Patent ID: 9209415
Filing Date: 2015-12-08
Classification: H01L

Abstract:
1. A light-emitting device comprising: an anode; a hole-transport layer over the anode, the hole-transport layer comprising a first host material and an oxide of any of Group 4 to 8 metals; a first light-emitting layer over and in contact with the hole-transport layer; a second light-emitting layer over and in contact with the first light-emitting layer; an electron-transport layer over and in contact with the second light-emitting layer; and a cathode over the electron-transport layer, wherein among the anode and the cathode, only the cathode has a light-transmitting property so that light is extracted through the cathode, wherein the first light-emitting layer contains the first host material and a first light-emitting material, wherein the second light-emitting layer contains the first host material and a second light-emitting material, wherein a hole-transport property of the first light-emitting layer is higher than a hole-transport property of the second light-emitting layer, and wherein emission colors of the first light-emitting material and the second light-emitting material are red and yellow, respectively.