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Introduction

The Grätzel Cell, or dye-sensitized solar cell is an solar cell that uses titanium dioxide as its semiconductor, a dye as the light absorber, and an iodine relay as an electron shuttle. It functions by absorbing photons and transferring excited electrons through the TIO2 to perform work, like a silicon solar cell. The cell is regenerated through the anode with I-/I-3.

Hypothesis

If we use a blueberry juice-coated electrode in combination with a soot-covered electrode, then our output will be higher than the blackberry cells because the blueberry dye appears to absorb more wavelengths.

Procedures

  • Coat FTO glass electrodes in a 50 micron layer of Titanium dioxide
  • Soak TIO2 panels with concentrated blackberry or blueberry juice
  • Coat the other FTO electrode with either soot or graphite
  • Deposite l-/I3- solution on the TiO2
  • Clamp the two panels together.
  • Place under a light source and measure voltage and current

Abstract

Alternative energy options, especially solar power, are a big part of today’s energy economy. Over the course of three weeks we built and tested several different solar cells with differing dyes and electrode materials to determine which combination would have the highest performance. We tested 3 cells of each combination of blueberry or blackberry dye and soot or graphite catalysts. Of the 12 cells, those with blueberry dye and a soot backing had the highest voltage and current.

Results and Analysis

The blueberry cells had an average voltage of 341 ± 72 mVOC and an average current of 41 ± 22 µASC. There was an outlier with a voltage of 200 mVOC and a current of 5 µASC. The blackberry cells had an average voltage of 258.2 ± 45 mVOC and an average current of 27 ± 9 µASC.

Conclusion

The blueberry-soot results confirm our initial hypothesis that the blueberry-soot cells would perform the best. Our testing was not perfect, but the most that could be accomplished in a short time. The results add to the knowledge about the potential of non-silicon based solar cells.

Materials

  • Titanium Dioxide
  • FTO conductive glass
  • multimeter
  • ethanol
  • number 2 pencil
  • candle and lighter
  • blueberries
  • blackberries
  • 0.01M Nitric Acid

Problem

Which berry-based dye and carbon catalytic coating combination will result in the best current and voltage output from the solar cells when they are exposed to a black body radiator?

By Mohini Schaefers, Ben Goldberg, Loki Dunbar, and Inara Jensen

Discussion

The most efficient solar cells were formed from a darker juice and a more effective counter electrode. The blueberry did better due to its red shifted absorption; there are more available red photons than blue. Solar cell US4 was an outlier because we had to reconstruct the cell after it was already clamped together.

Acknowledgements: We thank Dr. Brian Leigh, Dr. Robert Pomeroy, and Dr. Michael Tauber for their teachings and the knowledge they shared, Jonathan Ty for his instruction and moral support, and Anton Samoylov for his insight and

Dye-Sensitized Solar Cells