Organic light-emitting diodes with fluorescent and phosphorescent emitters

1. A light emitting device comprising:

a first electrode;

a hole transporting layer in contact with the first electrode;

a second electrode;

an electron transporting layer in contact with the second electrode; and

an emissive layer between the hole transporting layer and the electron transporting layer, the emissive layer comprising: a phosphorescent emitter, a fluorescent emitter, and a host;

wherein the emissive layer comprises:

n emitter layers comprising the host and the fluorescent emitter, and

m donor layers comprising the host and the phosphorescent emitter,

wherein n and m are integers≥2,

wherein the emitter layers do not comprise the phosphorescent emitter;

wherein the donor layers do not comprise the fluorescent emitter;

wherein the phosphorescent emitter is capable of harvesting electrogenerated excitons and transferring energy to the fluorescent emitter; and

wherein the phosphorescent emitter comprises a compound of General Formula I:

wherein:

M is Pt, Pd, Ir, Rh, or Au;

each of R 1 and R 2 is independently hydrogen, halogen, hydroxyl, nitro, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, amino, alkoxy, haloalkyl, arylalkyl, or arylalkenyl;

each of Y 1a , Y 1b , and Y 1c is independently O, NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(O)R 3 , or SiR 3 R 4 , wherein each of R 3 and R 4 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, amino, alkoxy, haloalkyl, arylalkyl, arylalkenyl, or R 3 and R 4 together form C═O, wherein each of R 3 and R 4 is independently optionally linked to an adjacent ring structure, thereby forming a cyclic structure;

each of Y 2a , Y 2b , Y 2c , and Y 2d is independently N, NR 5 , or CR 6 , wherein each R 5 and R 6 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, amino, alkoxy, haloalkyl, arylalkyl, or arylalkenyl;

each of Y 3a , Y 3b , Y 3c , Y 3d , Y 4a , Y 4b , Y 4c , and Y 4d is independently N, O, S, NR 7 , CR 8 , wherein each R 7 and R 8 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, aminoalkoxy, haloalkyl, arylalkyl, or arylalkenyl; or Z(R 9 ) 2 , wherein Z is C or Si, and wherein each R 9 is independently hydrogen, halogen, hydroxyl, thiol, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, amino, alkoxy, haloalkyl, arylalkyl, or arylalkenyl;

each of m and n is independently 1 or 2; and

each

independently represents partial or full unsaturation of the ring with which it is associated.

2. A light emitting device comprising:

a first electrode;

a hole transporting layer in contact with the first electrode;

a second electrode;

an electron transporting layer in contact with the second electrode; and

an emissive layer between the hole transporting layer and the electron transporting layer, the emissive layer comprising: a phosphorescent emitter, a fluorescent emitter, and a host;

wherein the emissive layer comprises:

n emitter layers comprising the host and the fluorescent emitter, and

m donor layers comprising the host and the phosphorescent emitter,

wherein n and m are integers≥1, and n=m+1, or m=n+1, and the

fluorescent emitter layers and phosphorescent emitter layers alternate;

wherein the emitter layers do not comprise the phosphorescent emitter;

wherein the donor layers do not comprise the fluorescent emitter;

wherein the phosphorescent emitter is capable of harvesting electrogenerated excitons and transferring energy to the fluorescent emitter; and

wherein the phosphorescent emitter comprises a compound of General Formula I:

wherein:

M is Pt, Pd, Ir, Rh, or Au;

each of R 1 and R 2 is independently hydrogen, halogen, hydroxyl, nitro, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, amino, alkoxy, haloalkyl, arylalkyl, or arylalkenyl;

each of Y 1a , Y 1b , and Y 1c is independently O, NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(O)R 3 , or SiR 3 R 4 , wherein each of R 3 and R 4 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, amino, alkoxy, haloalkyl, arylalkyl, arylalkenyl, or R 3 and R 4 together form C═O, wherein each of R 3 and R 4 is independently optionally linked to an adjacent ring structure, thereby forming a cyclic structure;

each of Y 2a , Y 2b , Y 2c , and Y 2d is independently N, NR 5 , or CR 6 , wherein each R 5 and R 6 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, amino, alkoxy, haloalkyl, arylalkyl, or arylalkenyl;

each of Y 3a , Y 3b , Y 3c , Y 3d , Y 4a , Y 4b , Y 4c , and Y 4d is independently N, O, S, NR 7 , CR 8 , wherein each R 7 and R 8 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, aminoalkoxy, haloalkyl, arylalkyl, or arylalkenyl; or Z(R 9 ) 2 , wherein Z is C or Si, and wherein each R 9 is independently hydrogen, halogen, hydroxyl, thiol, substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocyclic group, amino, alkoxy, haloalkyl, arylalkyl, or arylalkenyl;

each of m and n is independently 1 or 2; and

each

independently represents partial or full unsaturation of the ring with which it is associated.

