Presentation Information
[22p-P01-3]Photo-excited carrier dynamics of zinc phthalocyanine thin films studied by time-resolved photoemission spectroscopy
〇Isamu Yamamoto1, Junpei Azuma1, Masaki Imamura1, Kazutoshi Takahashi1 (1.Saga Univ.)
Keywords:
Time-resolved photoemission spectroscopy,photo-excited carrier dynamics,phthalocyanine
We investigated the photo-excited carrier dynamics of zinc phthalocyanine (ZnPc) thin films grown on highly oriented pyrolytic graphite (HOPG) using time-resolved photoemission spectroscopy (TRPES). In the TRPES spectrum at the delay time of 0 ps, three peaks (Lx, L0, L1) originating from excited states of ZnPc molecules were observed. The lifetimes of L0 and L1 are independent of deposition amount and are in good agreement with those of intramolecular vibrational relaxation. The Lx intensity of the 19-nm-thick film persisted more than 10 ps, while the transient population in the monolayer film disappeared within 400 fs. The relaxation timescale for the 19-nm-thick film is consistent with those of intersystem crossing. Thus, the Lx peak originates from the bottom of the S1 state. Despite the bottom of the S1 manifold, the Lx transient population in the monolayer film exhibits fast relaxation, suggesting electron transfer from ZnPc to HOPG.