An Intrinsically Conductive Phosphorus‐Doped Perovskite Oxide as a New Cathode for High‐Performance Dye‐Sensitized Solar Cells by Providing Internal Conducting Pathways

Abstract

State‐of‐the‐art dye‐sensitized solar cells (DSSCs) usually use the noble and scarce platinum (Pt) cathode, which strongly limits the practical applications of DSSCs. Accordingly, low‐cost, highly active, and stable alternatives to Pt are highly desired. Herein, an intrinsically conductive perovskite oxide is reported as a new cathode for DSSCs using a simple nonmetal element doping strategy. The phosphorus‐doped perovskite oxide (SrCo0.95P0.05O3−δ [SCP]) shows superior activity/durability for the triiodide (I3−) reduction reaction (IRR) and structural stability relative to the parent compound (SrCoO3−δ [SC]) due to the greatly enhanced electrical conductivity and the stabilization of the perovskite structure. The internal conducting pathways are demonstrated to be very important to obtain high IRR activity of the perovskite cathode, even when the cathode is incorporated with conductive multiwalled carbon nanotubes (MWCNTs). The DSSC with the N719 dye and SCP/MWCNTs cathode displays a superior power conversion efficiency (PCE) of 10.1% to those with Pt (8.11%) and SC/MWCNTs (6.80%) cathodes. In addition, the DSSC with the C101 dye and SCP/MWCNTs cathode shows an attractive PCE of 12.2% with an enhancement of 23%, as compared with the Pt cathode, suggesting that the SCP/MWCNTs composite can be one of the best substitutions to the Pt cathode, which can benefit the future industrialization of DSSCs.

Recent Advances in Cs2AgBiBr6-Based Halide Double Perovskites as Lead-Free and Inorganic Light Absorbers for Perovskite Solar Cells

“…The utilization of solar energy has been investigated widely in recent years due to the advantages of renewability and cleanability. , Photocatalysis and photovoltaics are two main routes for the utilization of solar energy. Water splitting to produce H 2 , pollutant degradation, and CO 2 reduction are main important applications of photocatalysis. − Moreover, photovoltaic devices such as dye-sensitized solar cells, quantum dot sensitized solar cells, organic polymer solar cells, and perovskite solar cells (PSCs), which can convert sunlight energy into electricity directly, have attracted increasing attention. − In particular, PSCs have been widely investigated due to their unique advantages of low cost and high efficiency. Hybrid organic–inorganic PSCs have achieved remarkable development since the first report in 2009 .…”

Tuning the A-Site Cation Deficiency of La0.8Sr0.2FeO3−δ Perovskite Oxides for High-Efficiency Triiodide Reduction Reaction in Dye-Sensitized Solar Cells

“…The superior IRR activity of LSF-0.98/MWCNTs may be attributed to two factors, namely, the oxygen vacancy amount and the valence states of B-site cations. ,, To in-depth investigate the origins of the high IRR activity of LSF-0.98/MWCNTs CE, XPS and oxygen nonstoichiometry titration were carried out as shown in Figure S5 and Table S2, respectively. The oxygen vacancy amounts of LSF, LSF-0.98, LSF-0.95, and LSF-0.9 samples were 0.05, 0.12, 0.21, and 0.32, respectively, while the calculated oxidation states of B-site Fe cations were 3.10, 3.02, 2.92, and 2.84, respectively, which demonstrated that the oxygen nonstoichiometry increased with the A-site cation deficiency increasing and the variation trend of oxidation state of iron was opposite.…”

“…Among various metal oxides-based cathode materials, perovskite oxides (ABO 3 ) have attracted intensive attention because of their compositional and structural flexibilities and fascinating properties. , Subtly controlling the oxidation states of metallic elements and the oxygen vacancy concentration in perovskite which can be achieved via rationally regulating the ratio of the metallic elements are able to maximize the IRR activity. , The ideal ABO 3 perovskite structure is known to contain an equal molar ratio of cations in both A and B locations. However, in reality, the lattice structure of perovskite can still remain stable even when the ratio of A/B-site cations deviate from the unit .…”

Metal Chalcogenides (MxEy; E = S, Se, and Te) as Counter Electrodes for Dye–Sensitized Solar Cells: An Overview and Guidelines

“…This work inspired many other researchers to explore perovskite oxide/carbon composites as potential CEs for DSSCs. [204,[206][207][208][209] However, very few works report the use of perovskite oxide/metal chalcogenide composites as CEs for DSSCs despite their great performance. [204] Oh et al [207] reported a double perovskite oxide/metal selenide-graphene composite (graphene-La 2 CuNiO 6 -ZnSe "G-LCN-ZS") as CEs for DSSCs.…”