Steep nonlinearity of the the forward-biased current-voltage characteristic of a system with a double-barrier resonant-tunneling structure built intoa Schottky barrier

A contact between a metal and an n-type semiconductor with a double-barrier resonant-tunneling structure built into the space-charge region is investi gated. Besides the well-known effect in which the current falls sharply, th ere is an additional possibilty: in this system there can also be a steep n onlinearity of the current-voltage (I-V) characteristic, specifically, an e ffect wherein the current increases precipitously. It is shown that the dif ferential slope of the forward branch of the I-V characteristic can be cons iderably greater than e/kT - by more than an order of magnitude at optimum values of the parameters of the problem. The dependence of the I-V characte ristic on the parameters of the structure is analyzed. (C) 2000 American In stitute of Physics. [S1063-777X(00)01111-7].