A self-consistent quantum model is developed to investigate the structural enhancement mechanism of field emission ͑FE͒ from multilayer semiconductor films. Compared with previous two-step FE mechanism, our self-consistent model is straightforward to understanding the whole tunneling process of the FE from multilayer semiconductor films. Calculated results show that FE characteristics can be remarkably improved only by structure modulation. The distinct structure effect of the FE characteristics mainly result from two reasons: one is the energy level shift and the other is effective surface barrier reduction due to accumulation of electrons in the occupied states. The present study offered new insights in structural effects for field emitters, which opened the possibility of carrying field emission research and application from an alternative approach.

A theoretical model based on the band bending theory was developed for explaining the field-emission mechanism of wide-band gap semiconductors (WBGSs). It was shown that the maximum value of the band bending, which is nearly linearly proportional to the band gap of WBGSs, may amount to a few eV. Furthermore, the calculated field-emission energy distribution combined with the band bending analyzed on cubic boron nitride (c-BN) as typical one of WBGSs, indicated that the electron emission originates from the conduction band minimum resulting from the band bending. These results present a perspective to explain the field-emission mechanism, in which it is considered that the band bending, as well as the negative electron affinity, is of equal importance to the excellent field emission performances of WBGSs.