电荷分离型染料敏化剂：从抑制聚集到利用聚集（英文）

【作者】 周雪琴； 许芳； 巩鹍； 王丽昌； 李巍； 刘东志；

【机构】 天津大学化工学院； School of Chemical and Biomolecular Sciences, Southern Illinois University；

【摘要】 The aggregation-induced excited-state quenching(AIESQ) effect is a common issue for organic photovoltaic materials, which would debilitate the charge separation and transportation of solid organic photovoltaic materials(OPMs), counting against the cell performance. The aggregate structure of organic dyes in the organic solar cell(OSC) varies with the processing and application conditions, altering the photophysical processes together with the degree of AIESQ effect which finally induces variant cell performance. In various OSCs, only the dye molecules adsorbed on the titanium oxide(TiO2) in dye-sensitized solar cells(DSSCs) are quasi-dimentional, i.e. nearly monolayer.[1] In comparison with other organic materials in other OSCs with three-dimensional multilayers, the absorbed sensitizers in DSSCs are more conducive to reveal the aggregation effect on photovoltaic performances of cells. Our literature survey[2] reveals that the vast majority of dye sensitizers suffer from the AIESQ effect on account of intermolecular electron transfer, thus greatly diminishing the interfacial electron injection efficiency and the device efficiency. Hence, extensive studies are devoted to design sensitizers and device preparation process such as co-sensitization to suppress dye aggregation on the TiO2 film. It is assumed whether one can suppress the AIESQ effect by special designed molecules and utilize dye aggregation to boost the photovoltaic performance of DSSCs. Herein, we put forward the concept of charge-separated(CS) dye sensitizers which have been characterized with prominent CS feature. We report the greatly improved interfacial electron injection efficiency[3] and efficient suppression of AIESQ in aggregated CS dye sensitizers[4], which result in a boosted photocurrent as well as the efficiency of DSSCs because of the enhanced light harvest ability by aggregated dyes.Satisfactorily, the efficiency of dye TEBT-Pyc with a λabs max of 439 nm reaches up to 8.01%,even slightly better than that(7.89%) of the standard cell based on N719(with a λabs max of 532nm).更多还原

【Abstract】 The aggregation-induced excited-state quenching(AIESQ) effect is a common issue for organic photovoltaic materials, which would debilitate the charge separation and transportation of solid organic photovoltaic materials(OPMs), counting against the cell performance. The aggregate structure of organic dyes in the organic solar cell(OSC) varies with the processing and application conditions, altering the photophysical processes together with the degree of AIESQ effect which finally induces variant cell performance. In various OSCs, only the dye molecules adsorbed on the titanium oxide(TiO2) in dye-sensitized solar cells(DSSCs) are quasi-dimentional, i.e. nearly monolayer.[1] In comparison with other organic materials in other OSCs with three-dimensional multilayers, the absorbed sensitizers in DSSCs are more conducive to reveal the aggregation effect on photovoltaic performances of cells. Our literature survey[2] reveals that the vast majority of dye sensitizers suffer from the AIESQ effect on account of intermolecular electron transfer, thus greatly diminishing the interfacial electron injection efficiency and the device efficiency. Hence, extensive studies are devoted to design sensitizers and device preparation process such as co-sensitization to suppress dye aggregation on the TiO2 film. It is assumed whether one can suppress the AIESQ effect by special designed molecules and utilize dye aggregation to boost the photovoltaic performance of DSSCs. Herein, we put forward the concept of charge-separated(CS) dye sensitizers which have been characterized with prominent CS feature. We report the greatly improved interfacial electron injection efficiency[3] and efficient suppression of AIESQ in aggregated CS dye sensitizers[4], which result in a boosted photocurrent as well as the efficiency of DSSCs because of the enhanced light harvest ability by aggregated dyes.Satisfactorily, the efficiency of dye TEBT-Pyc with a λabs max of 439 nm reaches up to 8.01%,even slightly better than that(7.89%) of the standard cell based on N719(with a λabs max of 532nm).更多还原