A light-scattering co-adsorbent for performance improvement of dye-sensitized solar cells

A light-scattering cyanobiphenyl derivative 6-[(4'-cyano(1,1'-biphenyl)-4-yl)oxy]he-xanoic acid (CBHA) was designed, synthesized and applied as a co-adsorbent for dye-sensitized solar cells. The effect of CBHA on the light absorption and reflectance of dyed-TiO2 photoanodes was investigated in detailed. It revealed that a certain amount of CBHA adding to dye Z907 could obviously increase the light absorption of TiO2 photoanodes by decreasing the dye loading amount and possibility of aggregation. Meanwhile, light-scattering property of CBHA rendered their TiO2 photoanodes higher light-harvesting efficiency. In addition, electrochemical impedance spectroscopy results indicated that CBHA could restrain the interfacial electron recombination for longer life time. Thus, a performance improvement of ∼0.81% from 5.23% to 6.04% could be obtained by the resulting device employing CBHA. Moreover, the DSSCs with CBHA also display better stability than the referenced devices. This novel light-scattering co-absorbent offers us a feasible strategy to design multiple functional co-adsorbents for high performance dye-sensitized solar cells.