Photovoltaic Performances Of Bifacial Dye-sensitized Solar Cells With Non-Platinum Counter Electrode

Counter electrode is an important part to improve the conversion efficiency and reduce costs of Dye-Sensitized Solar Cells(DSCs).If the counter electrode is transparent or semitransparent, a bifacial DSCs can obtained higher light harvesting efficiency because of its capability of utilizing the incident light from both sides, which can further bring down the cost of energy production and to enlarge its applications. In this study, we focused on the bifacial photovoltaic performances of DSCs with the transparent non-platinum carbon and PANI counter electrodes and the influence of high electron mobility ZnO insert layer between the conductive glass(fluorine-doped tin oxide, FTO) and the catalyst layer.Transparent carbon counter electrodes:the one-transparent carbon catalytic film on FTO prepared by in-stiu methed with poly(ethylene glycol)800(PEG800) as the carbon source was used as counter electrode for bifacial DSCs, The UV-Vis spectra confirm that all the carbon counter electrodes have excellent transparency with transmittance over 70% in the visible range. At the same spin coating rate, solution made of acetylacetone and isopropanol is more suitable for PEG800 than solution made of acetylacetone and acetone, for the front carbon counter electrode have higher transparency and catalytic activity, and the corresponding DSCs have better conversion efficiencies under rear- and front-side illumination(bifacial conversion efficiencies).The catalytic activity of carbon counter electrodes and the bifacial conversion efficiencies of DSCs have an inversely relationship to spin coating rate. Different surface roughness is the main factor for the different performances of carbon counter electrodes. The ratio of bifacial conversion efficiencies is over 80%, higher than the same photoanode employing a Pt counter electrode of 44%.Transparent PANI counter electrodes:the PANI counter electrodes made by dosing, spin coating, pyrolysis processes with PANI was used as counter electrode for bifacial DSCs, The UV-Vis spectra confirm that all the PANI counter electrodes have excellent transparency.Electrodes made of solution m-cresol with transmittance about 80% in the visible range, and made of solution chloroform are little lower. The ratio of bifacial conversion efficiencies is about 77%~98%, higher than the same photoanode employing a Pt counter electrode of 44%.At the same spin coating rate, solution m-cresol is more suitable for PANI than solution chloroform,for the front PANI counter electrode have higher transparency and catalytic activity, and the corresponding DSCs have better bifacial conversion efficiencies. The catalytic activity of PANI counters electrodes and the bifacial conversion efficiencies.ZnO insert layer: explore the influence of ZnO insert layer on the photovoltaic performances of DSCs.The UV-Vis spectra confirm that carbon/ZnO counter electrodes have lower transparency about 30%~50%,its light transmission properties of wavelength is different of electrode without insert ZnO layer. PANI/ZnO counter electrodes' light transmittance is about 70%~80%,its light transmission properties of wavelength is almost same of electrode without insert ZnO layer.The DSCs' bifacial conversion efficiencies increase at first than decline with spin-coating rate. When spin coating rate were less than 1500 rpm, the DSCs have better bifacial conversion efficiencies.