Green coloration of Co-doped ZnO explained from structural refinement and bond considerations.
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.
Gaudon
M
M
Bordeaux Institute of Condensed Matter Chemistry, ICMCB-CNRS, 87 avenue du Dr Albert Schweitzer, 33608, Pessac Cedex, France. gaudon@icmcb-bordeaux.cnrs.fr
Toulemonde
O
O
Demourgues
A
A