title: Green coloration of Co-doped ZnO explained from structural refinement and bond considerations.
abstract: ZnO doped with Co2+ has been prepared by a Pechini process and investigated in terms of crystallographic structure and UV-visible properties. We emphasize for the first time a splitting of the ZnO band gap in two "sub-band gaps" (never clearly mentioned until now) which is fully interpreted basing on the iono-covalent nature of the O-Zn bonds. An anticipative approach of the potential structure relaxations was discussed from exchanged effective charge per bond calculated with the purely ionic Brown and Altermatt model.
authors.affiliation: Bordeaux Institute of Condensed Matter Chemistry, ICMCB-CNRS, 87 avenue du Dr Albert Schweitzer, 33608, Pessac Cedex, France. gaudon@icmcb-bordeaux.cnrs.fr
authors.forename: M
authors.initials: M
authors.lastname: Gaudon
authors.forename: O
authors.initials: O
authors.lastname: Toulemonde
authors.forename: A
authors.initials: A
authors.lastname: Demourgues