3. The light emitting device of claim 1 , wherein n and m are equal.

4. The light emitting device of claim 1 , wherein each emitter layer is adjacent to at least one donor layer.

5. The light emitting device of claim 1 , wherein n=m+1, or m=n+1.

6. The light emitting device of claim 1 , wherein the light emitting device is a fluorescent organic light emitting device.

7. The light emitting device of claim 1 , wherein:

M is Pt or Pd;

m in General Formula I is 2;

n in General Formula I is 2;

at least one of Y 1a and Y 1c is independently NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(O)R 3 , or SiR 3 R 4 ;

Y 2b and Y 2c are C; and

Y 3b and Y 4b are N.

8. The light emitting device of claim 1 , wherein:

M is Ir or Rh;

m in General Formula I is 2;

n in General Formula I is 2;

Y 1a is NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(O)R 3 , or SiR 3 R 4 ;

Y 2b is C; and

Y 3b , Y 2c and Y 4b are N.

9. The light emitting device of claim 1 , wherein:

M is Au;

m in General Formula I is 2;

n in General Formula I is 2;

Y 1b is NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(O)R 3 , or SiR 3 R 4 ;

Y 2b , Y 2c and Y 4b are C; and

Y 3b is N.

10. The light emitting device of claim 1 , wherein each of R 3 and R 4 is independently linked to an adjacent ring structure.

11. The light emitting device of claim 1 , wherein:

M is Pt or Pd;

at least one of Y 1b and Y 1c is independently NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(O)R 3 , or SiR 3 R 4 , wherein R 3 is covalently linked to at least one of Y 2a , Y 2d , Y 3d , and Y 4d , thereby forming a cyclic structure; and

at least of one of Y 2a , Y 2d , Y 3d and Y 4d is C.

12. The light emitting device of claim 1 , wherein:

M is Ir or Rh;

Y 1b is NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(O)R 3 , or SiR 3 R 4 , wherein R 3 is covalently linked to at least one of Y 2a and Y 3d , thereby forming a cyclic structure; and

at least of one of Y 2a and Y 3d is C.

13. The light emitting device of claim 1 , wherein:

M is Au;

at least of one of Y 2a and Y 3d is C; and

Y 1b is NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(O)R 3 , or SiR 3 R 4 , wherein R 3 is covalently linked to at least one of Y 2a and Y 3d , thereby forming a cyclic structure.

14. The light emitting device of claim 1 , wherein the fluorescent emitter comprises one of the following compounds:

wherein:

each of R 1l , R 2l , R 3l , R 4l , R 5l , R 6l , R 7l and R 8l is independently hydrogen, deuterium, halogen, hydroxyl, thiol, nitro, cyano, nitrile, isonitrile, sulfinyl, mercapto, sulfo, carboxyl, hydrazino; substituted or unsubstituted: aryl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, alkyl, alkenyl, alkynyl, amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino, alkoxy, aryloxy, haloalkyl, aralkyl, ester, alkoxycarbonyl, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, silyl, polymeric, or any conjugate or combination thereof, and

each of Y a , Y b , Y c , Y d , Y e , Y f , Y g , Y h , Y i , Y j , Y k , Y l , Y m , Y n , Y o and Y p is independently C, N or B; and

each of U a , U b and U c is independently CH 2 , CRR, C═O, SiRR, GeH2, GeRR, NH, NR, PH, PR, RP═O, AsR, RAs═O, O, S, S═O, SO 2 , Se, Se═O, SeO 2 , BH, BR, RBi═O, BiH, or BiR, wherein each R is independently is independently hydrogen, deuterium, halogen, hydroxyl, thiol, nitro, cyano, nitrile, isonitrile, sulfinyl, mercapto, sulfo, carboxyl, hydrazino; substituted or unsubstituted: aryl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, alkyl, alkenyl, alkynyl, amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino, alkoxy, aryloxy, haloalkyl, aralkyl, ester, alkoxycarbonyl, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, silyl, polymeric, or any conjugate or combination thereof.