The concepts of vacuum devices and semiconductor devices

Electron devices and their structures are instruments whose operating principle is based on various electrical phenomena in a vacuum or rarefied gas. Electron devices are categorized into discharge and non-discharge devices.

In a non-discharge device, all electrical phenomena occur within the metal wires within the vacuum. An incandescent light bulb is an example of a non-discharge device.

The primary physical process within a discharge device is the passage of electric current through a vacuum or rarefied gas. Discharge devices themselves are further categorized as electronic devices and gas discharge devices.

Electronic devices utilize free electrons, obtained by various methods, that move in a certain direction in a vacuum.

In a gas discharge device, the charge carriers include not only free electrons but also ions generated by the ionization of the gas within the device.