Impact of Malononitrile-Based Functionalization on Covalent Triazine Framework Derivatives for High-Performance Organic Solar Cells

This research explores the structural and electronic characteristics of novel CTF-۰ derivatives (R-۱MDC, R-۲MDC, and R-۳MDC) as potential non-fullerene acceptors for organic solar cells. Density Functional Theory and Time-Dependent DFT computations were carried out using the LSDA functional with the ۶-۳۱G (d, p) basis set under both gas-phase and chloroform solvent conditions. To evaluate the photovoltaic parameters of the designed molecules, TCNQ, a well-known standard acceptor, was used as a reference for assessing electronic performance and optimizing charge transfer properties. The incorporation of MDC groups markedly reduced the energy gap, lowering it from ۲.۸۵ eV in CTF-۰ to ۱.۶۶ eV in the solvent phase, thereby enhancing light absorption. The open-circuit voltage exhibited an increasing trend, reaching ۱.۸۶ V in R-۳MDC. The density of states and transition density matrix analyses confirmed significant improvements in charge transfer characteristics. This compound also demonstrated the power conversion efficiency of ۲۷.۴۹%, and a fill factor of ۹۲.۷۴%making it the most promising candidate. These results offer important guidance for designing efficient NFA materials with optimized electronic properties for solar energy conversion.

کلیدواژه ها:

Organic solar cell ، Non-fullerene acceptor ، MDC ، TD-DFT ، Photovoltaic properties ، Charge transfer