Linker effect of ethylenedioxythiophenes in platinum acetylide sensitizers with hybrid starburst donors for dye-sensitized solar cells

Abstract

The rational design and synthesis of sensitizers in dye-sensitized solar cells (DSSCs) by adjusting the structure of electron donor, π-bridge, or electron acceptor of D–π–A moieties is an effective mean for optimizing their photovoltaic performance. Herein, three novel D–π–M–π–A platinum acetylide sensitizers with different conjugated bridge or acceptor have been designed and synthesized. In particular, the concept of hybrid starburst donor was first introduced into the design of sensitizers in this study. It was found that the structure of the sensitizers influenced the photoelectric properties through affecting their absorption spectra, HOMO/LUMO orbits and electronic lifetime. The cell based on sensitizer H3, with aminophenyl acetylene and fluorene alkyne as the hybrid starburst donor, incorporating 3,4-ethylenedioxythiophene (EDOT) as π-bridge and cyanoacetic acid as acceptor, exhibited a 4.21% power-conversion efficiency under AM 1.5G sunlight.