Enhanced secondary electron emission from group III nitride/ZnO coaxial nanorod heterostructures

The process of enhancement of secondary electron emission (SEE) yields from ultrafine coaxial GaN/ZnO and nanoneedle heterostructures was analyzed. The surface morphology of ZnO nanoneedles, and of AlN/ZnO and GaN/ZnO coaxial heterostructures, was investigated by scanning electron microscopy. It was found that the SEE yields are significantly enhanced by the inherited nanostructure from the ZnO nanoneedle template. The enhancement of SEE in the coaxial heterostructures is due to the combined effect of the group III nitride layer and the nanostructured tomography. It was also found that AlN/ZnO and GaN/ZnO coaxial heterostructures have a higher SEE yield than thin films of AlN and GaN deposited on Si substrates.