Organic light-emitting diode with high color rendering

An organic light-emitting diode, which comprises:

• a substrate with a first electrode formed thereon;
• a first light-emitting region disposed over the first electrode, wherein the first light-emitting region comprises at least one layer of a first light-emitting layer, the at least one first light-emitting layer comprises at least one first dye, and the first dye is a fluorescent dye, a phosphorescence dye, or a mixture thereof;
• a spacer disposed on the first light-emitting region;
• a second light-emitting region disposed on the spacer, wherein the second light-emitting region comprises at least one layer of a second light-emitting layer, the at least one second light-emitting layer comprises at least one second dye, and the second dye comprises Ir(piq)2(acac), Ir(2-phq)3, and Ir(ppy)3, and the second light-emitting layer further comprises a host material, in which a content of the Ir(piq)2(acac) is 0.01 to 10 wt % of the host material, a content of the Ir(2-phq)3 is 0.01 to 10 wt % of the host material, and a content of the Ir(ppy)3 is 0.01 to 10 wt % of the host material;
• and
• a second electrode disposed over the second light-emitting region,
• wherein the spacer is made of a material with a HOMO and LUMO energy levels between those of the first light-emitting region and the second light-emitting region respectively.