Stability assessment of alternative platinum free counter electrodes for dye-sensitized solar cells

Abstract

Platinum (Pt)-free counter electrodes (CEs) are economical alternative components of dye-sensitized solar cells (DSSCs) that have attracted much interest and become the focus of research, with an increasingly large number of scientific papers published in the last two decades. The development of these CE materials was driven mainly by desires to overcome the disadvantages of Pt, as follows: high cost, scarcity, corrosion by the I3\u7f/I\u7f redox couple electrolyte, and mismatch or non-effectivity in the I-free redox couple electrolyte. Although much more is now known about the principal physicochemical processes that occur during CE operation of the DSSC, the stability issues associated with CEs have not been matched by the exponential increase in CE research effort. This raises questions regarding the stability of the CEs whether the present research is sufficiently addressing the stability issues that limit DSSC performance. This review attempts to identify some of the key techniques that evaluate CE stability in DSSCs through a selective presentation of recent research highlights. Classical approaches could effectively assess the probability of using alternative Pt-free CE materials for commercial application, which offer strategies to overcome the current stability stalemate

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

“…5(b). 48,49,65 In contrast to common oxides, CZTS, as a direct band gap semiconductor, has the band gap energy of ∼1.4-1.5 eV and is close to the optimal band gap energy of 1.45 eV. In addition, CZTS has a high absorption coefficient >10 4 cm -1 along with intrinsic p-type conductivity of CZTS also makes it a suitable CE due to the fast transfer of photo-generated holes and further efficiency.…”

“…They are carbon, metal sulfide and oxide based, transition metal nitrides and carbides, polymers and carbon-polymer composites and other composites. [46][47][48][49][50][51][52][53][54][55] Remarkably, all the alternative CEs are established as a potential replacement to Pt in due course of its synthesis strategy, morphology-size tunable property, fabrication policy etc. The reported alternative CEs mainly concentrating on different synthesis processes which can lead to industrial scale manufacturing.…”

Use of Transition Metal Compounds in Solar and Biomass Energy

“…In a typical DSSC, the Pt electrode is the preferred CE material, owing to its superior catalytic activity and electrical conductivity. However, the Pt electrode faces some serious challenges, as described in previous literatures [3][4][5]. Therefore, it is crucial to develop alternative Ptfree CE materials for high-performance DSSCs.…”

“…Thus far, Pt metal, metal and alloys, conducting polymers, carbon materials, TMCs, and hybrids as alternative Pt-free CEs have been developed and tested in DSSCs, which have been the focus of several review papers [3,[6][7]. Among these alternative Pt-free CEs, TMCs have attracted significant attention, due to their distinctive structure and unique properties.…”

Cobalt-Based Electrolytes for Dye-Sensitized Solar Cells: Recent Advances towards Stable Devices

“…In these devices, the electrolyte plays a central role in determining both efficiency and durability [7,8]. Indeed, the redox couple dissolved in the organic solvent has the aim of capturing electrons that reach the counter-electrode [9][10][11] and to regenerate the oxidized dye acting as a sensitizer [12][13][14].…”