Author/Authors :
Petra Lommens، نويسنده , , Philippe F. Smet، نويسنده , , Celso de Mello Donega، نويسنده , , Andries Meijerink، نويسنده , , Luc Piraux، نويسنده , , Sébastien Michotte، نويسنده , , Stefan M?téfi-Tempfli، نويسنده , , Dirk Poelman، نويسنده , , Zeger Hens، نويسنده ,
Abstract :
We performed photoluminescence experiments on colloidal, Co2+-doped ZnO nanocrystals in order to study the electronic properties of Co2+ in a ZnO host. Room temperature measurements showed, next to the ZnO exciton and trap emission, an additional emission related to the Co2+ dopant. The spectral position and width of this emission does not depend on particle size or Co2+ concentration. At 8 K, a series of ZnO bulk phonon replicas appear on the Co2+-emission band. We conclude that Co2+ ions are strongly localized in the ZnO host, making the formation of a Co2+ d-band unlikely. Magnetic measurements revealed a paramagnetic behaviour.
