研究目的
Investigating the binding of two electrolyte additives, 4-tert-butylpyridine (4-TBP) and 2,2’-bipyridine (bipy), to the surface of TiO2 photo-anode and their influence on dye-sensitized solar cells’ performance.
研究成果
We demonstrated an efficient way to chemically graft 4-tert-butylpyridine (4-TBP) and 2,2’-bipyridine (bipy) on the surface of TiO2. The binding between the bipy and the TiO2 surface mainly occurred via a Ti-O-N linkage, whereas the binding between the 4-TBP and the TiO2 surface was via both Ti-O-N and Ti-N bonds. DSC cells prepared with N-additive grafted TiO2 photo-anodes had lower short current and light to electricity efficiencies than non-grafted cells. The open circuit voltage (Voc) was, however, increased 110 mV for 4-TBP grafted cells with 0.5 M 4-TBP in the electrolyte. One third of the overall increase in Voc was estimated to be due to the adsorption of the 4-TBP to the TiO2 surface. The remaining Voc increase was attributed to effects of 4-TBP on the electrolyte. We have proposed that the electrolyte effect is due to a reduction of the free I3- concentration by complexation with 4-TBP and reduction of the back electron transfer loss reaction from the conduction band to I3-.
研究不足
The technical and application constraints of the experiments, as well as potential areas for optimization.