Nickel oxide and carbon allotropes-based nanohybrids show enhanced efficiency of p-type dye-sensitized solar cells

In this study, we investigated the optimal carbon allotropes to enhance the performance of p-type dye-sensitized solar cells (DSSCs) with NiO. Various allotropes of carbon, including multi-walled carbon nanotubes (MWCNT), reduced graphene oxide (RGO), graphene quantum dots (GQD), and fullerene (C60), were examined for their distinct structural and electrochemical properties. When incorporated with NiO, these carbon allotropes displayed a power conversion efficiency (PCE) trend of (NiO@GQD) NG < (NiO@fullerene) NF < (NiO@RGO) NR < (NiO@f-MWCNT) NM, with corresponding PCE values of 0.55%, 0.60%, 0.72%, and 0.80%. The quantum efficiency (QE) values of NG, NR, NF, and NM were found to be approximately 62%, 65%, 70%, and 80%, respectively. Among the four NiO-based nanohybrids, the NM-based device exhibited the highest PCE of 0.80%, with a short-circuit current density (Jsc) of 2.53 mA cm⁻², an open-circuit voltage (Voc) of 0.56 V, and a fill factor (FF) of 56.46%. This superior performance is attributed to the enhanced dye adsorption and rapid charge transfer properties facilitated by the NM nanohybrid.