The disclosed technology generally relates to a switching device and more particularly to a switching device based on an active portion capable of switching from an insulating state to a conductive state. In an aspect, a switching device comprises an active portion interposed between two electrodes and capable of switching from an insulating state to a conducting state when a voltage higher than a threshold value is applied between the two electrodes. The threshold value is lowered by a dielectric permittivity distribution which produces a concentration of electrical field at a location within the active portion. Thus, the switching device may be devoid of a third control electrode.