Donor-Acceptor Supramolecular Cocrystals for Tunable Optoelectronic Applications: First-Principles Quantum-Mechanical Calculations

Supramolecular charge-transfer (CT) cocrystals composed of electron donors and acceptors offer tunable electronic and optical properties for organic semiconductors. With first-principles calculations based on density-functional theory (DFT), we extend previous studies of the various cocrystals by applying both generalized gradient approximation (GGA) exchange-correlation functionals and hybrid functionals to capture bulk effects, intermolecular coupling, and the band gaps. We examine donor-acceptor (D-A) pairs with tetrachloroperylene dianhydride (TCPDA), tetracyanoquinodimethane (TCNQ), and tetrafluorotetracyanoquinodimethane (4FTCNQ) as electron-deficient acceptors, and polyaromatic hydrocarbons (PAHs) of increasing π-conjugation (e.g., triphenylene, pyrene, perylene, and coronene) along with electron-rich tetrathiafulvalene (TTF) as acceptors. Emphasis is placed on bandgap modulation, orbital charge distribution, and predicted absorption spectra across the UV–Vis–NIR range to identify candidates for efficient optoelectronic and photothermal materials. The calculated results are in good agreement with the available experimental data.