Understanding and Promoting Molecular Interactions and Charge Transfer in Dye-Mediated Hybrid Photovoltaic Materials
详细信息 查看全文
- 作者：Tamar Segal-Peretz ; Justin P. Jahnke ; Alexander Berenson ; Lior Neeman ; Dan Oron ; Aaron J. Rossini ; Bradley F. Chmelka ; Gitti L. Frey
- 刊名：Journal of Physical Chemistry C
- 出版年：2014
- 出版时间：November 6, 2014
- 年：2014
- 卷：118
- 期：44
- 页码：25374-25391
- 全文大小：796K
- ISSN：1932-7455
文摘
The performances of hybrid organic鈥搃norganic photovoltaics composed of conjugated polymers and metal oxides are generally limited by poor electronic coupling at hybrid interfaces. In this study, physicochemical interactions and bonding at the organic鈥搃norganic interfaces are promoted by incorporating organoruthenium dye molecules into self-assembled mesostructured conjugated polymer鈥搕itania composites. These materials are synthesized from solution in the presence of surfactant structure-directing agents (SDA) that solubilize and direct the nanoscale compositions and structures of the conjugated polymer, dye, and inorganic precursor species. Judicious selection of the SDA and dye species, in particular, exploits interactions that direct the dye species to the inorganic鈥搊rganic interfaces, leading to significantly enhanced electronic coupling, as well as increased photoabsorption efficiency. This is demonstrated for the hydrophilic organoruthenium dye N3, used in conjunction with alkyleneoxide triblock copolymer SDA, polythiophene conjugated polymer, and titania species, in which the N3 dye species are localized in molecular proximity to and interact strongly with the titania framework, as established by solid-state NMR spectroscopy. In contrast, a closely related but more hydrophobic organoruthenium dye, Z907, is shown to interact more weakly with the titania framework, yielding significantly lower photocurrent generation. The strong SDA-directed N3-TiOx interactions result in a significant reduction of the lifetime of the photoexcited state and enhanced macroscopic photocurrent generation in photovoltaic devices. This study demonstrates that multicomponent self-assembly can be harnessed for the fabrication of hierarchical materials and devices with nanoscale control of chemical compositions and surface interactions to improve photovoltaic properties.