QPorQPcQdaP · The Development of Quinoidal Porphyrins, Quinoidal Phthalocyanines, and Quinoidal Diazaporphyrins for Dye-Sensitized Solar Cells: Into the Red

The development of novel materials is crucial to the improvement of solar cells. State-of-the-art dye-sensitized solar cells utilize “push-pull” porphyrin dyes (coded YD2-oC8) and have reported efficiencies up to 12.3%. However, YD2-oC8 and structurally similar dyes display limited to no absorption in the far red and near infrared regions of the solar spectrum. This region is where photon flux is at a maximum and improved absorption in this area should result in improved device efficiencies. We propose optimizing the under-studied quinoidal porphyrins and synthesizing novel quinoidal phthalocyanines and quinoidal diazaporphyrins to address the long wavelength absorption deficiencies of state-of-the-art porphyrin dyes. Quinoidal porphyrins have pronounced far-red/near infrared absorption and can be tuned similar to bona fide porphyrins. Pristine phthalocyanines already have adequate long wavelength absorption, but devices made from these dyes have low efficiencies as a result of strong dye aggregation. Quinoidal phthalocyanines should be non-planar similar to other large quinoidal species (exTTFs, porphyrins, etc.). This trait is proposed to lead to significantly reduced aggregation, improving the photophysical attributes, as well as the processability of phthalocyanines. The synthesis of the proposed dyes will help elucidate the importance of long wavelength absorption in dye-sensitized solar cells, shed light on the applicability of quinoidal porphyrinoid dyes and, in the long term, lead to higher efficiency solar cells. The applicant has extensive experience with the quinoidal porphyrins and is uniquely skilled to carry out this project.