title: Anisotropic exciton relaxation in nanostructured metal (Zn and F(16)Zn)-phthalocyanine.
abstract: We report ultrafast excited state dynamics of zinc phthalocyanine and zinc hexadecafluoro phthalocyanine thin films which have nanorod-like structures. Excitons in the singlet states undergo multi-exponential relaxation processes to the ground state and the singlet lifetime within a few tens of picoseconds is attributed to the diffusion-limited exciton annihilation process. Diffusive migration of the singlet excitons shows the anisotropic lifetimes depending on the polarization of probe beam. Similar anisotropy is observed in the X-ray diffraction data which exhibits long-range alignment of molecular columns along the long axis of nanorod, whereas disordered arrangement in lateral direction to the axis of nanorod.
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Ahn
authors.forename: Wei-Hyun
authors.initials: WH
authors.lastname: Liou
authors.forename: Huang-Ming Philip
authors.initials: HM
authors.lastname: Chen
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Hsu