Design of a New Molecule by Application of Functionalizing CTF-۰ with DBT Units to Enhance the Performance of the Acceptor Layer in Organic Solar Cells

This study aims to design new molecules based on the functionalization of CTF-۰ with one, two, and DBT units, and investigate novel non-fullerene acceptor molecules to enhance their performance. The DFT and TD-DFT calculations using the LSDA functional and the ۶-۳۱G(d,p) basis set were employed to analyze structural changes, the energy gap, the dipole moment, and the optical absorption spectra. Additionally, the photovoltaic performance parameters of organic solar cells based on these molecules were evaluated and compared in solvent media using different donor-acceptor combinations, including well-known donors PM۶ and PM۷, as well as CTF۰ as a proposed donor paired with the designed acceptors. The computational results in a solvent medium reveal that increasing the number of DBT units significantly reduces the energy gap from ۲.۸۶ to ۱.۹۶ eV and induces a pronounced redshift in absorption from ۳۹۹ to ۵۶۷ nm, indicating improved visible-light harvesting. Furthermore, the dipole moment increased up to ۲.۸۵ D, suggesting enhanced electron-hole separation. Among the studied systems, the highest Power Conversion Efficiency (PCE) of ۲۴.۱۷% was achieved for the CTF۰: R-۳DBT system, demonstrating the high potential of the designed molecules for efficient organic photovoltaics. This research highlights the novelty of new molecular design through DBT functionalization via theoretical study, paving the way for the development of more efficient acceptor materials in organic solar cells.

کلیدواژه ها:

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