elektroluminescence

Elektroluminescence, also known as cold cathode fluorescence, is a phenomenon where light is emitted by an electrical discharge in a low-pressure gas, typically at a pressure of around 10^-3 to 10^-5 times atmospheric pressure. This occurs when a gas, such as neon or argon, is excited by an electric current and releases energy in the form of light.

The process of elektroluminescence was first discovered in the 1820s by Michael Faraday, who observed a faint glow emanating from electrodes in a low-pressure gas. The effect was later studied in more detail by British physicist John Slepian in the 1920s, who discovered that the color and spectrum of the light emitted varied depending on the gas used.

In a typical elektroluminescence setup, a low-pressure gas is contained within a sealed tube and an electric voltage is applied across a thin electrode inserted into the tube. The electric field accelerates the gas molecules, causing them to collide and excite the gas atoms or molecules, which then release energy in the form of light when they return to their ground state.

Elektroluminescence is often used in applications such as neon signs and vacuum fluorescent displays (VFDs), where it is used to produce a visible light display. The effect can also be observed in plasma TVs and other low-pressure gas discharges. While the mechanism of elektroluminescence is still not fully understood, research has shown that it is a complex interplay of atomic and molecular physics, which can be controlled and harnessed for various technological applications.