Conformational engineering of co-sensitizers to retard back charge transfer for high-efficiency dye-sensitized solar cells
Conformational engineering of co-sensitizers to retard back charge transfer for high-efficiency dye-sensitized solar cells
复制标题
DOI：
10.1039/c3ta12714a
复制
发表时间：
2013-01-01
影响因子：
11.9
通讯作者：
Chen, Tao
中科院分区：
文献类型：
--
作者：
Chang, Shuai;Wang, Hongda;Chen, Tao
我们证明小分子（吩噻嗪基染料）在卟啉敏化的 TiO2 阳极表面上的后吸附具有双重作用：（1）大大延迟 TiO2 中的导带电子与电解质中的氧化物质（I-3（-））之间的逆反应；（2）增强太阳能电池的光谱响应。这两种效应最终使器件效率超过10%，优于相同条件下卟啉（7.4%）或吩噻嗪（8.2%）的单个染料敏化器件。实验分析表明，进入的小分子被吸附在卟啉染料的间隙位置，形成密集的表面堆积分子，从而阻止 I-3(-) 物质接近 TiO2 表面。由于多种钌基染料和卟啉基光敏剂具有相对较大的分子体积，因此该方法有望用于进一步提高这两类染料敏化器件的能量转换效率。
We demonstrate that the post-adsorption of small molecules (a phenothiazine-based dye) on the porphyrin-sensitized TiO2 anode surface plays dual roles: (1) to greatly retard the back reaction between conduction-band electrons in TiO2 and the oxidized species (I-3(-)) in the electrolyte and (2) to enhance the spectral response of solar cells. These two effects finally give rise to device efficiencies exceeding 10%, which are superior to those of individual dye-sensitized devices by either porphyrin (7.4%) or phenothiazine (8.2%) under the same conditions. Experimental analyses show that the incoming small molecules are adsorbed in the interstitial site of porphyrin dyes, forming densely surface packed molecules and thus impeding the I-3(-) species from approaching the TiO2 surface. Since a broad range of ruthenium-based dyes and porphyrin-based photo-sensitizers possess relatively large molecular volumes, this method is anticipated to be applicable for further improving the energy conversion efficiency of devices sensitized by these two classes of dyes.