title: Active and passive control of zinc phthalocyanine photodynamics.
abstract: In this work we report on the ultrafast photodynamics of the photosensitizer zinc phthalocyanine (ZnPc) and manipulation thereof. Two approaches are followed: active control via pulse shaping and passive control via strategic manipulation in the periphery of the molecular structure. The objective of both of these control experiments is the same: to enhance the yield of the functional pathway and to minimize loss channels. The aim of the active control experiments is to increase the intersystem crossing yield in ZnPc, which is important for application in photodynamic therapy (PDT). Pulse shaping allowed an improvement in triplet to singlet ratio of 15% as compared to a transform-limited pulse. This effect is ascribed to a control mechanism that utilizes multiphoton pathways to higher-lying states from where intersystem crossing is more likely to occur. The passive control experiments are performed on ZnPc derivatives deposited onto TiO2, serving as a model system of a dye-sensitized solar cell (DSSC). Modification of the anchoring ligand of the molecular structure resulted in an increased rate for electron injection into TiO2 and slower back electron transfer, improving the DSSC efficiency.
authors.affiliation: Optical Sciences Group, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands. d.sharma@utwente.nl
authors.forename: Divya
authors.initials: D
authors.lastname: Sharma
authors.forename: Annemarie
authors.initials: A
authors.lastname: Huijser
authors.forename: Janne
authors.initials: J
authors.lastname: Savolainen
authors.forename: Gerwin
authors.initials: G
authors.lastname: Steen
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Herek
mesh_terms: D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D056004:Molecular Dynamics Simulation; D009942:Organometallic Compounds / Q000737:chemistry*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry*; D017967:Zinc Compounds
chemical_list: D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine