Triazoloisoquinoline-based/ruthenium-hybrid sensitizer for efficient dye-sensitized solar cells

Triazoloisoquinoline-based organic dyestuffs were synthesized and used in the fabrication of dye-sensitized solar cells (DSSCs). After cosensitization with ruthenium complex, the triazoloisoquinoline-based organic dyestuffs overcame the deficiency of ruthenium dyestuff absorption in the blue part of the visible spectrum. This method also fills the blanks of ruthenium dyestuff sensitized TiO₂ film and forms a compact insulating molecular layer due to the nature of small molecular organic dyestuffs. The incident photon-to-electron conversion efficiency of N719 at shorter wavelength regions is 49%. After addition of a triazoloisoquinoline-based dyestuff for co-sensitization, the IPCE at 350-500 nm increased significantly. This can be attributed to the increased photocurrent of the cells, which improves the dye-sensitized photoelectric conversion efficiency from 6.23% to 7.84%, and the overall conversion efficiency increased by about 26%. As a consequence, this low molecular weight organic dyestuff is a promising candidate as coadsorbent and cosensitizer for highly efficient dye-sensitized solar cells.