Anatase titanium dioxide nanowire arrays were prepared by hydrothermally oxidizing titanium foils in aqueous alkali and transferred onto fluorinated tin oxide(FTO)glass for use as the photoanodes of front side illuminated dye-sensitized solar cells(DSCs).Electrochemical impedance spectroscopy(EIS)measurement was applied to compare the electron transport and recombination properties of DSCs using TiO2nanowire films and TiO2nanoparticle films as photoanodes.It was found that the nanowire array films possess smaller electron transport resistance(Rt)and larger electron diffusion length(Le)in the photoanodes,suggesting that the nanowire arrays can enhance the electron transport rate and have a potential to improve the charge collection efficiency of DSCs.
JIAO XingJianWANG XiaoLI XinCHEN HuiYuanWANG GangLI JianBaoLIN Hong
从高原格桑花和胡萝卜中提取天然染料花青素和β-胡萝卜素作为敏化剂,并组装染料敏化太阳能电池(DSC)。研究了提取的天然染料的光吸收性能、主要成分和共敏化方式,讨论了花青素和β-胡萝卜素的共敏化形式、比例、浓度和时间对DSC光电性能的影响。研究发现,花青素和β-胡萝卜素混合敏化时表现出明显的共敏化作用,而分层敏化时则共敏效果不明显。当花青素含量逐渐降低时,共敏化电池的短路电流和光电转换效率表现出先增大后减小的趋势,且共敏化的最佳体积比为1∶1,同时发现共敏化时间比通常少很多,最佳敏化时间为15min。最佳共敏化条件下组装的DSC的短路电流密度为0.725 m A/cm2,光电转换效率为0.267%,相比于花青素和β-胡萝卜素单独敏化时组装的DSC,短路电流分别提高了60%和505%,光电转换效率分别提高了51%和480%,这主要得益于共敏化后拓宽的光谱吸收范围。
