|Dr. Leo Esaki, inventor
of the Tunel diode. (Electronic World)
Its feasibility had been predicted in 1929 by George Gamow -the American
physicist who started the studies to explain the large Neutrino emissions
due to thermonuclears explosions in solar nucleous - It was so named
because its operation relied on the quantum-mechanical probability
of electrons tunneling through an energy barrier they could not surmount.
Therefore, it was only in 1958 through the researches of the Japanese
scientist Dr Leo Esaki, working for Sony Corporation, that the first
Tunnel diode could be developed in a practical way. Fig 255
| Close up of the device
invented by Dr. Esaki as known as tunel diode.
Originally, an extremely abrupt junction between very highly doped
P and N regions of a Gemanium matrix, to make the depletion regions
of the diode very thin, on the order of a few hundreds of Angstrons,
formed such semiconductor device.
In effect due to its behavior to a negative resitance, the Tunnel
diode could be put to use for high-frequency amplification, oscillation
Due to its high speed in signal processing, around 100 picoseconds,
manufactures foresaw many applications for such a kind of device.
Therefore the interest in the tunnel diode waned rapidly due to the
improvement in the Transistor technology as well as the birth of the
integrated circuit, which was the fundamental element for the manufacturing
of computer memory, originally the purpose of the device invented
by Dr. Esaki.
Gaining in importance throughout the late fifities and early sixties
were semiconductor devices whose operation extended to the uppermost
frequency and beyond to the visible-light spectrum. Most of these
emerged from compound semiconductors such as Gallium Arsenide and
Indium Phosphide, which led to the invention of light emitting diode