Organic electroluminescent device

An organic electroluminescent device, comprising:

• an anode, a cathode and an organic layer disposed between the anode and the cathode;
• wherein the organic layer comprises a first organic layer containing a first organic material and a second organic material, wherein the lowest unoccupied molecular orbital (LUMO) energy level of the first organic material is denoted as LUMOfirst_organic_material, the highest occupied molecular orbital (HOMO) energy level of the second organic material is denoted as HOMOsecond_organic_material, and LUMOfirst_organic_material−HOMOsecond_organic_material≥0.3 eV;
• the first organic layer has a conductivity greater than or equal to 3×10−5 S/m;
• and the second organic material has a structure represented by Formula H:
• wherein in Formula H,
• Ar1, Ar2 and Ar3 are, at each occurrence identically or differently, selected from substituted or unsubstituted aryl having 6 to 30 carbon atoms or substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms;
• when Ar1, Ar2 and Ar3 are, at each occurrence identically or differently, selected from substituted aryl having 6 to 30 carbon atoms or substituted heteroaryl having 3 to 30 carbon atoms, the aryl or heteroaryl is substituted with one or more groups selected from the group consisting of:
• deuterium, halogen, unsubstituted alkyl having 1 to 20 carbon atoms, unsubstituted cycloalkyl having 3 to 20 ring carbon atoms, unsubstituted heteroalkyl having 1 to 20 carbon atoms, an unsubstituted heterocyclic group having 3 to 20 ring atoms, unsubstituted arylalkyl having 7 to 30 carbon atoms, unsubstituted alkoxy having 1 to 20 carbon atoms, unsubstituted aryloxy having 6 to 30 carbon atoms, unsubstituted alkenyl having 2 to 20 carbon atoms, unsubstituted alkynyl having 2 to 20 carbon atoms, unsubstituted aryl having 6 to 30 carbon atoms, unsubstituted heteroaryl having 3 to 30 carbon atoms, unsubstituted alkylsilyl having 3 to 20 carbon atoms, unsubstituted arylsilyl having 6 to 20 carbon atoms, unsubstituted alkylgermanyl having 3 to 20 carbon atoms, unsubstituted arylgermanyl having 6 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a cyano group, an isocyano group, a hydroxyl group, a sulfanyl group, a sulfinyl group, a sulfonyl group, a phosphino group and combinations thereof;
• and
• adjacent substituents Ar1, Ar2 and Ar3 can be optionally joined to form a ring.

A first organic electroluminescent device, comprising:

• an anode, a cathode and an organic layer disposed between the anode and the cathode;
• wherein the organic layer comprises a first organic layer being in direct contact with the anode and containing a first organic material and a second organic material;
• the first organic layer has a conductivity greater than or equal to 3×10−5 S/m;
• an efficiency-to-voltage ratioη of the first organic electroluminescent device is greater than or equal to 104% of an efficiency-to-voltage ratio η of a second organic electroluminescent device at the same current density;
• wherein η=EQE/(voltage×) and denotes a proportion of excitons allowed to be emitted in quantum mechanics;
• the second organic electroluminescent device has the same device structure as the first organic electroluminescent device except that:
• the organic layer that is in direct contact with the anode in the second organic electroluminescent device is a third organic layer containing a third organic material and a fourth organic material, and materials in at least one of the following two groups are the same:
• group (i):
• the first organic material and the third organic material, and group (ii):
• the second organic material and the fourth organic material;
• and
• the third organic layer in the second organic electroluminescent device at least satisfies one of the following requirements:
• (1) the highest occupied molecular orbital (HOMO) energy level of the fourth organic material is denoted as HOMOfourth_organic_material,and HOMOfourth_organic_material>−5.1 eV;
• (2) the lowest unoccupied molecular orbital (LUMO) energy level of the third organic material is denoted as LUMOthird_organic_material, the HOMO energy level of the fourth organic material is denoted as HOMOfourth_organic_material, and LUMOthird_organic_material−HOMOfourth_organic_material<0.3 eV;
• (3) the third organic layer has a conductivity of less than 3×10−5 S/m.