Highly Efficient Organic Sensitizers for Solid-State Dye-Sensitized Solar Cells

Organic sensitizers comprising of donor, electron-conducting, and anchoring groups are designed and developed for dye-sensitized solar cell applications. A solar cell employing 3-(5'-{4-[bis-(4-hexyloxy-phenyl)-amino]-phenyl}-[2,2']bithiophenyl-5-yl)-2-cyano-acrylic acid dye spiro-OMeTAD as a hole-transporting material exhibits a short circuit photocurrent density of 9.64 mA/cm(2), an open-circuit voltage of 798 mV, and a fill factor of 0.57, corresponding to an overall conversion efficiency of 4.4% at standard AM 1.5 sunlight. Photoinduced absorption spectroscopy probes an efficient hole-transfer from dyes to the spiro-OMeTAD.