So increased voltage results in a drop in current. As the voltage continues to increase the junction begins to function as a normal diode as electrons travel by conduction through the p-n junction and no longer tunnel through it. Therefore the most important region for operation in a tunnel diode is the negative resistance area.

Used in reverse direction Esaki diodes are called back diodes and act as very fast rectifiers with a zero offset with extreme linearity for power signals and have an accurate square law characteristic in the reverse direction. As back diodes, with reverse bias at high reverse voltage, electrons actually flow in the opposite direction, as electron states on each side of the p-n junction become increasingly aligned, allowing electrons to tunnel through the p-n junction going the opposite direction -- this is called the Zener effect which also occurs in zener diodes.

Above is a...
[ View Full Essay]