The field emission properties of SnO2 nanowhiskers were observed to change after annealing under O2 and N2. The electron current increased significantly from the sample annealed in N2 and the threshold field decreased from 3.17V∕μm of the as-grown sample to 2.59V∕μm of the annealed sample. The mechanism of the field emission enhancement was explored using Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy (XPS). The results reveal that after annealing in N2, the amount of Sn–O bonds decreased and N atoms were introduced onto the surface. The binding energies of Sn 3d and O 1s determined by high resolution XPS analysis show a shift of 0.55 and 0.47eV, respectively, toward the high energy side. This shows that the electron emission enhancement arises from a decrease in the work function. The changes in the field emission effect from the sample annealed in O2 are different and a possible mechanism is also proposed.
Discussion(0)
No comments yet. Be the first to comment.