A light emitting diode, comprising: - an anode; - a light emitting layer coupled to the anode, the light emitting layer including a phosphorescent organic material and is co-doped with an organic matching material having a highest occupied molecular orbital level (HOMO) similar to a HOMO level of the phosphorescent organic material and/or with an organic matching material having a lowest unoccupied molecular orbital level (LUMO) similar to a LUMO level or a triplet energy level of the phosphorescent organic material; - a cathode coupled to the light emitting layer; and - a first interfacial layer is disposed between the light emitting layer and the anode, the interfacial layer having a thickness of 5 nm or less, and the first interfacial layer includes two or more matching materials containing an organic material that facilitates injection of holes into the light emitting layer, wherein the first of the matching materials has a HOMO level similar to a HOMO level of the phosphorescent organic material and a second of the matching materials has a HOMO level between the HOMO level of the phosphorescent organic material and the work function of the anode and the matching materials of the first interfacial layer and the light emitting layer are different; - a second interfacial layer is disposed between the light emitting layer and the cathode, the second interfacial layer having a thickness of 5 nm or less, and the second interfacial layer, includes two or more matching materials containing an organic material that facilitates injection of electrons into the light emitting layer, wherein the first of the matching materials has a LUMO level similar to the LUMO level or about equal to a triplet energy level of the phosphorescent organic material and a second of the matching materials has a LUMO level between the LUMO or the triplet energy level of the phosphorescent organic material and the work function of the cathode and the matching materials of the second interfacial layer and the light emitting layer are different; - wherein materials having similar energy levels refer to materials with energy levels within 0.3 eV of one another. - an anode; - a light emitting layer coupled to the anode, the light emitting layer including a phosphorescent organic material and is co-doped with an organic matching material having a highest occupied molecular orbital level (HOMO) similar to a HOMO level of the phosphorescent organic material and/or with an organic matching material having a lowest unoccupied molecular orbital level (LUMO) similar to a LUMO level or a triplet energy level of the phosphorescent organic material; - a cathode coupled to the light emitting layer; and - a first interfacial layer is disposed between the light emitting layer and the anode, the interfacial layer having a thickness of 5 nm or less, and the first interfacial layer includes two or more matching materials containing an organic material that facilitates injection of holes into the light emitting layer, wherein the first of the matching materials has a HOMO level similar to a HOMO level of the phosphorescent organic material and a second of the matching materials has a HOMO level between the HOMO level of the phosphorescent organic material and the work function of the anode and the matching materials of the first interfacial layer and the light emitting layer are different; - a second interfacial layer is disposed between the light emitting layer and the cathode, the second interfacial layer having a thickness of 5 nm or less, and the second interfacial layer, includes two or more matching materials containing an organic material that facilitates injection of electrons into the light emitting layer, wherein the first of the matching materials has a LUMO level similar to the LUMO level or about equal to a triplet energy level of the phosphorescent organic material and a second of the matching materials has a LUMO level between the LUMO or the triplet energy level of the phosphorescent organic material and the work function of the cathode and the matching materials of the second interfacial layer and the light emitting layer are different; - wherein materials having similar energy levels refer to materials with energy levels within 0.3 eV of one another.