Pt‐Free Counter Electrode for Dye‐Sensitized Solar Cells with High Efficiency

Abstract

Dye-sensitized solar cells (DSSCs) have attracted widespread attention in recent years as potential cost-effective alternatives to silicon-based and thin-film solar cells. Within typical DSSCs, the counter electrode (CE) is vital to collect electrons from the external circuit and catalyze the I3- reduction in the electrolyte. Careful design of the CEs can improve the catalytic activity and chemical stability associated with the liquid redox electrolyte used in most cells. In this Progress Report, advances made by our groups in the development of CEs for DSSCs are reviewed, highlighting important contributions that promise low-cost, efficient, and robust DSSC systems. Specifically, we focus on the design of novel Pt-free CE catalytic materials, including design ideas, fabrication approaches, characterization techniques, first-principle density functional theory (DFT) calculations, ab-initio Car-Parrinello molecular dynamics (CPMD) simulations, and stability evaluations, that serve as practical alternatives to conventional noble metal Pt electrodes. We stress the merits and demerits of well-designed Pt-free CEs, such as carbon materials, conductive polymers, transition metal compounds (TMCs) and their corresponding hybrids. Also, the prospects and challenges of alternative Pt catalysts for their applications in new-type DSSCs and other catalytic fields are discussed.

A review on applications of Cu2ZnSnS4 as alternative counter electrodes in dye-sensitized solar cells

“…As mentioned earlier, CE mainly promotes the electron transfer from the external circuit back to the electrolyte at the surface of CE/electrolyte interface and accelerates the electrolyte reduction. 35 Thus, the main function of a CE is to speed up I 3 -reduction towards I -, which then regenerates the dye molecules. Therefore, CEs with the characteristics of both excellent electrocatalytic activity for I 3 -reduction and high electrical conductivity for electron transport are desirable.…”

“…Also, high conductivity for charge transport, good electrocatalytic activity for reducing the redox couple and excellent stability are the major contribution for choosing noble metal such as Pt, Au, Ag based CE. 35,36 However, as a noble metal, Pt becomes a trendsetter for applications as CE in DSSC that determines the main part of cost of the DSSC and limits its large scale applications. Superior catalytic activity, flexible electrochemical performance, good conductivity, high active area, cheaper and greener synthesis and fabrication techniques, effective performance is expected from CE alternative to Pt in DSSC.…”

Carbonaceous Dye‐Sensitized Solar Cell Photoelectrodes

“…This issue has led to some effort being focused on alternative photoelectrode materials, including those based on carbonaceous materials such as carbon particles, carbon nanotubes (CNTs) and, most recently, graphene. Therefore, review articles on carbon nanomaterials for the energy related applications are well documented 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28. It should be noted that since the production of this article, two other reviews of the use of graphene for DSSCs have been published 29, 30.…”

Recent Advances in Optimization of Photoanodes and Counter Electrodes of Dye-Sensitized Solar Cells

“…The unique energy band of GO along with its high specific surface area and electrical conductivity have been put to use in the fabrication of DSSCs, boosting the confidence in the potential of graphene and its various compounds in the area. In addition to the aforementioned carbonaceous materials, there has also been significant research employing conductive polymers and various nanohybrids in CEs which have been discussed by Yun et al 20 . Besides carbonaceous materials, certain other alternatives to Pt for fabrication of DSSC CEs have also been explored.…”