Lee, K.-M.K.-M.LeeChen, P.-Y.P.-Y.ChenHsu, C.-Y.C.-Y.HsuHuang, J.-H.J.-H.HuangHo, W.-H.W.-H.HoChen, H.-C.H.-C.ChenHo, K.-C.K.-C.HoKUO-CHUAN HO2018-09-102018-09-102009http://www.scopus.com/inward/record.url?eid=2-s2.0-59649111844&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/347913A poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine) (PProDOT-Et2) counter electrode prepared by electrochemical polymerization on a fluorine-doped tin oxide (FTO) glass substrate was incorporated in a platinum-free dye-sensitized solar cell (DSSC). The surface roughness and I-/I3- redox reaction behaviors based on PProDOT-Et2, poly(3,4-propylenedioxythiophene) (PProDOT), poly(3,4-ethylenedioxythiophene) (PEDOT), and sputtered-Pt electrodes were characterized, and their performances as counter electrodes in DSSCs were compared. Cells fabricated with a PProDOT-Et2 counter electrode showed a higher conversion efficiency of 7.88% compared to cells fabricated with PEDOT (3.93%), PProDOT (7.08%), and sputtered-Pt (7.77%) electrodes. This enhancement was attributed to increases in the effective surface area and good catalytic properties for I3- reduction. In terms of the film thickness effect, the fill factor was strongly dependent on the deposition charge capacity of the PProDOT-Et2 layer, but the aggregation of PProDOT-Et2 in thicker layers (>80 mC cm-2) resulted in decreases in JSC and the cell conversion efficiency. The charge transfer resistances (Rct1) of the PProDOT-Et2 counter electrodes had the lowest value of ∼18 Ω at a deposition charge capacity of 40 mC cm-2. These results indicate that films with high conductivity, high active surface area, and good catalytic properties for I3- reduction can potentially be used as the counter electrode in a high-performance DSSC. © 2008 Elsevier B.V. All rights reserved.Conducting polymer; Counter electrode; Dye-sensitized solar cells; PProDOT-Et2[SDGs]SDG7Charge transfer; Conducting polymers; Conductive plastics; Conversion efficiency; Electrodes; Fluorine; Ion exchange; Organic conductors; Organic polymers; Photoelectrochemical cells; Photovoltaic cells; Platinum; Polymeric glass; Polymers; Redox reactions; Reduction; Solar cells; Solar equipment; Surface roughness; Tin; Titanium compounds; Active surface areas; Catalytic properties; Cell conversion efficiencies; Charge capacities; Charge transfer resistances; Conducting polymer; Counter electrode; Dye-sensitized solar cells; Effective surface areas; Electrochemical polymerizations; Ethylenedioxythiophene; Fill factors; Fluorine-doped tin oxides; Glass substrates; High conductivities; Performance counters; PProDOT-Et2; Pt electrodes; Reaction behaviors; Thickness effects; Electrochemical electrodesjournal article10.1016/j.jpowsour.2008.11.075