COLOUR CHANGING MEDIA FOR LIGHT EMITTING DISPLAY DEVICES

摘要

The present invention relates to electroluminescent elements comprising an organic or inorganic electroluminescent material part which emits a blue light and at least one fluorescent material part which absorbs said blue light and emits a fluorescence in a visible light range from bluish green to red light said fluorescent material part exists outside of the electroluminescent material part and comprises a diketopyrrolopyrrole compound.