title: Light harvesting and energy transfer in multiporphyrin-modified CdSe nanoparticles.
abstract: Multiporphyrin-modified CdSe nanoparticles (CdSe-H2P) were prepared to elucidate the interaction between chromophores and luminescent semiconducting nanoparticles in the excited and ground states. The CdSe-H2P nanoparticles were obtained by place-exchange reactions of hexadecylamine-thiophenol-modified CdSe nanoparticles with porphyrin alkanethiols in toluene. The number of porphyrin molecules on the surface of a single CdSe nanoparticle increased with increasing reaction time to reach a saturated maximum of 21. The porphyrins as well as the core in CdSe-H2P can absorb UV/Vis radiation. Steady-state emission and emission-lifetime measurements reveal efficient energy transfer from the CdSe excited state to the porphyrins in the CdSe-H2P nanoparticles. The resulting porphyrin excited singlet state is not quenched by the CdSe core. These unique properties are in sharp contrast with those of multiporphyrin-modified metal and silica nanoparticles. Thus, semiconducting nanoparticle-multiporphyrin composites are highly promising as novel artificial photosynthetic materials.
authors.affiliation: Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Soonchul
authors.initials: S
authors.lastname: Kang
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yasuda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyasaka
authors.forename: Hironobu
authors.initials: H
authors.lastname: Hayashi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Umeyama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matano
authors.forename: Kaname
authors.initials: K
authors.lastname: Yoshida
authors.forename: Seiji
authors.initials: S
authors.lastname: Isoda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Imahori
mesh_terms: D000042:Absorption; D019187:Cadmium Compounds / Q000737:chemistry*; D004579:Electron Transport; D004735:Energy Transfer; D005453:Fluorescence; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D010777:Photochemistry; D011166:Porphyrins / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D012666:Semiconductors; D012993:Solar Energy; D014466:Ultraviolet Rays
chemical_list: D019187:Cadmium Compounds; D011166:Porphyrins; D018036:Selenium Compounds; C058667:cadmium selenide