Enhanced Performance of NiO-Based Dye-Sensitized Solar Cells Using a Covalent Porphyrin-C60 Dyad

Abstract

This study presents the synthesis and the characterization of a new covalent zinc porphyrin-fullerene (ZnP-C₆₀) dyad, featuring a π-conjugated bridge to link the donor (ZnP) and the acceptor (C₆₀). This system, along with a couple more reference compounds, namely ZnP-3DoH-COOH and C₆₀trZnPCOOH, is tested as photosensitizers in p-type dye-sensitized solar cells (p-DSSCs). Photophysical studies, including absorption and emission spectroscopy, reveal strong electronic communication between the porphyrin core and the fullerene unit, corroborated by theoretical calculations demonstrating efficient electron transfer from the donor to the acceptor. Electrochemical measurements, supported by theoretical insights, confirm that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital(LUMO) energy levels of the C₆₀-3PV-ZnP-2DoH-COOH dyad are well aligned for effective integration into NiO-based DSSCs. Notably, photovoltaic performance measurements show that solar cells sensitized with the covalent dyad exhibit significantly enhanced efficiencies compared with those using the reference compounds and other “ZnP-Acceptor” dyads. These findings highlight the potential of covalent ZnPor-C₆₀ assemblies in advancing the design of high-performance p-type DSSCs.