Study On Effects Of Poly(3-hexylthiophene) And Dye On The Performance Of Solid-state Dye-sensitized Solar Cells

Dye-sensitized solar cells are considered as an emerging technology in order toreplace conventional solar cells. However, liquid electrolytes have a durability problemdue to the corrosion of metal contacts. In comparison to the liquid electrolytes, theefficiencies of solid-state dye-sensitized solar cells are inferior, which are around only30%of the efficiencies obtained with the liquid electrolytes. In view of this, we usedpoly(3-hexylthiophene)(P3HT) as a hole transport material，focusing on the pore-filling,light harvesting, recombination problems of solid-state dye-sensitized solar cells, finishingthe thesis with the following works specifically:(1) Assembled three kinds of solid-state dye-sensitized solar cells with differentmolecular weights P3HT. Transient photovoltage decay, electrochemical impedancespectroscopy, charge extraction together with light-assisted dielectric response measurementswere performed to study the effect of the molecular weight of P3HT on the performance ofsolid-state dye-sensitized solar cells. The results show that there is a non-uniform filtrationof P3HT with a high molecular weight into the TiO2mesoporous film.(2) The mechanism of the photocurrent generation and the role of P3HT in thesolid-state dye-sensitized solar cells have been discussed. The photoluminescence andincident photon-to-current conversion efficiency results show that both “dye-regenerating”mechanism and “electron-mediating” mechanism are present in the TiO2/Dye/P3HT devices.(3) Enhanced light harvesting in solid-state dye-sensitized solar cells with the porphyrindye, LD14. Although the mesoporous TiO2film in LD14device is only200nm thick, theshort circuit current density of LD14device, with a2.5%power conversion efficiency, istwice higher than Z907Na device.