title: Performance of natural-dye-sensitized solar cells by ZnO nanorod and nanowall enhanced photoelectrodes.
abstract: In this work, two natural dyes extracted from henna and mallow plants with a maximum absorbance at 665 nm were studied and used as sensitizers in the fabrication of dye-sensitized solar cells (DSSCs). Fourier transform infrared (FTIR) spectra of the extract revealed the presence of anchoring groups and coloring constituents. Two different structures were prepared by chemical bath deposition (CBD) using zinc oxide (ZnO) layers to obtain ZnO nanowall (NW) or nanorod (NR) layers employed as a thin film at the photoanode side of the DSSC. The ZnO layers were annealed at different temperatures under various gas sources. Indeed, the forming gas (FG) (N2/H295:5) was found to enhance the conductivity by a factor of 103compared to nitrogen (N2) or oxygen (O2) annealing gas. The NR width varied between 40 and 100 nm and the length from 500 to 1000 nm, depending on the growth time. The obtained NWs had a length of 850 nm. The properties of the developed ZnO NW and NR layers with different thicknesses and their effect on the photovoltaic parameters were studied. An internal coverage of the ZnO NWs was also applied by the deposition of a thin TiO2layer by reactive sputtering to improve the cell performance. The application of this layer increased the overall short circuit currentJscby seven times from 2.45 × 10-3mA/cm2to 1.70 × 10-2mA /cm2.
authors.affiliation: Laboratoire des Semi-conducteurs et Dispositifs Electroniques, LISIER, University of Tunis, Ecole Nationale Supérieure d'Ingénieurs de Tunis, 05 Av. Taha Hussein 1008 Montfleury, Tunis, Tunisia.
authors.forename: Saif
authors.initials: S
authors.lastname: Saadaoui
authors.affiliation: Laboratoire des Semi-conducteurs et Dispositifs Electroniques, LISIER, University of Tunis, Ecole Nationale Supérieure d'Ingénieurs de Tunis, 05 Av. Taha Hussein 1008 Montfleury, Tunis, Tunisia.
authors.forename: Mohamed Aziz
authors.initials: MA
authors.lastname: Ben Youssef
authors.affiliation: Laboratoire des Semi-conducteurs et Dispositifs Electroniques, LISIER, University of Tunis, Ecole Nationale Supérieure d'Ingénieurs de Tunis, 05 Av. Taha Hussein 1008 Montfleury, Tunis, Tunisia; Laboratoire de Photovoltaïque, centre de Recherche et des Technologies de l'énergie, Technopole de Borej-Cedria, BP 95, Hammam-Lif, Tunis 2050, Tunisia.
authors.forename: Moufida
authors.initials: M
authors.lastname: Ben Karoui
authors.affiliation: Laboratoire des Semi-conducteurs et Dispositifs Electroniques, LISIER, University of Tunis, Ecole Nationale Supérieure d'Ingénieurs de Tunis, 05 Av. Taha Hussein 1008 Montfleury, Tunis, Tunisia.
authors.forename: Rached
authors.initials: R
authors.lastname: Gharbi
authors.affiliation: CNR-IMM, Zona Industriale Strada VIII, N°. 5, 95121 Catania, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Smecca
authors.affiliation: MATIS CNR-IMM and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, Catania, Italy.
authors.forename: Vincenzina
authors.initials: V
authors.lastname: Strano
authors.affiliation: MATIS CNR-IMM and Dipartimento di Fisica e Astronomia, Università di Catania, via S. Sofia 64, Catania, Italy.
authors.forename: Salvo
authors.initials: S
authors.lastname: Mirabella
authors.affiliation: CNR-IMM, Zona Industriale Strada VIII, N°. 5, 95121 Catania, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Alberti
authors.affiliation: CNR-IMM, Zona Industriale Strada VIII, N°. 5, 95121 Catania, Italy.
authors.forename: Rosaria A
authors.initials: RA
authors.lastname: Puglisi
keywords: DSSCs; I–V measurement; ZnO; nanorods; nanowalls; natural dye