title: Ni Mg Mixed Metal Oxides for p-Type Dye-Sensitized Solar Cells.
abstract: Mg Ni mixed metal oxide photocathodes have been prepared by a mixed NiCl2/MgCl2 sol-gel process. The MgO/NiO electrodes have been extensively characterized using physical and electrochemical methods. Dye-sensitized solar cells have been prepared from these films, and the higher concentrations of MgO improved the photovoltage of these devices; however, there was a notable drop in photocurrent with increasing Mg(2+). Charge extraction and XPS experiments revealed that the cause of this was a positive shift in the energy of the valence band, which decreased the driving force for electron transfer from the NiO film to the dye and, therefore, the photocurrent. In addition, increasing concentrations of MgO increases the volume of pores between 0.500 and 0.050 μm, while reducing pore volumes in the mesopore range (less than 0.050 μm) and lowering BET surface area from approximately 41 down to 30 m(2) g(-1). A MgO concentration of 5% was found to strike a balance between the increased photovoltage and decreased photocurrent, possessing a BET surface area of 35 m(2) g(-1) and a large pore volume in both the meso- and macropore range, which lead to a higher overall power conversion efficiency than NiO alone.
authors.affiliation: School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.|Chemistry Unit, School of Science and Technology, University of Camerino (MC) , Via Sant'Agostino 1, 62032 Camerino, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Zannotti
authors.affiliation: School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.|School of Chemistry, Newcastle University , Newcastle upon Tyne, NE1 7RU, U.K.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Wood
authors.affiliation: School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.|School of Chemistry, Newcastle University , Newcastle upon Tyne, NE1 7RU, U.K.
authors.forename: Gareth H
authors.initials: GH
authors.lastname: Summers
authors.affiliation: Division of Materials, Mechanics and Structures, Faculty of Engineering, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Stevens
authors.affiliation: Division of Materials, Mechanics and Structures, Faculty of Engineering, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Hall
authors.affiliation: Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.
authors.forename: Colin E
authors.initials: CE
authors.lastname: Snape
authors.forename: Rita
authors.initials: R
authors.lastname: Giovannetti
authors.affiliation: Chemistry Unit, School of Science and Technology, University of Camerino (MC) , Via Sant'Agostino 1, 62032 Camerino, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Giovanetti
authors.affiliation: School of Chemistry, University of Nottingham , University Park, Nottingham, NG7 2RD, U.K.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Gibson
keywords: artificial photosynthesis; dye-sensitized solar cells; nickel oxide; p-type; photocathode