Design of (4n+2)π Cyanide Acceptor-Based 5,7,12,14-Tetraazapentacene Derivatives as Ambipolar Organic Semiconductors

Ambipolar molecules are of significant importance in the field of organic electronics and semiconductor devices primarily due to their dual charge carrier transport nature, which results in simplification of device design, enhanced device performance, tuning of electrical properties, and versatility in application. In this study, density functional theory (DFT)-based calculations are performed to examine the effects of sequential cyanation (-CN) on the adiabatic ionization potential (IP), adiabatic electron affinity (EA), reorganization energies (λ_h and λ_e), and charge transfer rate (K^≠) along with charge (hole and electron) injection possibility for a series of derivatives based on already synthesized 5,7,12,14-tetraazapentacene (N4PENT) as the core moiety. The results illustrate that introducing two or more cyanide (-CN) groups onto the N4PENT core is sufficient to induce stable ambipolar charge transport properties, trending toward n-type semiconducting character. Besides, analysis of the density of states (DOS) offers a clear understanding of how sequential cyanation affects the distribution of electron density. Overall, this study underscores a rational foundation for designing stable ambipolar organic semiconductors (OSCs), which can significantly advance organic electronics, leading to more efficient and adaptable electronic devices applicable in flexible electronics, wearable technology, and low-cost displays.