title: Thermally-induced single-crystal-to-single-crystal transformations from a 2D two-fold interpenetrating square lattice layer to a 3D four-fold interpenetrating diamond framework and its application in dye-sensitized solar cells.
abstract: In this work, a rare 2D → 3D single-crystal-to-single-crystal transformation (SCSC) is observed in metal-organic coordination complexes, which is triggered by thermal treatment. The 2D two-fold interpenetrating square lattice layer [Cd(IBA)2]n (1) is irreversibly converted into a 3D four-fold interpenetrating diamond framework {[Cd(IBA)2(H2O)]·2.5H2O}n (2) (HIBA = 4-(1H-imidazol-1-yl)benzoic acid). Consideration is given to these two complexes with different interpenetrating structures and dimensionality, and their influence on photovoltaic properties are studied. Encouraged by the UV-visible absorption and HOMO-LUMO energy states matched for sensitizing TiO2, the two complexes are employed in combination with N719 in dye-sensitized solar cells (DSSCs) to compensate absorption in the ultraviolet and blue-violet region, offset competitive visible light absorption of I3(-) and reducing charge the recombination of injected electrons. After co-sensitization with 1 and 2, the device co-sensitized by 1/N719 and 2/N719 to yield overall efficiencies of 7.82% and 8.39%, which are 19.94% and 28.68% higher than that of the device sensitized only by N719 (6.52%). Consequently, high dimensional interpenetrating complexes could serve as excellent co-sensitizers and have application in DSSCs.
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China. fanruiqing@hit.edu.cn ylyang@hit.edu.cn.
authors.forename: Song
authors.initials: S
authors.lastname: Gao
authors.forename: Rui Qing
authors.initials: RQ
authors.lastname: Fan
authors.forename: Xin Ming
authors.initials: XM
authors.lastname: Wang
authors.forename: Li Guo
authors.initials: LG
authors.lastname: Wei
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.forename: Xi
authors.initials: X
authors.lastname: Du
authors.forename: Kai
authors.initials: K
authors.lastname: Xing
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Yu Lin
authors.initials: YL
authors.lastname: Yang