and 0.014 cm2V-1s-1. Further, Hirshfeld analysis depicting the distribution of surface charge in between the molecular layers of the crystals revealed that the principal interactions were mostly due to the Cl…H/H…Cl and Cl…Cl contacts of the compounds.