tunnel diode

electronics

Also known as: Esaki diode

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July 14, 2026

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A tunnel diode is a semiconductor device featuring a single p-n junction where both sides are heavily doped with impurities. This heavy doping results in a very narrow depletion layer, allowing electrons to "tunnel" directly through the junction under forward bias. This unique characteristic creates a negative resistance effect, where current decreases as voltage increases.1

Due to its rapid tunneling time and low noise, the tunnel diode is employed in specialized, low-power microwave applications. These include use as a local oscillator and in frequency-locking circuits. The device is capable of extremely fast transformations between its two stable states and can be used for amplifying, switching, and computer information storage.12

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Leo Esaki
…which became known as the Esaki diode. It also opened new possibilities for solid-state developments that his corecipients of the 1973 prize exploited separately. In 1960 Esaki was awarded an IBM (International Business Machines) fellowship for further research in the United States, and he subsequently joined IBM’s research laboratories in…
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…which became known as the Esaki diode. It also opened new possibilities for solid-state developments that his corecipients of the 1973 prize exploited separately. In 1960 Esaki was awarded an IBM (International Business Machines) fellowship for further research in the United States, and he subsequently joined IBM’s research laboratories in…
Read More

semiconductor device
Tunnel diode
A tunnel diode consists of a single p-n junction in which both the p and n sides are heavily doped with impurities. The depletion layer is very narrow (about 100 angstroms). Under forward biases, the electrons can tunnel or pass directly through the…
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A tunnel diode consists of a single p-n junction in which both the p and n sides are heavily doped with impurities. The depletion layer is very narrow (about 100 angstroms). Under forward biases, the electrons can tunnel or pass directly through the…
Read More