Ion coordinating sensitizer for high efficiency mesoscopic dye-sensitized solar cells: influence of lithium ions on the photovoltaic performance of liquid and solid-state cells

Nano Lett. 2006 Apr;6(4):769-73. doi: 10.1021/nl060075m.

Abstract

A Li+ coordinating sensitizer, NaRu(4-carboxylic acid-4'-carboxylate)(4,4'-bis[(triethylene glycol methyl ether) methyl ether]-2,2'-bipyridine)(NCS)2 (coded as K51), has been synthesized, and the effect of Li+ coordination on its performance in mesoscopic titanium dioxide dye-sensitized solar cells has been investigated. Fourier transform infrared spectra suggest that Li+ coordinates to the triethylene oxide methyl ether side chains on the dye molecules. With the addition of Li+ to a nonvolatile liquid electrolyte, we observe a significant increase in the photocurrent density, with only a small decrease in the open-circuit voltage, contrary to a non ion coordinating dye which displays a large drop in potential with the addition of Li+. For a solar cell incorporating an organic hole-transporter, we find the potential rises with increasing the Li+ concentration in the hole-transporter matrix. For the liquid electrolyte and solid-state cells, we obtain power conversion efficiencies of 7.8% and 3.8%, respectively, under simulated sunlight.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Coloring Agents
  • Electric Power Supplies*
  • Electrochemistry / instrumentation*
  • Equipment Design
  • Equipment Failure Analysis
  • Ions
  • Light
  • Lithium / chemistry*
  • Materials Testing
  • Nanostructures / chemistry*
  • Nanostructures / radiation effects
  • Nanotechnology / instrumentation*
  • Phase Transition
  • Photochemistry / instrumentation*
  • Titanium / chemistry*
  • Titanium / radiation effects

Substances

  • Coloring Agents
  • Ions
  • titanium dioxide
  • Lithium
  • Titanium