Catalysts In Dye-sensitized Solar Cells Research Articles

Recent Progress of Counter Electrode Catalysts in Dye-Sensitized Solar Cells

To realize long-term developments and practical application of the dye-sensitized solar cells (DSCs) requires a robust increase of the power conversion efficiency (PCE) and a significant decrease of the production cost. Fortunately, a new record PCE value of 12.3% was achieved by using cobalt-based redox couples combined with organic dye. Evidently, dye design is the key path to improve the PCE, while developing low cost counter electrode (CE) catalysts is one of the promising paths to reduce the production cost of DSCs by replacing the expensive Pt CE. In this article, we review the recent progress of CE catalysts involving Pt, carbon materials, inorganic materials, multiple compounds, polymers, and composites. We discuss the advantages and disadvantages of each catalyst and put forward ideas for designing new CE catalysts in future research for DSCs and other application fields.

Titanium Carbide and Titanium Nitride-Based Nanocomposites as Efficient Catalysts for the Co2+/Co3+ Redox Couple in Dye-Sensitized Solar Cells

Two different kinds of nanocomposites were developed by electrochemical deposition of poly(3,4-ethylenedioxythiophene) (PEDOT) into porous hard template films of TiC or TiN nanoparticles, in order to evaluate their use as alternative catalysts in dye-sensitized solar cells (DSSC) utilizing a Co2+/Co3+ polypyridyl redox mediator. Cyclic voltammograms indicate that both types of nanocomposite show comparable catalytic activity to platinum-coated electrodes. However, electrochemical impedance spectroscopy (EIS) reveals that electron transfer resistances are significantly reduced with the porous nanocomposite electrodes (<1 Ω), to about an order of magnitude lower than those observed for the Pt coated electrode. As a result, DSSCs with the composite counter electrodes achieved equivalent or higher photovoltaic conversion efficiencies compared to cells with pristine PEDOT or Pt coated electrodes. In particular, the highest efficiency (8.26%) was achieved with a DSSC using a TiN-PEDOT counter electrode.

NiO as an Efficient Counter Electrode Catalyst for Dye-Sensitized Solar Cells

NiO is an important heterogeneous catalyst employed in chemical processes. However, it is a new topic to explore NiO as a counter electrode catalyst for dye-sensitized solar cells (DSSCs). In this paper, NiO with poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) was demonstrated an efficient DSSC counter electrode with a maximum power conversion efficiency of 7.58 %. Furthermore, electrochemical impedance spectroscopy and cyclic voltammetry measurements revealed that the excellent photovoltaic performance is due to the combination between the high catalytic activity of NiO and the superior electrical conductivity of PEDOT:PSS. The optimum weight ratio of NiO to PEDOT:PSS is 48.

Metal Oxide/Carbide/Carbon Nanocomposites: In Situ Synthesis, Characterization, Calculation, and their Application as an Efficient Counter Electrode Catalyst for Dye‐Sensitized Solar Cells

This paper describes the metal oxide/carbide/carbon nanocomposites and in situ synthesis, characterization, calcn. and their application as efficient counter electrode catalyst for dye-sensitized solar cells. The poor adhesion between carbon-based materials and fluorine-doped tin oxide (FTO) substrate limits the application of counter electrode (CEs) in dye-sensitized solar cells (DSC).

Functionalized graphene/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate as counter electrode catalyst for dye-sensitized solar cells

A (grapheme/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) graphene/PEDOT:PSS composite film was electrodeposited on fluorine-doped tin oxide conductive substrate by one-step electrochemical polymerization method. The low-cost and platinum-free film was used as counter electrode in (dye-sensitized solar cell) DSSC. The cyclic voltammetry, electrochemical impedance spectroscopy and Tafel measurements indicate that the graphene/PEDOT:PSS composite film has low charge-transfer resistance on the electrolyte/electrode interface and high catalytic activity for the reduction of triiodide to iodide and. As a result, the DSSC based on the graphene/PEDOT:PSS counter electrode showed high power conversion efficiency of 7.86% under a simulated sunlight illumination of 100 mW cm−2 (AM 1.5), which is comparable with the performance of the DSSC based on Pt counter electrode (7.31%).

Pt‐like Behavior of High‐Performance Counter Electrodes Prepared from Binary Tantalum Compounds Showing High Electrocatalytic Activity for Dye‐Sensitized Solar Cells

Ta-based compounds show Pt-like behavior: Binary tantalum compounds as counter electrodes (CEs) in dye-sensitized solar cells (DSCs) demonstrate Pt-like electrocatalytic activity and competitive photovoltaic performance, matching the performance of DSCs with Pt CEs. The first-principle density functional theory (DFT) calculations provide a strategy for understanding the relationship between the electronic structure and the catalytic activity of CE catalysts in DSCs.

Dye-sensitized solar cells based on hydroquinone/benzoquinone as bio-inspired redox couple with different counter electrodes

In the present study, tetramethylammonium hydroquinone (HQ)/benzoquinone (BQ) were developed for use as a redox couple, with poly(3,4-ethylenedioxythiophene) (PEDOT) and multiwalled carbon nanotubes (MWNT) being proposed for use as counter electrode (CE) catalysts in dye-sensitized solar cells (DSSCs). Both metal-complex N719 and metal-free organic dye CM309 were employed to fabricate devices. For the devices sensitized by N719, when using PEDOT and MWNT CEs, power conversion efficiencies (PCE) of 5.2 and 4.9% were obtained, respectively, which were much higher than that of the device using the traditional Pt CE (4.7%) when HQ/BQ electrolyte was employed. However, with the HQ/BQ redox shuttle, the efficiency of the devices sensitized by N719 is much lower than that of the devices when the traditional I(-)/I3(-) based electrolyte and Pt CE were employed (7.9%). While for the CM309 sensitized solar cells, when the HQ/BQ redox shuttle was employed, PEDOT and MWNT performed much better than Pt, the DSSC using the PEDOT CE showed an efficiency of 6.2%, which was close to that of the DSSC using the traditional I(-)/I3(-) electrolyte and Pt CE (6.3%).

Pulse-reverse electrodeposition of transparent nickel phosphide film with porous nanospheres as a cost-effective counter electrode for dye-sensitized solar cells

A Ni2P nanolayer with porous nanospheres was directly coated on fluorine-doped tin oxide glass by pulse-reverse deposition as a low-cost counter electrode catalyst for dye-sensitized solar cells, and the photoelectron conversion efficiency of the cell was increased to 7.32% by using a porous nanosphere catalyst due to the significantly improved ion transport.

High-performance phosphide/carbon counter electrode for both iodide and organic redox couples in dye-sensitized solar cells

In the present study, molybdenum phosphide (MoP), nickel phosphide (Ni5P4), and carbon-supported Ni5P4 (Ni5P4/C) were proposed for use as counter electrode (CE) catalysts in dye-sensitized solar cells (DSCs) for the regeneration of both the conventional I3−/I− redox couple and a new organic T2/T− redox couple. For the I3−/I− redox couple, the DSCs using MoP and Ni5P4 CE yielded a power conversion efficiency (PCE) of 4.92 and 5.71%, and the DSC using Ni5P4/C showed a high PCE of 7.54%, which was close to that of the DSC using Pt CE (7.76%). For the T2/T− redox couple, Ni5P4/C performed much better than Pt and the DSC using Ni5P4/C CE showed a PCE of 4.75%, much higher than the photovoltaic performance of the DSC using Pt CE (3.38%).