A novel self-assembly based on double-layer zinc porphyrin sensitizers in supramolecular solar cell

Abstract

Two new self-assemblies based on zinc porphyrin dyes ZnPx-ZnPA (x = 1, 2) were synthesized and used for dye-sensitized solar cells. Capping layer dyes consist of zinc porphyrin (ZnP) as core unit and carbazole (P1), phenothiazine (P2) as electron-donating group. The dye ZnPA contains carboxylic group as an anchor porphyrin with upper dyes (denoted as ZnP1 and ZnP2) formed dyads by coordination bonds of Zn-to-ligand self-assembled devices. The assembly modes were also verified by transmission electron microscopy (TEM). The influence of the upper porphyrins on molecular structure as well as photovoltaic performance was investigated via photophysical and electrochemical studies and calculations. With addition of the phenothiazine unit, the ZnP2-ZnPA possesses better light-harvesting capability with a significantly red-shifted Q-band. The photoelectrochemical efficiencies for ZnP2-ZnPA are better than those of ZnP1-ZnPA ascribed to larger J_sc and V_oc.

Keywords:

• Dye-sensitized solar cells
• zinc porphyrin sensitizers
• self-assembly
• anchoring porphyrin

Acknowledgment

We are very grateful to Peng Wang (Changchun Institute of Applied Chemistry, Chinese Academy of Sciences) for supplying device fabrication and measurement of solar cells.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The National Natural Science Foundation of China (no. 21461023), Gansu Provincial Natural Science Foundation of China (no. 1606RJZA110) , Research on high-level talents of Qiannan Normal University for Nationalities (no. qnsyrc201703), Youth Science and Technology Talent Growth Project of Guizhou Provincial Education Department (No. QianJiaoHe KY Zi [2018]418) and Major projects of research and Innovation Fund of Qiannan Normal University for Nationalities (No. QNSY2018BS020) have supported this work.