posted on 2023-08-04, 17:34authored byQing Yun Li, Ravinder Kaur, William E. Meador, Juganta K. Roy, Jerzy Leszczynski, Jared H. Delcamp
Dye-sensitized solar cells (DSCs) can provide a clean
energy solution
to growing energy demands. In order to have devices of high performance,
sensitizers that are able to absorb in the near-infrared region (NIR)
are needed. Stronger electron donors are needed for intramolecular
charge-transfer sensitizers to access longer wavelength photons. Thus,
two novel organic dyes with a cross-conjugated dibenzosilin double
donor design are studied herein. The double donor delocalizes multiple
filled orbitals across both amine donors due to the fused design that
planarizes the donor as observed computationally, which improves intramolecular
charge-transfer strength. The dyes are studied via density functional
theory (DFT), optical spectroscopy, electrochemistry, and in DSC devices.
The studies indicate that the dye design can reduce recombination
losses, allowing for improved DSC device performances relative to
a single arylamine donor. The reduction in recombination losses is
attributed to the six alkyl chains that are incorporated into the
donor, which offer good surface protection.