Squaraine Dyes with Pyrylium and Thiopyrylium Components for Harvest of Near Infrared Light in Dye-Sensitized Solar Cells
Squaraine Dyes with Pyrylium and Thiopyrylium Components for Harvest of Near Infrared Light in Dye-Sensitized Solar Cells
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DOI：
10.1021/jp412553z
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发表时间：
2014-04
影响因子：
3.7
通讯作者：
Takeshi Maeda;Shohei Nitta;Hidekazu Nakao;S. Yagi;H. Nakazumi
中科院分区：
文献类型：
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作者：
Takeshi Maeda;Shohei Nitta;Hidekazu Nakao;S. Yagi;H. Nakazumi
合成了含吡喃或硫代吡喃的不对称方酸菁染料，研究了它们的光吸收性能和作为染料敏化太阳能电池敏化剂的性能。2，6-二叔丁基-4-甲基吡喃鎓盐和硫代吡喃鎓盐与方酸丁酯缩合得到相应的半方酸盐。半菁鎓与含羧基的吲哚鎓反应得到目标不对称染料。它们在溶液中和二氧化钛表面的远红外和近红外区域表现出强烈的吸收。电化学测量结果表明，它们的氧化电位是中等偏高，虽然电子注入从激发的染料到二氧化钛导带是vertically允许的。因此，吡喃鎓和噻吡喃鎓组分将吸光度推入更长的波长区域，并使这些染料的最高占据分子轨道（HOMO）处于向上的水平。分子轨道计算表明，电子分布模型。
Unsymmetrical squaraine dyes bearing pyrylium or thiopyrylium components were synthesized, and their light-absorbing properties and performance as sensitizer in dye-sensitized solar cells were investigated. Condensations of 2,6-di-tert-butyl-4-methylpyrylium and thiopyrylium salt with butyl squarate afforded corresponding semisquaryliums. The semisquaryliums were reacted with indolenium with carboxyl group to give target unsymmetrical dyes. They exhibited intense absorption in the far-red and near-infrared region in solution and on the TiO2 surface. Electrochemical measurements revealed that their oxidation potentials were moderately high although electron injection from the excited dyes to the TiO2 conduction band was thermodynamically permitted. Thus, pyrylium and thipyrylium components push absorbance into longer wavelength region as well as bring the highest occupied molecular orbitals (HOMOs) of these dyes in the upward level. A molecular-orbital calculation indicated that the electron distribution m...