Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, USA.
Inorg Chem. 2013 Jun 3;52(11):6752-64. doi: 10.1021/ic4010856. Epub 2013 May 21.
We present the first analysis of performance of hydroxamate linkers as compared to carboxylate and phosphonate groups when anchoring ruthenium-polypyridyl dyes to TiO2 surfaces in dye-sensitized solar cells (DSSCs). The study provides fundamental insight into structure/function relationships that are critical for cell performance. Our DSSCs have been produced by using newly synthesized dye molecules and characterized by combining measurements and simulations of experimental current density-voltage (J-V) characteristic curves. We show that the choice of anchoring group has a direct effect on the overall sunlight-to-electricity conversion efficiency (η), with hydroxamate anchors showing the best performance. Solar cells based on the pyridyl-hydroxamate complex exhibit higher efficiency since they suppress electron transfer from the photoanode to the electrolyte and have superior photoinjection characteristics. These findings suggest that hydroxamate anchoring groups should be particularly valuable in DSSCs and photocatalytic applications based on molecular adsorbates covalently bound to semiconductor surfaces. In contrast, analogous acetylacetonate anchors might undergo decomposition under similar conditions suggesting limited potential in future applications.
我们首次分析了在染料敏化太阳能电池（DSSC）中，将钌-多吡啶染料固定在 TiO2 表面时，羟肟酸配体与羧酸盐和膦酸盐的性能比较。该研究深入探讨了对电池性能至关重要的结构/功能关系。我们的 DSSC 使用新合成的染料分子制备，并通过结合实验电流密度-电压（J-V）特性曲线的测量和模拟进行了表征。我们表明，锚固基团的选择对整体太阳光到电能的转换效率（η）有直接影响，其中羟肟酸锚固基团的性能最佳。基于吡啶-羟肟酸配合物的太阳能电池具有更高的效率，因为它们抑制了从光阳极到电解质的电子转移，并且具有更好的光电注入特性。这些发现表明，在基于与半导体表面共价结合的分子吸附剂的 DSSC 和光催化应用中，羟肟酸锚固基团应该特别有价值。相比之下，类似的乙酰丙酮酸盐锚固基团在类似条件下可能会发生分解，这表明它们在未来的应用中潜力有限。
