Organic electroluminescence devices and displays

Electroluminescence color display screen having matrix picture elements, the display screen comprising a multi-layer structure disposed on opposite sides of an insulating, optically at least translucent base layer, the layer structure comprising:

• a) on a first side of the base layer:
• a conductive, optically at least translucent base electrode layer abutting the first side and patterned into a plurality of electrically mutually isolated longitudinal stripes extending in a first direction;
• an at least partially light-reflective top electrode layer arranged on the base electrode layer and patterned into a plurality of electrically mutually isolated longitudinal stripes extending in a second direction which is different from the first direction;
• and
• a first organic electroluminescence layer disposed between the base electrode layer and the top electrode layer and capable of emitting optical radiation in a wavelength range characterized by a first electroluminescence wavelength;
• and
• b) on a second side of the base layer:
• a spectrally selective reflector;
• and
• at least one color conversion layer arranged between the second side of the base layer and the spectrally selective reflector,
• wherein the at least one color conversion layer produces a light emission in a wavelength range characterized by at least one other wavelength different from the first electroluminescence wavelength upon excitation by the first electroluminescence wavelength, and
• wherein the spectrally selective reflector reflects light at the first electroluminescence wavelength and transmits light at the other wavelength for spectrally filtering the transmitted light at the first wavelength and improving the color conversion efficiency of the color display screen at the other wavelength.