Band bending mechanism for field emission in wide-band gap semiconductors

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.