Patent ID: 9123908
Filing Date: 2015-09-01
Classification: H01L

Abstract:
1. A light-emitting device comprising a first electrode, a second electrode, and a light-emitting active material contacting and separating the first and second electrodes, said active material comprising: a combination of a conjugated polymer and an electrolyte, said electrolyte comprising ions, allowing for electrochemical doping of the conjugated polymer, wherein a ratio between the ions and the conjugated polymer is selected to allow for the formation of: (i) a doped region at the respective electrode interface, which allows for injection and transport of electronic charge carriers into and through the doped regions, respectively, at zero or low overpotential, and (ii) an effectively undoped region, separating the doped regions, wherein injected electronic charge carriers are recombineable under excitation of the conjugated polymer and tile polymer is de-excitable under emission of light, wherein the ratio of the ions to the conjugated polymer is low enough, which corresponds to a surplus of conjugated polymer repeat units with respect to the number of ions, for the undoped region to remain effectively undoped and free from said ions, as substantially all ions in the active material are locked up in the doped regions.