Morphology and optical properties of Co doped ZnO textured thin films

Depending on the ZnO seed-layers, a new kind of cobalt doped zinc oxide (Zn1−xCoxO) thin films with controllable morphology were prepared by a facile solvothermal method. A series of ZnO thin films with different Co contents were applied to study the effect of doped Co on morphology, structural and optical properties. It is found that the doped content plays an important role on morphology evolution of Zn1−xCoxO films. The results of scanning electron microscope (SEM) indicate that the Zn1−xCoxO films are highly uniform and porous. Co has been successfully doped into the ZnO lattice structure and revealed by X-ray diffraction (XRD) and energy dispersive spectrum (EDS). It can be found that Zn1−xCoxO thin films possess good crystalline quality through the characterization of transmission electron microscope (TEM) and high-resolution transmission electron microscopy (HRTEM). All of the samples show a stronger violet emission and ultraviolet absorption, and the violet emission peaks shift towards red with increasing of Co content. In addition, the magnetic result demonstrates that the prepared Co-doped ZnO thin films are room-temperature ferromagnetic materials.

Graphical abstractSuch special morphology provides necessary surface roughness as well as a highly porous two-dimensional structure to our later film functionalization.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► In this work, a new kind of Zn1−xCoxO porous thin film was prepared by solvothermal method. ► The doping content plays an impotent role on morphology evolution of thin films. ► All of samples show a stronger violet emission and ultraviolet absorption. ► The prepared Zn1−xCoxO thin films are room-temperature ferromagnetic materials.