Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, People's Republic of China.
ACS Nano. 2010 Jun 22;4(6):3482-8. doi: 10.1021/nn100449w.
This paper presents a systematic investigation on the incorporation of chemical exfoliation graphene sheets (GS) in TiO(2) nanoparticle films via a molecular grafting method for dye-sensitized solar cells (DSSCs). By controlling the oxidation time in the chemical exfoliation process, both high conductivity of reduced GS and good attachment of TiO(2) nanoparticles on the GS were achieved. Uniform GS/TiO(2) composite films with large areas on conductive glass were prepared by electrophoretic deposition, and the incorporation of GS significantly improved the conductivity of the TiO(2) nanoparticle film by more than 2 orders of magnitude. Moreover, the power conversion efficiency for DSSC based on GS/TiO(2) composite films is more than 5 times higher than that based on TiO(2) alone, indicating that the incorporation of GS is an efficient means for enhancing the photovoltaic (PV) performance. The better PV performance of GS/TiO(2) DSSC is also attributed to the better dye loading of GS/TiO(2) film than that of TiO(2) film. The effect of GS content on the PV performances was also investigated. It was found that the power conversion efficiency increased first and then decreased with the increasing of GS concentration due to the decrease in the transmittance at high GS content. Further improvements can be expected by fully optimizing fabrication conditions and device configuration, such as increasing dye loading via thicker films. The present synthetic strategy is expected to lead to a family of composites with designed properties.
本文通过分子接枝法对 TiO(2) 纳米粒子薄膜进行了化学剥离石墨烯片（GS）的系统研究，用于染料敏化太阳能电池（DSSC）。通过控制化学剥离过程中的氧化时间，实现了还原 GS 的高导电性和 TiO(2)纳米粒子在 GS 上的良好附着。通过电泳沉积制备了具有大面积导电玻璃的均匀 GS/TiO(2)复合薄膜，GS 的掺入使 TiO(2)纳米粒子薄膜的电导率提高了两个数量级以上。此外，基于 GS/TiO(2)复合薄膜的 DSSC 的功率转换效率比基于 TiO(2)的 DSSC 高 5 倍以上，表明 GS 的掺入是提高光伏（PV）性能的有效手段。GS/TiO(2) DSSC 的更好的 PV 性能还归因于 GS/TiO(2)薄膜比 TiO(2)薄膜具有更好的染料负载。还研究了 GS 含量对 PV 性能的影响。发现由于在高 GS 含量下透光率降低，功率转换效率随着 GS 浓度的增加先增加后降低。通过进一步优化制备条件和器件结构，例如通过更厚的薄膜增加染料负载，可以进一步提高效率。预计这种合成策略将导致一系列具有设计性能的复合材料。
