石墨烯纳米片对电极染料敏化太阳电池

Dye-Sensitized Solar Cells Employing Graphene Nanosheets as Counter Electrode

将经球磨处理的鳞片石墨作为前驱体采用氧化还原法制备石墨烯纳米片(GNs),考察晶体结构变化。将GNs作为催化材料应用于染料敏化太阳电池(DSCs),探讨GNs对电极经热处理对器件光电性能的影响。结果表明,采用球磨对鳞片石墨进行预处理,能改进GNs的晶体结构,即厚度减薄、晶面间距d(002)增大。晶体结构改进后的GNs具有更高的催化活性和更强的氧化还原对扩散能力,相应地,DSCs的转换效率得到大幅度的提升。GNs对电极经热处理,能进一步提高对电极的催化活性以及氧化还原对扩散能力,最终促使器件的转换效率从1.17%增加到1.54%,增幅达到31.3%。

Ball-milled flake graphite is first employed as precursor to synthesize graphene nanosheets （GNs） by a technique of oxidation-reduction to study the change of crystal structure. The GNs are then used as catalytic materials for counter electrode in dye-sensitized solar cells （DSCs）, and the influence of the succeeding heat treatment of the GNs counter electrode on the photovoltaic properties of the device is finally investigated. Results show that the crystal structure of the GNs is improved by introducing the ball-milling of flake graphite, the thickness of the GNs is reduced and the distance dcoo2〉 of graphene layer is increased. Compared with the GNs prepared from natural flake graphite, the improved GNs as catalytic materials have higher catalytic activity and stronger capability of electrolyte diffusion, resulting in significant improvement in the efficiency of the DSCs. Through the heat treatment, the catalytic activity and the electrolyte diffusion capability of the GNs counter electrode are obviously strengthened, and the efficiency of the device is raised from 1.17% to 1.54% with an increment of 31.3%.