Evolution of the Excited‐State Dynamics of 2H‐Dinaphthopentacene Based Dyes in Dye‐Sensitized Solar Cells: From Chromophoric Core to Ultimate Dye. Issue 9 (29th June 2018)

• Record Type: Journal Article
• Authors: Liu, Jiao; Ren, Yameng; Zhang, Min; Dong, Xiandui
• Is Part Of: Solar RRL. Volume 2:Issue 9(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-06-29
• Subjects: charge transfer -- excited‐state dynamics -- organic dyes -- solar cells; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.201800119
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : The excited‐state evolution property of organic sensitizers plays a vital role in the interfacial exciton dissociation yield and ultimate power output of an organic dye‐sensitized solar cell. In this paper, we select two 2 H ‐dinaphthopentacene‐based organic donor–acceptor dyes as well as their composition segments and scrutinize the evolution of the excited‐state dynamics of organic materials from the 2 H ‐dinaphthopentacene core to its derivatives by sequentially tethering an auxiliary donor diarylamine, and an electron acceptor, 4‐(7‐ethynylbenzo[ c ][1, 2, 5]thiadiazol‐4‐yl)benzoic acid. Time‐resolved spectroscopy measurements and density functional theory calculations show that the degree of intramolecular photoinduced charge transfer plays a crucial role in determining the lifetime of the equilibrium excited‐state. Moreover, both the 2 H ‐dinaphthopentacene chromophore core and its derivatives have an obvious dynamic Stokes shift in toluene, which is also observed for ultimate dyes grafted on oxide films, indicating the occurrence of a large energy relaxation from the optically generated hot excited‐state to the equilibrium excited‐state. This large energy loss leads to a broad time scale for electron injection, which should be carefully manipulated for future dye and device development. Abstract : The excited‐state dynamics evolution of 2 H ‐dinaphthopentacene‐based organic materials from chromophoric core to ultimate dye is scrutinized based upon femtosecond fluorescence up‐conversion and time‐correlated single photon counting measurements. Photoluminescence quantum yield measurements and density functional theory calculations are performed to understand the origin of the energy‐gap independent lifetime of equilibrium excited‐state.