Research On The Influence Of Interface Modification By Additive In Electrolyte&DSC’s Photovoltaic Properties

Researches on new structures and materials are important topics in the fields ofdye-sensitized solar cells （DSC）. This paper focused on the scientific problems aboutthe interface modification properties for the additives in electrolyte. After introducingMg（OOCCH₃）₂and MMT as additives in DSC’s electrolyte, this paper aims at thefollowing scientific problems: the interface modification for Mg（OOCCH₃）₂as anadditive in quasi-solid electrolyte and its photovoltaic effect; the interface intercalationmodification for MMT as an additive in quasi-solid electrolyte and its photovoltaiceffect. The main results and conclusions are as follows:（1）Mg（OOCCH₃）₂was introduced as an additive in PEO gel electrolyte. Theinfluence at the TiO₂/dye/electrolyte interface was studied by electrochemicalimpedance spectra technique, normalized transient photovoltaic spectra and dark currenttechnique. The results indicated that Mg（OOCCH₃）₂in the electrolyte could obviouslydecrease the electron recombination. The I-V test result showed that, at a certain rangeof ratio, Mg（OOCCH₃）₂could obviously increase the photovoltage and photocurrent.Finally, the results of conductivity and IPCE testing showed that the mechanism forMg（OOCCH₃）₂was modifying the dye and thus increasing the electron injectionefficiency at the excited state.（2）After adding MMT to PEO gel electrolyte, the steady-state current-voltagetechnique result showed that the diffusion coefficient of I3-was accelerated in a certainrange. The influence for dark current of DSC was tested by electrochemical impedancespectra technique, normalized transient photovoltage spectra. It revealed that theelectron recombination was obviously decreased. The I-V testing of DSC revealed thatthe photovoltage and photocurrent were both enhanced in the presence of MMT. Furthertestings of FTIR, Fluorescence Spectrometry and XRD showed that MMT/NMBInanocomposites with intercalated structure were formed, resulting in that theinterlamellar spacing of MMT was unfolded. The results of IMPS and IMVS showedthat MMT after NMBI’s intercalation could further decrease the dark current andaccelerate the diffusion coefficient of I3-.