Electroluminescent devices are devices that operate on the principle of electroluminescence. Electroluminescence is the phenomenon in which a material emits light in response to the passage of an electric current (i.e. electric energy) or to a strong electric field. An electroluminescent device (EL device) includes an electroluminescent material that is configured to emit light in response to receiving electrical energy (i.e. receiving electrical current). The colour of an electroluminescent device (EL device) may be altered by adding phosphor to absorb the light emitted by the electroluminescent material and re-emit photons having a particular wavelength based on the composition of the phosphor. Electroluminescent devices may comprise a semiconductor material or a phosphor compound that emits light.

In one general configuration an EL device comprises at least one electrode layer and an electroluminescence layer attached to the electrode layer. The electrode layer is formed of an ionically conductive material and is configured to conduct electricity (i.e. electrical energy) to the electroluminescence layer. The electroluminescence layer comprises a material that illuminates when exposed to electricity i.e. electrical energy such as for example a phosphor based material or a sulphide.