石墨烯纳米薄片的制备及其作为DSCs对电极的光电性能

采用氧化还原法制备出多层结构的石墨烯纳米薄片（GNs）,分析了还原阶段水浴时间对GNs晶体结构的影响,着重探讨了GNs作为染料敏化太阳电池（DSCs）对电极催化层的光电性能及阻抗特征。结果表明,还原阶段水浴反应时间为24h时制备出的GNs平均层数最薄,平均厚度只有7层,将该反应时间制备出的GNs对电极组装成DSCs后,其短路电流（JSC）及填充因子（FF）明显地比石墨和氧化石墨（GO）对电极组装成DSCs的JSC和FF要高,因此使得其转换效率达到最好,为1.17%,比石墨和氧化石墨（GO）对电极分别增加了0.175%和1.034%。阻抗分析发现,GNs对电极的串阻（Rs）明显的减小,从而使得GNs作为染料敏化太阳电池（DSCs）对电极催化层的光电性能达到最佳。

The preparation of graphene nanosheets and its photovoltaic performances

In this paper,the graphene nanosheets（GNs） of multi-layer structure is prepared by oxidation reduction,the time of bath reaction in the moment of reduction effect on crystal structure of GNs is analysed,and photovoltaic performances and impedance characteristic of GNs as a counter electrode catalytic layer of dye-sensitized solar cells（DSCs） are emphatically discussed.The results show that the average layer of GNs is thinnest when the time of bath reaction in the moment of reduction is 24 hours,the average thinness being only 7 layers,after the GNs counter electrode which is prepared in this reaction time is assembled into DSCs,the short-circuit current（JSC） and fill factor（FF） are evidently better than the two DSCs which are assembled by graphite and graphite oxide（GO） counter electrodes,so its conversion efficiency is best,being 1.17%,increasing by 0.175% and 1.034% respectively than graphite and GO counter electrodes.Impedance analysis found that the series resistance（RS） of GNs counter electrode decreased significantly,making photovoltaic performances of GNs as a counter electrode catalytic layer of DSCs reach the best condition.