An insight into the organic dye aggregates effect on the spectra and intermolecular electronic coupl

• 作 者: ShuaiFeng;Quan-songLi;Ze-shengLi;
• 机 构: Key Laboratory of Cluster Science of Ministry of Education,School of Chemistry,Beijing Institute of
• 出 处: 第十二届全国量子化学会议
• 发表日期: 2014年期

　　Solar energy,a renewable energy source,is generally considered as the most promising way tosolve the global energy crisis.Since O Regan and Gra tzel announced a high solar energyconversion efficiency(η)above 7%in 1991,1 Dye-sensitized solar cells(DSSCs)have attractedsignificant attention as potential low-cost photovoltaic devices.As one of the most criticalcomponents in DSSCs,dye-sensitizers play a key role in the power conversion efficiency as well asthe device stability,which is responsible for light capturing and the generation of electric charges.2A great deal of promising metal-free dyes3 have been designed to employ in DSSC applications,owing to more merits such as facile structure modification,high extinction coefficients and low costcompared to metal complexes.However,due to the strong attractive force between organicsensitizers,they have a strong tendency to aggregate in solution or at the solid-liquid interfacewhen the sensitizers adsorbed onto a nanocrystalline TiO2 surface,with typical coverage values ofabout one molecule per nm2.4 The consequent electrostatic and noncovalent interactions of dyemolecules with the semiconductor and with adjacent molecules may lead to the formation of anordered assembly of dye aggregates.