Three Keggin-Type Transition Metal-Substituted Polyoxometalates as Pure Inorganic Photosensitizers for p-Type Dye-Sensitized Solar Cells

Abstract

In light of the serious challenge of severe global energy shortages, p-type dye-sensitized solar cells (p-DSSCs) have attracted increasing levels of interest. The potential of three Keggin-type transition metal-substituted polyoxometalates, TBA₈ Na₂ [SiW₉ O₃₇ {Co(H₂ O)₃ }]⋅ 11 H₂ O (SiW₉ Co₃ ), TBA₄ [(SiO₄ )W₁₀ Mn^III₂ O₃₆ H₆ ]⋅1.5 CH₃ CN⋅ 2 H₂ O (SiW₁₀ Mn^III₂ ), and TBA_3.5 H_5.5 [(SiO₄ )W₁₀ Mn^III/IV₂ O₃₆ ]⋅ 10 H₂ O⋅0.5 CH₃ CN (SiW₁₀ Mn^III/IV₂ ) has been explored as pure inorganic dye photosensitizers for p-DSSCs (TBA=(n-C₄ H₉ )₄ N⁺ ). The three dyes show overall conversion efficiencies of 0.038, 0.029, and 0.027 %, respectively, all of which are higher than that of coumarin 343 (0.017 %). These polyoxometalates are the first three pure inorganic dyes reported for use with p-DSSCs and therefore demonstrate a new strategy for designing efficient dyes, especially pure inorganic dyes. Moreover, they broaden the range of applications for polyoxometalates.

Keywords: dye-sensitized solar cells; energy conversion; photosensitizers; polyoxometalates.