title: Efficient triarylamine-perylene dye-sensitized solar cells: influence of triple-bond insertion on charge recombination.
abstract: We synthesize two new metal-free donor-acceptor organic dyes (C266 and C267) featuring a N-annulated perylene block. Owing to the improved coplanarity of conjugated units as well as the prolonged conjugation upon inserting a triple bond between the triarylamine and perylene segments, the C267 dye exhibits a slightly red-shifted absorption peak and an enhanced maximum molar absorption coefficient with respect to its reference dye C266, leading to an improved photocurrent output in dye-sensitized solar cells. However, the triple-bond introduction also brings forth an over 100 mV reduced open-circuit photovoltage owing to faster interfacial charge recombination, which presents a clear correlation with a reduced mean thickness of self-assembled dye layer on titania as revealed by X-ray reflectivity measurements. The C266 dye, albeit with a relatively weaker light-harvesting capacity, displays a higher power conversion efficiency of 9.0% under the 100 mW cm(-2), simulated AM1.5G sunlight.
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun, 130022, China.
authors.forename: Cancan
authors.initials: C
authors.lastname: Yan
authors.forename: Wentao
authors.initials: W
authors.lastname: Ma
authors.forename: Yameng
authors.initials: Y
authors.lastname: Ren
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
keywords: charge recombination; organic dye; perylene; solar cell