A Quasi-Solid State DSSC with 10.1% Efficiency through Molecular Design of the Charge-Separation and -Transport

Abstract

Organic-based solar cells potentially offer a photovoltaic module with low production costs and low hazard risk of the components. We report organic dye-sensitized solar cells, fabricated with molecular designed indoline dyes in conjunction with highly reactive but robust nitroxide radical molecules as redox mediator in a quasi-solid gel form of the electrolyte. The cells achieve conversion efficiencies of 10.1% at 1 sun, and maintain the output performance even under interior lighting. The indoline dyes, customized by introducing long alkyl chains, specifically interact with the radical mediator to suppress a charge-recombination process at the dye interface. The radical mediator also facilitates the charge-transport with remarkably high electron self-exchange rate even in the quasi-solid state electrolyte to lead to a high fill factor.

Dye-Sensitized Solar Cells: Fundamentals and Current Status

“…They obtained an appreciable efficacy of 10.1% at 1 sun. To suppress a charge-recombination process at the dye interface, they introduced long alkyl chains, which specifically interact with the radical mediator [ 229 ]. Recently in 2017, Irgashev et al synthesized a novel push-pull thieno[2,3-b]indole-based metal-free dyes and investigated their application in DSSCs [ 230 ].…”

Performance of the dye-sensitized quasi-solid state solar cell with combined anthocyanin-ruthenium photosensitizer

“…The better stability of the quasi-solid state electrolyte is also the reason for researchers to fabricate solar cells with more stability. 31,[62][63][64][65][66][67] In this case, by comparing two electrolytes with a similar I À composition, then considering the dye regeneration by I À with the mechanism given eqn 4, we can analyze that the quasi-solid state electrolyte presented better dye regeneration due to the 0.012 V lower oxidation potential compared to the liquid electrolyte, resulting in a sharper peak current I pc by about 2.46 mA than that of the liquid electrolyte. As a result, all the dyes have higher open potential voltages by about 0.056, 0.006, and 0.004 V for anthocyanin, combined anthocyanin-N719, and N719, respectively, as tabulated in Table 6.…”

The researcher's guide to solid-state dye-sensitized solar cells

“…Triphenylamine (TPA) based dyes are the most successful organic dyes due to their structural versatility and high absorption coefficients. 107,[182][183][184] The implementation of the TPA dyes started with the work by Hagfeldt and coworkers with the D35 dye and its bulky o,p-dibutoxyphenyl groups. The D35-based devices showed a promising PCE of 4.5%, due to improved electron lifetime in the device.…”