Abstract A dominant interfacial recombination pathway in the dye sensitized solar cell (DSSC) was suppressed by coating graphene oxide (GO) on the titanium dioxide (TiO2) nanoparticle layer via the electrophoretic deposition (EPD) method. DSSC utilizing 5 min coating of GO by EPD on TiO2 nanoparticle layer showed 5% enhancement in the photo-conversion efficiency (from 5.7% to 6.0%), and 5% enhancement in the short circuit current density (from 11.4 mA/cm2 to 12.0 mA/cm2) in comparison with reference DSSCs which did not use GO on TiO2. GO coating on TiO2 is attributed to the efficient suppression of the photo-generated electron–hole recombination at the TiO2/dye/electrolyte interfaces. The further increase in the thickness of GO (10- and 20-min EPD coating) on the TiO2 nanoparticle layer impeded the charge transport as the performance of the respective DSSCs was significantly affected. It suggested that the probability of photo-generated electron tunneling from dye to TiO2 was suppressed by increasing the thickness of the GO layer. Presented results assure that GO can be considered as a competitive surface passivation candidate for nanostructured excitonic solar cells.

中文翻译：

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用于染料敏化太阳能电池的二氧化钛电泳氧化石墨烯表面钝化

摘要 通过电泳沉积 (EPD) 方法将氧化石墨烯 (GO) 涂覆在二氧化钛 (TiO2) 纳米颗粒层上，抑制了染料敏化太阳能电池 (DSSC) 中的主要界面复合途径。DSSC 在 TiO2 纳米颗粒层上通过 EPD 涂覆 GO 5 分钟，其光转换效率提高了 5%（从 5.7% 到 6.0%），短路电流密度提高了 5%（从 11.4 mA/cm2 到 12.0 mA/cm2) 与未在 TiO2 上使用 GO 的参考 DSSC 进行比较。TiO2 上的 GO 涂层归因于有效抑制了 TiO2/染料/电解质界面处的光生电子-空穴复合。TiO2 纳米颗粒层上 GO（10 和 20 分钟 EPD 涂层）厚度的进一步增加阻碍了电荷传输，因为各个 DSSC 的性能受到显着影响。这表明通过增加 GO 层的厚度可以抑制光生电子从染料隧穿到 TiO2 的可能性。所呈现的结果确保 GO 可被视为纳米结构激子太阳能电池的竞争性表面钝化候选物。