Who invented the first solid state diode?

Answer 1

A diode is an electronic component with two terminals that conduct asymmetrically. Although there are different types of diodes with different invention histories, the thermionic diodes were first described by Frederick Guthrie in 1873.

Answer 2

The Indian scientist Jagadish Chandra Bose invented the first solid state diode during his pioneering experiments with microwaves in 1894 and applied for a patent on it, the galena crystal cat's whisker point contact diode in 1901.

These diodes were used throughout the early days of radio as they were very inexpensive and any young boy that wanted to hear the newfangled radio transmissions could make his own at home and build what is called a crystal radio set.

Even today you can buy crystal radio sets with these diodes (the galena crystal cat's whisker diode actually permits reception of weaker stations than so called crystal radio sets built with modern junction diodes, although it requires readjustment of the cat's whisker to keep the reception good which the modern junction diode does not).

Answer 3

The principle of the silicon diode was demonstrated in 1874, just a year after the thermionic triode (a vacuum tube) and early development carried on in parallel with that of the Triode.

At this time the devices were actually referred to as rectifiers, as the term Diode was not defined until 1919, nearly 50 years later.

At this early stage of the late nineteenth century there was no real application outside of power circuits. The first radio transmission had only just been made in 1866, while the first telephone call was still 3 years away in 1876!

So audio and control applications had yet to be invented, while what signal amplification was around used mechanical or electromagnetic techniques.

The only electrical applications were those for lighting or electric motors.

In the early years of electronics, the silicon diode was not very practical.

The first 'domestic' radio receiver (a crystal set) wasn't built until 1906, and radio recievers generally weren't widespread until the 1930's.

Radio transmitters needed high power and so they used valves.

Most radio recievers needed to amplify the radio signal, so used valves and hence also required the higher voltages, giving a high cost.

So even when radio was in use the only real application for the diode was low power radio receivers, usually home made and thus very cheap.

Such home made recievers could use much lower low voltages, especially if Cat's Whisker diodes were used, while the requirement for signal amplification was minimised by the use of high impedance earpieces or headphones.

It was nearly 75 years after the diode was invented that the first Transistor Radio was available in 1952.

Answer 4

John Fleming

Answer 5

j a Fleming UK In 1704

Answer 6

Russell Ohl invented pn juction diode.

Answer 7

flemming