Properties of a field emitter of nanometric radius deduced from curvature of F-N plot

The slope of Fowler-Nordheim (F-N) plot is not constant but increases slightly in magnitude as the anode-cathode voltage V_a is reduced. Theory for emission from a spherical surface shows that this curvature of slope increases with the curvature of the emitting surface. Through detailed calculation using the change of F-N slope, the radius of curvature of the emitting region, surface field, effective solid angle of emission and electron supply factor can be deduced.