ULTRA-THIN LAYER ALKALINE EARTH METALS AS STABLE ELECTRON-INJECTING CATHODES FOR POLYMER LIGHT EMITTING DIODES

摘要

This invention pertains generally to the field of light-emitting diodes, LEDs. More particularly, this invention relates to polymer LEDs which offer high brightness, high efficiency, and extended operating life, and which comprise: a transparent hole-injecting anode layer (11); an emissive layer comprising an electroluminescent polymer (12); and an electron-injecting cathode layer (13); the cathode layer comprises an ultra-thin layer of alkaline earth metal, such as calcium, strontium, and barium, having a thickness of about 100 Angstroms or less, typically from about 15 to about 100 Angstroms.