Metal-assisted delayed fluorescent materials as co-host materials for fluorescent OLEDs

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 metal-assisted delayed fluorescent (MADF) emitter, a fluorescent emitter, and a host, wherein the MADF emitter harvests electrogenerated singlet and triplet excitons and transfers energy to the fluorescent emitter.

2. The light emitting device of claim 1 , wherein the energy transfer is from a triplet of the MADF emitter to a singlet of the fluorescent emitter.

3. The light emitting device of claim 1 , wherein the energy transfer is from a singlet of the MADF emitter to a singlet of the fluorescent emitter.

4. 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;

wherein the emissive layer comprises:

n emitter layers comprising a host and a fluorescent emitter; and

m donor layers comprising a host and a metal-assisted delayed fluorescent (MADF) emitter,

wherein n and m are integers ≥1;

wherein n=m+1;

wherein each emitter layer is adjacent to at least one donor layer; and

wherein the MADF emitter harvests electrogenerated singlet and triplet excitons and transfers energy to the fluorescent emitter.

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

wherein R al , R bl , R cl , R dl , R el , R fl , R gl , R hl and R il can be one of the following structure:

3. Heterocyclic Compounds and Their Derivatives

4. Other fluorescent luminophors

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, GeH 2 , GeRR 2 , 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 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.

6. The light emitting device of claim 5 , wherein the fluorescent emitter comprises one of the following structures:

7. The light-emitting device of claim 1 , wherein light emission from the light-emitting device is primarily from the fluorescent emitter.

8. The light emitting device of claim 1 , wherein the MADF emitter is a compound of structure (a) or (b):

wherein:

M is platinum (II), palladium (II), nickel (II), manganese (II), zinc (II), gold (III), silver (III), copper (III), iridium (I), rhodium (I), or cobalt (I);

A is an accepting group having one of the following structures, which can optionally be substituted:

D is a donor group having one of the following structures, which can optionally be substituted:

C has one of the following structures, which can optionally be substituted:

N has one of the following structures, which can optionally be substituted:

each of a 0 , a 1 , and a 2 is independently present or absent, and if present, is a direct bond or linking group having one of the following structures:

each of b 1 and b 2 is independently present or absent, and if present, comprises a linking group comprising one or more of the following structures:

X is B, C, N, O, Si, P, S, Ge, As, Se, Sn, Sb, or Te,

Y is N, P, P═O, As, As═O, CH, CR, SiH, SiR, GeH, GeR,

each R 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, alkoxy carbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, silyl, polymeric, or any conjugate or combination thereof, and

n is an integer that satisfies the valency of Y.

9. The light emitting device of claim 8 , wherein a 2 is absent.

10. The light emitting device of claim 8 , wherein a 2 and b 2 are absent.

11. The light emitting device of claim 8 , wherein X is N.

12. The light emitting device of claim 8 , wherein A is

a 2 is absent, b 2 is absent, and D is

13. The light emitting device of claim 8 , wherein C in structure (a) or (b) is

14. The light emitting device of claim 8 , wherein N in structure (a) or (b) is

or substituted

15. The light emitting device of claim 8 , wherein M is platinum (II) or palladium (II).

16. The light emitting device of claim 1 , wherein the fluorescent emitter has the following structure:

17. The light emitting device of claim 8 , wherein the MADF emitter is a compound of General Formula A:

wherein:

M is Pt, Pd, Au, Ir, Rh, Mn, Ni, Cu, or Ag;

each R 1 and R 2 is independently hydrogen, halogen, hydroxyl, nitro, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene;

each of Y 1a and Y 1b is independently O, NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , B(R 3 ) 2 , PR 3 , P(O)R 3 , or SiR 3 R 4 , or a combination thereof, wherein each of R 3 and R 4 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, arylalkene, 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 or CR 5 , wherein R 5 is hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene;

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 6 , or CR 7 , wherein each of R 6 and R 7 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene; or Z(R 8 ) 2 , wherein Z is C or Si, and wherein each R 8 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene;

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.

18. The light emitting device of claim 8 , wherein the MADF emitter is a compound of General Formula D:

wherein:

M is Ir, Rh, Pt, Os, Zr, Co, or Ru;

each of R 1 and R 2 is independently hydrogen, halogen, hydroxyl, nitro, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene;

each of Y 1a , Y 1b , Y 1c and Y 1d 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, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, arylalkene, 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;

Y 1e , if present, is O, NR 3 , CR 3 R 4 , S, AsR 3 , BR 3 , PR 3 , P(0)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, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, arylalkene, 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 or CR 5 , wherein R 5 is hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene;

each of Y 3a , Y 3b , Y 3c , Y 3d , Y 3e , Y 4a , Y 4b , Y 4c , and Y 4d is independently N, O, S, NR 6 , or CR 7 , wherein each of R 6 and R 7 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene; or Z(R 8 ) 2 , wherein Z is C or Si, and wherein each R 8 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene;

each of Y 5a , Y 5b , Y 5c , Y 5d , Y 6a , Y 6b , Y 6c , and Y 6d is independently N, O, S, NR 5 , or

CR 6 ; each of m, n, I, and p is independently 1 or 2; and

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

19. The light emitting device of claim 8 , wherein the MADF emitter is a compound of General Formula E:

wherein:

M is Pt, Pd, Ir, Rh, Au, Co, Mn, Ni, Ag, or Cu;

each of Y 1a and Y 1b 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, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, arylalkene, 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 , Y 2d , Y 2e , Y 2f , Y 2g , and Y 2h is independently N or CR 5 , wherein R 5 is hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene;

each of Y 3a , Y 3b , Y 3c , Y 3d , Y 3e , Y 4a , Y 4b , Y 4c , Y 4d and Y 4e is independently N, O, S, NR 6 , or CR 7 , wherein each of R 6 and R 7 independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, amino, alkoxy, haloalkyl, arylalkane, or arylalkene; or Z(R 8 ) 2 , wherein Z is C or Si, and wherein each R 8 is independently hydrogen, halogen, hydroxyl, thiol, or substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, aminoalkoxy, haloalkyl, arylalkane, or arylalkene;

m is 1 or 2;

n is 1 or 2;

each independently represents partial or full unsaturation of the ring with which it is associated; and

each of Fl 1 , Fl 2 , Fl 3 and Fl 4 is independently present or absent, with at least one of Fl 1 , Fl 2 , Fl 3 and Fl 4 present, and if present each of Fl 1 , Fl 2 , Fl 3 and Fl 4 is a fluorescent emitter covalently bonded to one of Y 2a , Y 2d , Y 2e , Y 2f , Y 2g , Y 2h , Y 3c , Y 3d , Y 3e Y 4c , Y 4d and Y 4e .

20. The light emitting device of claim 19 , wherein each of Fl 1 , Fl 2 , Fl 3 , Fl 4 , if present, has one of the following structures:

1. Aromatic Hydrocarbons and Their Derivatives

2. Arylethylene, Arylacetylene and Their Derivatives

wherein R al , R bl , R cl , R dl , R el , R fl , R gl , R hl and R il can be one of the following structure:

3. Heterocyclic Compounds and Their Derivatives

4. Other fluorescent luminophors

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 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, GeH 2 , GeRR 2 , 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 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.