Detour trajectory of field electrons from the triple junction

We have theoretically investigated the field emission from the metal-dielectric-vacuum junction. To understand the observed enhanced field emission, we have made attempts to describe both the enhancement of the electric field and the trajectory of field electrons. According to the recent studies, the field enhancement is found to be due to the combined effect of the surface charge of metal and the polarization of dielectric. The angle ratio of dielectric to vacuum is found to be the key factor in determining whether the field enhances or reduces.