Organic electroluminescent devices

An organic electroluminescent device, comprising:

• a light-emitting layer,
• wherein the light-emitting layer is obtained from evaporation of a composition comprising a mixture of a first compound and a second compound, the first compound and the second compound being provided from one container;
• wherein the first compound has a different chemical structure than the second compound;
• wherein the first compound has an evaporation temperature T1 between 150° C. to 400° C. and the second compound has an evaporation temperature T2 between 150° C. and 400° C., the evaporation temperature being measured in the vacuum deposition chamber at a deposition rate of 0.08 nm/sec (0.8 Å/sec) at a constant pressure between 1×10−6 Torr to 1×10−8 Torr;
• wherein a temperature difference T1-T2 is in a range between −40° C. to 40° C.;
• and
• wherein the first compound and the second compound are each independently selected from among a host compound and a thermally activated delayed fluorescence (TADF) compound, at least one of the first compound or the second compound being the TADF compound.

A method for generating a light-emitting layer, the method comprising:

• mixing a first compound and a second compound together to form a homogeneous mixture,
• wherein the first compound has a different chemical structure than the second compound;
• wherein the first compound has an evaporation temperature T1 between 150° C. to 400° C. and the second compound has an evaporation temperature T2 between 150° C. and 400° C., the evaporation temperature being measured in the vacuum deposition chamber at a deposition rate of 0.08 nm/sec (0.8 Å/sec) at a constant pressure 1×10−6 Torr to 1×10−8 Torr;
• wherein the temperature difference T1-T2 is in a range between −40° C. to 40° C.;
• and
• wherein the first compound and second compound each are independently selected from a host compound and a thermally activated delayed fluorescence (TADF) compound, at least one of the first compound or the second compound is the TADF compound, and
• evaporating the homogeneous mixture of the first compound and the second compound together out of one container to provide a light-emitting layer, wherein further compounds are optionally co-evaporated out of one or more further containers other than the one container.

An organic electroluminescent device, comprising:

• a light-emitting layer,
• wherein the light-emitting layer comprises a composition comprising an evaporated mixture of a first compound and a second compound, the first compound and the second compound being from one container;
• wherein the first compound has a different chemical structure than the second compound;
• wherein the first compound has an evaporation temperature T1 between 150° C. to 400° C. and the second compound has an evaporation temperature T2 between 150° C. and 400° C., the evaporation temperature being measured in the vacuum deposition chamber at a deposition rate of 0.08 nm/sec (0.8 Å/sec) at a constant pressure between 1×10−6 Torr to 1×10−8 Torr;
• wherein a temperature difference T1-T2 is in a range between −40° C. to 40° C.;
• and
• wherein the first compound and the second compound are each independently selected from among a host compound and a thermally activated delayed fluorescence (TADF) compound, at least one of the first compound or the second compound being the TADF compound.