glow in the dark material Internal substances absorb energy in some way

glow in the dark material Internal substances absorb energy in some way, to convert it into light radiation (non-equilibrium radiation) is called light; in practical applications, will be excited to emit light by the external solid called luminescent material. They can form a powder, crystal, film or crystal and other uses, glowing sheets the main component is a rare earth metal compounds and semiconductor materials, very close relationship with the non-ferrous metals.
1. When a substance is excited (rays, energetic particles, electron beam, an external electric field, etc.), the substance in the excited state, the energy of the excited state will be released in the form of light or heat. If the energy of this section is the visible, ultraviolet or near infrared electromagnetic radiation, this process is called emission process.
2, light is the substance in the form of light outside of the thermal radiation emitted excess energy, this emission process has a certain duration.