Electricity, history electron research

The electrical parameters, especially the conductivity, were investigated early in history of ZnO research. An overwiew over electronic properties of ZnO up to the end of the 1950s was given by Heiland et al. in 1959 [7]. Most of the early investigations up to about 1955 were performed on sintered polycrystalline ZnO samples [4,8], which suffered from the general problem of conduction in porous, inhomogeneous materials with a lower density compared with... 

Modem electronic devices build on a long history of invention, discovery, and basic scientific research. The most critical devices are the control circuit elements — the diode and the switching devices. The latter began as triode vacuum tubes and are now generally transistors. Diodes pass current easily in only one direction. The original diode was invented in 1905 by J. Ambrose Flemming based on observations made in the laboratories of Edison Electric. This diode vacuum tube contained a hot filament, which emits electrons, and a metallic plate collector. Electrons flow only from filament to collector. The following year Lee DeForest created the triode vacuum tube and the electronic revolution was launched. 

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