摘要 |
<p>An edge emitter (110) has a cap (112) on top of a thin-film stack including a top transparent electrode (114), a bottom electrode (122), an active film (118) between the two electrodes and an insulating film (120) between the active film and the bottom electrode. Both the refractive indexes of the cap and the top transparent electrode are substantially matched to that of the active film to increase the amount of electroluminescent radiation propagating from the active film into the cap. The cap is thicker than the active film, and is made of a material with an attenuation to the electroluminescent radiation that is lower than that of the active film material. One side surface, the emitting side surface (132), of the cap is more transmissive to the electroluminescent radiation than the other side surfaces and the top surface of the cap. A significant portion of the electroluminescent radiation from the active film entering the cap is redirected towards the emitting side surface to be radiated from the edge emitter. The emitting side surface (132) can be tilted and the thickness of the insulating layer (120) can be controlled to be within a predetermined range to increase the efficiency of the edge emitter.</p> |