Phosphorescent OLEDs with exciton blocking layer

An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

• a phosphorescent compound of Ir or Pt represented by the formula:
• wherein;
• A is a substituted or unsubstituted heterocyclic ring containing at least one N atom;
• B is a substituted or unsubstituted aromatic or heteroaromatic ring or a ring containing a vinyl C bonded to M;
• X-Y is an anionic bidentate ligand;
• and
• either m is an integer from 1 to 3, and n in an integer from 0 to 2 such that m+n =3 for M=Ir or m is an integer from 1 to 2 and n in an integer from 0 to 1 such that m+n=2 for M=Pt;
• with at least one hole transporting co-host and at least one electron transporting co-host wherein the hole transporting co-host is a substituted triarylamine with two or more triarylamine groups and no aromatic hydrocarbon fused-rings and is present at a concentration of 5 to 70 weight % of the total of the hole- and electron transporting co-host materials in the light emitting layer and wherein the triplet energy of each of the co-host materials is greater than the triplet energy of the phosphorescent emitter;
• and wherein the electron transporting co-host is represented by the formula:
• wherein:
• Ar1 to Ar3 are independently an aromatic hydrocarbocyclic group or an aromatic heterocyclic group which may have a substituent;
• and
• an exciton blocking layer adjacent the emitting layer on the anode side comprising a hole transporting material with triplet energy greater or equal to 2.5 eV;
• and
• a layer directly adjacent the light emitting layer on the cathode side comprising an electron transporting material with triplet energy greater than the phosphorescent emitter.

An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

• a phosphorescent compound of Ir or Pt represented by the formula:
• wherein:
• A is a substituted or unsubstituted heterocyclic ring containing at least one N atom;
• B is a substituted or unsubstituted aromatic or heteroaromatic ring or a ring containing a vinyl C bonded to M;
• X-Y is an anionic bidentate ligand;
• and
• either m is an integer from 1 to 3, and n in an integer from 0 to 2 such that m+n =3 for M=Ir or m is an integer from 1 to 2 and n in an integer from 0 to 1 such that m+n=2 for M=Pt;
• with at least one hole transporting co-host and at least one electron transporting co-host wherein the hole transporting co-host is a substituted triarylamine with two or more triarylamine groups and no aromatic hydrocarbon fused-rings and is present at a concentration of 5 to 70 weight % of the total of the hole- and electron transporting co-host materials in the light emitting layer and wherein the triplet energy of each of the co-host materials is greater than the triplet energy of the phosphorescent emitter;
• and wherein the electron transporting co-host is a substituted 1,3,4-oxadiazole;
• and
• an exciton blocking layer adjacent the emitting layer on the anode side comprising a hole transporting material with triplet energy greater or equal to 2.5 eV;
• and
• a layer directly adjacent the light emitting layer on the cathode side comprising an electron transporting material with triplet energy greater than the phosphorescent emitter.

An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

• a phosphorescent compound of Ir or Pt represented b the formula:
• wherein:
• A is a substituted or unsubstituted heterocyclic ring containing at least one N atom;
• B is a substituted or unsubstituted aromatic or heteroaromatic ring or a ring containing a vinyl C bonded to M;
• X-Y is an anionic bidentate ligand;
• and
• either m is an integer from 1 to 3, and n in an integer from 0 to 2 such that m+n =3 for M=Ir or m is an integer from 1 to 2 and n in an integer from 0 to 1 such that m+n=2 for M=Pt;
• with at least one hole transporting co-host and at least one electron transporting co-host wherein the hole transporting co-host is a substituted triarylamine with two or more triarylamine groups and no aromatic hydrocarbon fused-rings and is present at a concentration of 5 to 70 weight % of the total of the hole- and electron transporting co-host materials in the light emitting layer and wherein the triplet energy of each of the co-host materials is greater than the triplet energy of the phosphorescent emitter;
• and wherein the electron transporting co-host is a substituted 1,2,4-oxadiazole;
• and
• an exciton blocking layer adjacent the emitting layer on the anode side comprising a hole transporting material with triplet energy greater or equal to 2.5 eV;
• and
• a layer directly adjacent the light emitting layer on the cathode side comprising an electron transporting material with triplet energy greater than the phosphorescent emitter.

An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising:

• a phosphorescent compound of Ir or Pt represented by the formula:
• wherein:
• A is a substituted or unsubstituted heterocyclic ring containing at least one N atom;
• B is a substituted or unsubstituted aromatic or heteroaromatic ring or a ring containing a vinyl C bonded to M;
• X-Y is an anionic bidentate ligand;
• and
• either m is an integer from 1 to 3, and n in an integer from 0 to 2 such that m+n =3 for M=Ir or m is an integer from 1 to 2 and n in an integer from 0 to 1 such that m+n=2 for M=Pt;
• with at least one hole transporting co-host and at least one electron transporting co-host wherein the hole transporting co-host is a substituted triarylamine with two or more triarylamine groups and no aromatic hydrocarbon fused-rings and is present at a concentration of 5 to 70 weight % of the total of the hole- and electron transporting co-host materials in the light emitting layer and wherein the triplet energy of each of the co-host materials is greater than the triplet energy of the phosphorescent emitter;
• and wherein the electron transporting co-host is a substituted 1,3,5-oxadiazole;
• and
• an exciton blocking layer adjacent the emitting layer on the anode side comprising a hole transporting material with triplet energy greater or equal to 2.5 eV;
• and
• a layer directly adjacent the light emitting layer on the cathode side comprising an electron transporting material with triplet energy greater than the phosphorescent emitter.

An OLED device comprising a cathode, an anode, and located therebetween a light emitting layer (LEL) comprising a phosphorescent compound of Ir or Pt represented by the formula:

• wherein:
• A is a substituted or unsubstituted heterocyclic ring containing at least one N atom;
• B is a phenyl ring additionally substituted with one or two F atoms, one or two CF3 groups, or one F atom and one CF3 group or ring B is a phenyl ring additionally substituted with substituted or unsubstituted phenyl or napthyl group para to the M-C bond;
• X-Y is an anionic bidentate ligand;
• and
• either m is an integer from 1 to 3, and n in an integer from 0 to 2 such that m+n =3 for M=Ir or m is an integer from 1 to 2 and n in an integer from 0 to 1 such that m+n=2 for M=Pt;
• with at least one hole transporting co-host and at least one electron transporting co-host wherein the hole transporting co-host is a substituted triarylamine with two or more triarylamine groups and no aromatic hydrocarbon fused-rings and is present at a concentration of 5 to 70 weight % of the total of the hole- and electron transporting co-host materials in the light emitting layer and wherein the triplet energy of each of the co-host materials is greater than the triplet energy of the phosphorescent emitter;
• an exciton blocking layer adjacent the emitting layer on the anode side comprising a hole transporting material with triplet energy greater or equal to 2.5 eV;
• and
• a layer directly adjacent the light emitting layer on the cathode side comprising an electron transporting material with triplet energy greater than the phosphorescent emitter.