Bai Yu, Cao Yiming, Zhang Jing, Wang Mingkui, Li Renzhi, Wang Peng, Zakeeruddin Shaik M, Grätzel Michael
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Nat Mater. 2008 Aug;7(8):626-30. doi: 10.1038/nmat2224. Epub 2008 Jun 29.
Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability. However, the cells with the best performance use volatile solvents in their electrolytes, which may be prohibitive for outdoor solar panels in view of the need for robust encapsulation. Solvent-free room-temperature ionic liquids have been pursued as an attractive solution to this dilemma, and device efficiencies of over 7% were achieved by using some low-viscosity formulations containing 1-ethyl-3-methylimidazolium thiocyanate, selenocyanate, tricyanomethide or tetracyanoborate. Unfortunately, apart from tetracyanoborate, all of these low-viscosity melts proved to be unstable under prolonged thermal stress and light soaking. Here, we introduce the concept of using eutectic melts to produce solvent-free liquid redox electrolytes. Using a ternary melt in conjunction with a nanocrystalline titania film and the amphiphilic heteroleptic ruthenium complex Z907Na (ref. 10) as a sensitizer, we reach excellent stability and an unprecedented efficiency of 8.2% under air-mass 1.5 global illumination. Our results are of importance to realize large-scale outdoor applications of mesoscopic DSCs.
基于有机光电材料的低成本激子太阳能电池作为传统无机光伏器件的潜在替代品正受到越来越多的关注。在这个快速发展的领域中，染料敏化太阳能电池（DSC）目前已实现了11.1%的最高验证效率（参考文献2）以及出色的稳定性。然而，性能最佳的电池在其电解质中使用挥发性溶剂，鉴于需要坚固的封装，这对于户外太阳能电池板来说可能是个问题。无溶剂室温离子液体已被视为解决这一困境的有吸引力的方案，通过使用一些含有1-乙基-3-甲基咪唑硫氰酸盐、硒氰酸盐、三氰甲基化物或四氰硼酸盐的低粘度配方，器件效率达到了7%以上。不幸的是，除了四氰硼酸盐外，所有这些低粘度熔体在长时间热应力和光照下都被证明是不稳定的。在此，我们引入了使用低共熔物来制备无溶剂液体氧化还原电解质的概念。将三元熔体与纳米晶二氧化钛薄膜以及两亲性异质钌配合物Z907Na（参考文献10）作为敏化剂结合使用，在空气质量1.5全球光照下，我们实现了出色的稳定性和前所未有的8.2%的效率。我们的结果对于实现介观DSC的大规模户外应用具有重要意义。
