The enhancement of photovoltaic properties of the DSSCs based on D–A–π–A organic dyes via tuning auxiliary acceptor

Abstract Three novel D–A–π–A organic dyes (D1, D2, and D3) based on triarylamine donor (IDTTPA) as the electron donor and benzoic acid as the anchoring group have been successfully synthesized for dye-sensitized solar cells (DSSCs). To fine-tune absorption spectra, energy level structures, and photovoltaic properties of the target dyes, auxiliary acceptors including benzothiadiazole or diketopyrrolopyrrole units are also introduced into the dye backbones. It is found that the DPP-containing dye D3 exhibits a higher molar extinction coefficient, stronger light-capturing ability, and better photovoltaic performance than those of D1 and D2 dyes. Investigation of the photovoltaic performances shows that the D3-based DSSCs afford the highest power conversion efficiency (PCE) values of up to 5.19%, higher than those of the D1-based DSSCs (4.23%) and D2-based DSSCs (4.99%). This work has demonstrated that the incorporation of auxiliary acceptors into the IDTTPA-based organic dyes can effectively manipulate absorption band, charge recombination, and photovoltaic peformance of DSSCs.