Triarylamine‐Substituted Imidazole‐ and Quinoxaline‐Fused Push–Pull Porphyrins for Dye‐Sensitized Solar Cells

Abstract

We have prepared a push-pull porphyrin with an electron-donating triarylamino group at the β,β'-edge through a fused imidazole group and an electron-withdrawing carboxyquinoxalino anchoring group at the opposite β,β'-edge (ZnPQI) and evaluated the effects of the push-pull structure of ZnPQI on optical, electrochemical, and photovoltaic properties. ZnPQI showed red-shifted Soret and Q bands relative to a reference porphyrin with only an electron-withdrawing group (ZnPQ), thus demonstrating the improved light-harvesting property of ZnPQI. The optical HOMO-LUMO gap was consistent with that estimated by DFT calculations. The ZnPQI-sensitized solar cell exhibited a relatively high power conversion efficiency (η) of 6.8 %, which is larger than that of the ZnPQ-sensitized solar cell (η=6.3 %) under optimized conditions. The short-circuit current and fill factor of the ZnPQI-sensitized solar cell are larger than those of the ZnPQ-sensitized solar cell, whereas the open circuit potential of the ZnPQI-sensitized cell is smaller than that of the ZnPQ-sensitized cell, leading to an overall improved cell performance of ZnPQI. Such fundamental information provides a new tool for the rational molecular design of highly efficient dye-sensitized solar cells based on push-pull porphyrins.

Weakly Conjugated Hybrid Zinc Porphyrin Sensitizers for Solid‐State Dye‐Sensitized Solar Cells

“…It is well known that the porphyrin sensitizers easily aggregate on semiconductor surface by π–π stacking interactions between porphyrin macrocycles, which mostly activates a de‐excitation channel through dipole–dipole interaction and leads to lower photovoltaic performance . Dye aggregation occurs during the adsorption process in the dye solution.…”

Strategic Synthetic Approaches to Porphyrin-Based Artificial Light-Harvesting Systems for Solar Energy Utilization

“…A push-pull porphyrin 77 was synthesized and studied with an electrondonating triarylamino group at the β,β′-edge through a fused imidazole group and an electron-withdrawing carboxyquinoxalino anchoring group at the opposite β,β ′-edge (Chart 22). 119 The 77-sensitized solar cell exhibited a relatively high PCE of 6.8%, which was larger than that of the 67-sensitized solar cell (6.3%) under optimized conditions. The short-circuit current and FF of the 77-sensitized solar cell were larger than those of the 67-sensitized solar cell, whereas the open circuit potential of the 77-sensitized cell was smaller than that of the 67-sensitized cell, leading overall to an improved cell performance of 77.…”

New Organic Donor–Acceptor–π–Acceptor Sensitizers for Efficient Dye‐Sensitized Solar Cells and Photocatalytic Hydrogen Evolution under Visible‐Light Irradiation

“…[25] They have already been widely utilized and show promising photovoltaic properties in bulk heterojunction solar cells [28][29][30] and DSSCs. [25,[31][32][33] Thus, the quinoxaline and pyrido- [3,4-b]pyrazine unit as a component for constructing novel D-A-p-A sensitizers are a very attractive approach due to their diverse structural modifications and intrinsic strong electronwithdrawing properties.…”