Much attention has recently been devoted to the design and synthesis of vis–NIR-absorbing chromophores that are suitable for use as photosensitizers in dye-sensitized solar cells (DSSCs).[1] Amongst the different classes of chromophores that have been proposed for this application so far,[2] squaraine dyes have been considered because of their strong intrinsic absorption in the 600–800 nm region and their high thermal and chemical stabilities.[3] Squaraines are the products of condensations of electron-rich molecules with squaric acid.[4] Their structure can be either symmetric or nonsymmetric. This (non)- symmetry depends on the synthetic route employed and has enabled the preparation of a wide variety of functional structures, which have thus far been exploited in, for example, photoconductive materials, light emitting field-effect transistors, fluorescence patterning, and optical limiting.[5] However, both symmetric and nonsymmetric squaraines possess an important drawback: their absorption, although very efficient (with extinction coefficients often exceeding 300 000 Lmol1 cm1 ), is limited to one relatively narrow band located in the aforementioned 600–800 nm region. This weakness is partially compensated by a sizeable broadening of the absorption band in the solid state.
Panchromatic cross-substituted squaraines for dye-sensitized solar cell applications
De Angelis, Filippo
;
2009
Abstract
Much attention has recently been devoted to the design and synthesis of vis–NIR-absorbing chromophores that are suitable for use as photosensitizers in dye-sensitized solar cells (DSSCs).[1] Amongst the different classes of chromophores that have been proposed for this application so far,[2] squaraine dyes have been considered because of their strong intrinsic absorption in the 600–800 nm region and their high thermal and chemical stabilities.[3] Squaraines are the products of condensations of electron-rich molecules with squaric acid.[4] Their structure can be either symmetric or nonsymmetric. This (non)- symmetry depends on the synthetic route employed and has enabled the preparation of a wide variety of functional structures, which have thus far been exploited in, for example, photoconductive materials, light emitting field-effect transistors, fluorescence patterning, and optical limiting.[5] However, both symmetric and nonsymmetric squaraines possess an important drawback: their absorption, although very efficient (with extinction coefficients often exceeding 300 000 Lmol1 cm1 ), is limited to one relatively narrow band located in the aforementioned 600–800 nm region. This weakness is partially compensated by a sizeable broadening of the absorption band in the solid state.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
