[13p-A34-1~6] Material processing using magnetic field effect on feeble magnetic

[13p-A34-4] Fabrication of Photofunctional Nanomaterials due to Magnetic Control of Photophysical Properties

〇Hiroaki Yonemura¹, Tomoki Niimi², Yuji Naka², Mitsuhiko Nishino², Yasutaka Tomiyama³, Sunao Yamada¹ (1.Faculty of Engineering, Kyushu Univ.,, 2.Graduate School of Engineering, Kyushu Univ., 3.School of Engineering, Kyushu Univ.)

Keywords:Magnetic Field Effect, Photoelectric Conversion, Photon Upconversion

Zinc-porphyrin(ZnP)–viologen(V) linked compound (ZnP(6)V)–silver nanoparticle (AgNP) composite films was fabricated by combining electrostatic layer-by-layer adsorption and the Langmuir–Blodgett method. The photocurrents in ZnP(6)V–AgNP composite films were larger than those in ZnP(6)V films, and were much larger than those in ZnP films as a reference. The photocurrents in ZnP(6)V–AgNP composite films and ZnP(6)V films are also enhanced by the application of a magnetic field. The magnitude of the magnetic field effects (MFEs) in ZnP(6)V–AgNP composite films are larger than that in ZnP(6)V films. MFEs on photon upconversion based on sensitized triplet?triplet annihilation (PUC-TTA) are examined in platinum(II) octaethylporphyrin/9,10-diphenylanthracene (DPA) systems at different DPA concentrations and laser power densities. With increasing of magnetic fields, the upconverted fluorescence intensities from DPA decreased at low DPA concentration, while those increased at high DPA concentration. Positive MFEs on PUC-TTA are observed for the first time and are most likely attributable to aggregation of DPA. The magnitudes of the MFEs at the high excitation power density become much smaller than those in low excitation power density in both low and high concentrations of DPA.