Porphyrin Assembly with Fullerenes for Photovoltaic Applications
- PDF / 899,480 Bytes
- 3 Pages / 612 x 792 pts (letter) Page_size
- 49 Downloads / 198 Views
1091-AA05-64
Porphyrin Assembly with Fullerenes for Photovoltaic Applications Takashi Sagawa1, Osamu Yoshikawa1, Hirokuni Jintoku2, Makoto Takafuji2, Hirotaka Ihara2, and Susumu Yoshikawa1 1 Institute of Advanced Energy, Kyoto University, Gokasho, Uji, 611-0011, Japan 2 Department of Applied Chemistry and Biochemistry, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan ABSTRACT Morphologically controllable thin-films of a zinc-containing tetraphenylporphyrin (ZnTPP) combined with an L-glutamide lipid has been fabricated and complexation of ZnTPP with fullerene was examined for organic thin-film solar cells, which gave 3 times enhancement of solar energy-to-electricity conversion efficiency through chlorobenzene-annealing in comparison with the conversion efficiency of untreated one. INTRODUCTION Molecular assemblies of porphyrin-derivatives are key-compounds in nature since they play important roles for light-harvesting and energy migration in photosynthesis [1]. Therefore, highly ordered assemblies of porphyrins are widely applicable and promising for electronic devices as light-harvesting molecular wires. In this context, we have previously reported on a mixed system composed of pyrene- and protoporphyrin IX-functionalized L-glutamide derivatives for energy transfer [2]. In spite of various types of functionalized porphyrin assemblies [3], only a few reports had been referred their applications for photovoltaic cells [4]. We report herein a fabrication of a molecular gel system of porphyrin combined with a Lglutamide-derived lipid with double long chain alkyl groups as a lipophilic part and tetraphenylporphyrin (TPP) as a functional head group {abbreviated as 2C12-L-Gln-TPP (1) and zinc-inserted 2C12-L-Gln-ZnTPP (2)}. Through the intermolecular amide hydrogen bonding and π-π* stacking of the porphyrin lead to form fibrous networks in gel state in hydrophobic organic solvent. Our system provides organic thin-film solar cells and enables to enhance their cell efficiencies through the morphological regulation of 2 by varying the conditions of temperature, concentration, solvent, and so on during the fabrication processes of the thin-films.
1: M = 2H, 2: M = Zn
EXPERIMENT An L-glutamide-derived compound with a porphyrin moiety (2C12-L-Gln-TPP) wa s synthesized by the amide-bonding formation of 5-(4-carboxyphenyl)-10, 15, 20-triphenyl-21H, 23H-porphine with N’,N-didodecyl L-glutamide according to the reported procedures [5] with slight modification. Resulting species of 1 and 2 were confirmed by elemental analysis, UV/Vis, FT-IR and 1H-NMR spectroscopies. For solar cell fabrication [6], commercially available indium-tin oxide (ITO) on glass substrates were used. The substrate was sonicated with purified water, acetone, and ethanol, respectively. After the blow-drying, poly(ethylene dioxythiophene) doped with polystyrene sulfonic acid (PEDOT:PSS) was spin-coated at 3000 rpm onto the substrate. Active layer of the blended 2 and C60 or (6,6)-phenyl C61 butyric acid methyl ester (PCBM) in chlorobenzene was
Data Loading...
