Improvement of the performance of dye-sensitized solar cells employing NickelPalladium alloy-reduced graphene oxide counter electrode: Influence of palladium content

Abstract

In this work, NickelPalladium-reduced graphene oxide (NiPd-rGO) films have been prepared via liquid phase deposition technique and used as free-platinum (Pt) counter electrode for dye-sensitized solar cell (DSSC). The effect of Pd content in term of various Ni:Pd ratios on the properties such as structure, optical transmission, surface morphology and elemental compositions have been studied. The morphology of NiPd-rGO sample is in the form of crumpled vertical folds in layers and white strips. The influence of Pd content on photovoltaic parameters of the device has also been investigated. The performance parameters were significantly influenced by the Pd content. The device using NiPd-rGO counter electrode prepared at Ni:Pd ratio of 20:2 demonstrated the highest PCE of 3.09%. This is due to the device owns the highest charge recombination resistance (Rrec) and shortest carrier transport time (τ). The efficiency has been improved at the optimum content of Pd. The finding from this work implies that NiPd-rGO is able to substitute Pt as counter electrode in DSSC due to its efficiency is comparable to that of the device employing Pt counter electrode.