Synergistic PMMA/rGO/ZnO/Cu photoanodes for high-performance solid-state dye-sensitized solar cells

Abstract

This study reports the fabrication and evaluation of Poly(methyl methacrylate) PMMA-based hybrid composite photoanodes for solid-state dye-sensitized solar cells (DSSCs). The composites integrate reduced graphene oxide (rGO) and copper (Cu) with a ZnO nanoparticle matrix to enhance conductivity. Graphene oxide (GO), synthesized via a modified Hummers method, was reduced to rGO, while ZnO nanoparticles were prepared by chemical precipitation. Photoanodes with varying rGO contents (1–4 wt.%) were systematically evaluated to assess their photovoltaic performance. The influence of rGO content on the composites was systematically investigated. Structural and morphological analysis by X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed enhanced crystallinity and superior particle dispersion with higher rGO loadings, while fourier transform infrared spectroscopy (FTIR) spectroscopy confirmed strong interfacial interactions. Electrochemically, cyclic voltammetry and stability tests showed that increased rGO significantly improved charge transport and activity. This was reflected in the photovoltaic performance: J–V characteristics under AM 1.5G illumination showed that the 4 wt.% rGO composite achieved the highest photocurrent density and capacitance, underscoring rGO’s role in optimizing conductivity and interfacial connectivity. The synergistic interplay among rGO, ZnO, Cu, and the PMMA matrix effectively suppresses charge recombination while accelerating electron transport, resulting in superior performance of the 4 wt.% rGO composite. This work establishes PMMA/rGO/ZnO/Cu composites as promising, cost-effective, and platinum-free photoanodes for high-efficiency solid-state DSSCs.