A Review on Chalcogenide-Based Materials for Counter Electrode Applications in Dye-Sensitized Solar Cells: Sulfides, Selenides, and Tellurides

Abstract

Dye-sensitized solar cells (DSSCs) have drawn attention in recent years for their cost-efficient, green, and convenient means of harnessing solar power. The function of DSSCs is designed around the counter electrode (CE), which is traditionally composed of platinum (Pt) for its good catalytic activity and good electric conductivity. However, Pt is expensive and in short quantity, and extensive studies have gone in search of substitute materials. Among them, materials in the system of chalcogenides, such as sulfides, selenides, and tellurides, have drawn considerable attention as potential candidates. These materials have various unique advantages, such as their capability to modulate their electronic property, good catalytic activity, and good resistance to chemicals, and therefore have good potential for optimizing function of DSSCs. This review presents an in-depth overview of where the situation stands in chalcogenide-based CEs, critically evaluating their synthetic routes, electrocatalytic activity, and stability. We compare and contrast various synthetic routes, such as hydrothermal, solvothermal, electrodeposition, chemical vapor deposition, atomic layer deposition, and solution-based synthesis, employed to alter the nanostructure and topography of such materials. Sulfide- and selenide-based materials have displayed competing power conversion efficiencies and favorable charge transfer behavior, but tellurides have potential through their exceptionally good electric conductivity. Despite such breakthroughs, limitations such as corrosion by the electrolyte, phase instability, and scalability of the routes of fabrication persist and serious bottlenecks persist. This review suggests possible strategies such as doping, composite formation, and formation of the protective layer to overcome such limitations and to ensure cost-efficient, high-performance DSSCs.

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Structural illustration of the conventional DSSCs.

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PCE, J _sc, V _oc, and FF as a function of time for ZCS-based CE DSSCs. Reprinted with permission from ref (CC-BY). Copyright 2023 The Authors, Published by MDPI.

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Illustration of Co₉Se₈–CuSe₂–WSe₂ hollow balls. Reprinted with permission from ref . Copyright 2024 ACS.

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Normalized efficiency for 0–1000 h of DSSCs fabricated with Pt and illustration of Co₉Se₈–CuSe₂–WSe₂ + MWCNTs. Reprinted with permission from ref . Copyright 2024 ACS.

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DSSCs fabricated with TeMC as a transparent CE for bifacial DSSCs. Reprinted with permission from ref (CC-BY). Copyright 2020 The Authors, Published by MDPI.

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Sequence EIS measurements of DSSCs fabricated with (a) Pt CE and (b) TeMC CE with inset figure of comparison of R _ct for Pt and TeMC CEs with 10 EIS repeated measurements. Reprinted with permission from ref (CC-BY). Copyright 2020 The Authors, Published by MDPI.

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Schematic diagram of the conventional hydrothermal synthesis.

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SEM images of (a) WS₂, (b) MoS₂, and (c) MoS₂/WS₂ nanosheets. Reprinted with permission from ref (CC-BY-NC). Copyright 2017 RSC. Copyright 2017 The Authors, Published by RSC.

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Conventional schematic of electrodeposition. Reprinted with permission from ref (CC-BY). Copyright 2020 The Authors, Published by MDPI.

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Synthesis of MoS₂ flake through CVD using different deposit conditions: (a) sulfur and molybdenum powders deposited on substrates, (b) sulfur powders deposited on a molybdenum thin layer, (c) sulfur powders deposited on liquid molybdenum precursors, (d) sulfur and molybdenum powders and drop-casted promoters, and (e) sulfur and molybdenum gases deposited on substrates. Reprinted with permission from ref (CC-BY). Copyright 2021 The Authors, Published by MDPI.

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TEM images of MoS₂ films with SAED patterns deposited at (a) 750 and (b) 850 °C. Reprinted with permission from ref (CC-BY). Copyright 2023 The Authors, Published by MDPI.

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Smooth topology of Al₂O₃ films deposited at 80 °C (T80), 100 °C (T100), 150 °C (T150), and 250 °C (T250). Reprinted with permission from ref (CC-BY). Copyright 2022 The Authors, Published by Springer.

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MoS₂ monolayers deposited via ALD. Adopted with permission from ref (CC-BY). Copyright 2021 The Authors, Published by AIP.

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Chalcogenide films of S/Se/S and Se/S/Se deposited via a spin coating. Reprinted with permission from ref (CC-BY). Copyright 2023 The Authors, Published by Springer.

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Illustration of the conventional spin-coating process.

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Schematic sulfurization for Sb₂S₃ fabrication. Reprinted with permission from ref (CC-BY). Copyright 2024 The Authors, Published by MDPI.

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Sulfurization of MoS₂ from MoO_3–x . Adopted with permission from ref (CC-BY). Copyright 2025 The Authors, Published by ACS.

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Selenization of CoMoO₄ nanosheets using Se powder to form CoSe₂/MoSe₂. Reprinted with permission from ref (CC-BY). Copyright 2020 The Authors, Published by Frontiers.

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R _ct analysis of CoMoO₄, CoSe₂/MoSe₂, CoSe₂, and MoSe₂. Reprinted with permission from ref (CC-BY). Copyright 2020 The Authors, Published by Frontiers.