Efficient Anthryl Dye Enhanced by an Additional Ethynyl Bridge for Dye-Sensitized Module with Large Active Area to Drive Indoor Appliances

For applications, having efficient modules with a large active area is paramount. In this work, two series of anthryl dyes were synthesized to study their fundamental properties and photovoltaic performance in dye-sensitized cells. After screening and optimization, a module sensitized with one of the dyes exhibits an overall efficiency of 13.48%, and it is capable of driving prototype application devices under indoor conditions. Chemical structures of the dyes are based on our previous champion anthryl dye (N,N-dioctyl-anilinyl-ethynyl-anthryl-ethynyl-benzothiodiazoyl-benzoic acid or AN-11, 11.94%). The first series consists of AN-11 as a reference and two other dyes bearing either an isophthalic acid (AN-11D) or a hydroxamic acid (AN-11H). For the second series of the dyes, their chemical structures differ from the first series counterparts in an additional ethynyl bridge between the benzothiadiazole acceptor and the anchoring group. As expected, the second series of the dyes give rise to red-shifted UV–visible absorptions, fluorescence emissions, and positively shifted reduction potentials. Significantly, the AN-21 module outperforms others with an overall efficiency of 13.48% under 1000 lx of T5 fluorescent light. Appearance-wise, the color of the AN-21 module is darker than that of the already very dark AN-11 module, owing to its broader and more intense incident photon-to-current conversion efficiency (IPCE) spectrum. Finally, we prepared three prototype appliances to showcase the AN-21 module’s ability of driving/powering real-life indoor applications.