Si and N Co-Doped Graphene Oxide as an Efficient Counter Electrode for Dye-Sensitized Solar Cells

Abstract

In this study, Si, N co-doped graphene oxide (GO) was synthesized using a simple and effective method. Structural and compositional analyses confirmed the successful integration of nitrogen and silicon into the GO lattice. XRD patterns revealed a change and expansion of the (001) peak, indicating reduced interlayer spacing and increased structural disorder. The Raman spectra showed a stronger D-band and shifts in higher-order peaks, suggesting greater defect density and altered carbon bonding. XPS results confirmed the presence of N–C and Si–O–C bonds, which confirmed efficient doping. J–V measurements in dye-sensitized solar cells (DSSCs) demonstrated that Si, N co-doped GO displays greatly improved conductivity and electrocatalytic activity compared to pristine and single-doped GO. As a counter electrode, its power conversion efficiency was 3.613%, outperforming other samples due to improved charge transport and active site density. These results emphasize the possibility of Si, N co-doped GO as a high-performance, metal-free material for advanced energy conversion applications.