What is the term for materials that emit light when electric current is passed through them?

The term that refers to materials emitting light when an electric current is passed through them is electroluminescence. This phenomenon occurs in specific types of materials, often semiconductors, which can emit light as a direct result of electrical excitation. Electroluminescent materials are commonly used in applications such as LED lighting and displays, where the flow of electric current causes them to produce visible light.

The other terms listed, while related to light emission, describe different processes. Photoluminescence involves the emission of light after the absorption of photons (light energy). Thermoluminescence refers to light emitted when a material is heated after previously storing energy from radiation. Fluorescence is the process where a substance absorbs light or other electromagnetic radiation and then re-emits it, but this process occurs almost instantaneously and requires continuous excitation.

Understanding electroluminescence is vital for applications in lineman work, as it relates to the technologies used in lighting and signaling within electrical networks.