An investigation into the origin of variations in photovoltaic performance using D-D-π-A and D- A-π-A triphenylimidazole dyes with a copper electrolyte

摘要

The potential of using non-planar triphenylimidazole-donor-based dyes in dye-sensitized solar cells was explored synthesizing two novel dyes, LG-P1 and LG-P3,withD-D-π-A and D-A-π-A architectures, respectively. Anthracene and benzothiadiazole were used as the auxiliary donor and auxiliary acceptor units, respectively, in these newly designed sensitizers. The dyes were custom-designed to have a more positive ground state potential to make them compatible with a new-generation alternative copper electrolyte, [Cu(dmp)2] 1+/2+. We investigated various factors contributing to the variations in the photovoltaic performance upon the use of triphenylimidazole dyes with different auxiliary donor and acceptor units with [Cu(dmp)2] 1+/2+ electrolyte. Based on our observations, the triphenylimidazole dye having D-A-π-A architecture with benzothiadiazole as the auxiliary acceptor unit delivered better photovoltaic performance than the dye with anthracene as an auxiliary donor with D-D-π-A architecture. Electrical and optical perturbation methods were used to systematically probe the charge transfer and transport behaviours at the interfaces when employing these sensitizers.