title: Identification of different pathways of electron injection in dye-sensitised solar cells of electrodeposited ZnO using an indoline sensitiser.
abstract: Charge transfer dynamics in fully operational dye sensitised solar cells consisting of an electrolyte or organic spiroOMeTAD in contact with a highly porous electrodeposited ZnO film sensitised with a monolayer of the indoline dye DN216 were observed using ultrafast transient absorption spectroscopy. From the temporal evolution of spectral signatures assigned with the help of spectroelectrochemical experiments to the population and depopulation of initial, transient and final states, a model was completed for the multistep injection of photoexcited electrons from the molecular absorber to the ZnO acceptor. Injection was found to occur via three different paths with three characteristic rates: directly from the dye's lowest unoccupied molecular orbital into the ZnO conduction band (200 fs) and via intermediate molecular dominated and surface dominated hybrid states (2 ps and 10 ps, respectively).
authors.affiliation: Laser Research Institute, Stellenbosch University, Stellenbosch, South Africa. heso@sun.ac.za.
authors.forename: Iulia
authors.initials: I
authors.lastname: Minda
authors.affiliation: Laser Research Institute, Stellenbosch University, Stellenbosch, South Africa. heso@sun.ac.za.
authors.forename: Essraa
authors.initials: E
authors.lastname: Ahmed
authors.affiliation: Laser Research Institute, Stellenbosch University, Stellenbosch, South Africa. heso@sun.ac.za.
authors.forename: Vivien
authors.initials: V
authors.lastname: Sleziona
authors.affiliation: Institut für Angewandte Physik, Justus-Liebig-Universität, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Richter
authors.affiliation: Institut für Angewandte Physik, Justus-Liebig-Universität, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
authors.forename: Max
authors.initials: M
authors.lastname: Beu
authors.affiliation: Institut für Angewandte Physik, Justus-Liebig-Universität, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
authors.forename: Jane
authors.initials: J
authors.lastname: Falgenhauer
authors.affiliation: Chemicrea Co., Ltd., 2-1-6 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Miura
authors.affiliation: Institut für Angewandte Physik, Justus-Liebig-Universität, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
authors.forename: Derck
authors.initials: D
authors.lastname: Schlettwein
authors.affiliation: Laser Research Institute, Stellenbosch University, Stellenbosch, South Africa. heso@sun.ac.za.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Schwoerer