OLED with multi-emissive material layer
The present invention relates to organic light emitting devices with a multi-emissive material layer (EML), where a multi-EML generally refers to an emissive layer having at least two layers of emissive material, each layer having a different emitter concentration (e.g. a first EML in direct contact with a second EML, and the emitter concentration of the first EML (hole favorable) exceeds that of the second EML (electron favorable)).
1. An organic light emitting device comprising:
an anode;
a cathode; and
an emissive layer between the anode and the cathode, the emissive layer comprising a first emissive layer in direct contact with a second emissive layer, the first emissive layer comprising a first emitter and a host and the second emissive layer comprising a second emitter and a host,
the concentration of the first emitter in the first emissive layer exceeds the concentration of the second emitter in the second emissive layer;
wherein the concentration of the host in the first emissive layer is less than the concentration of the host in the second emissive layer
wherein the difference between the concentration of the first emitter in the first emissive layer and the concentration of the second emitter in the second emissive layer is equal to the difference between the concentration of the host in the second emissive layer and the concentration of the host in the first emissive layer; and
wherein the second emissive layer is positioned between the first emissive layer and the cathode;
wherein each of the first emitter and the second emitter comprises an organometallic complex represented by Formula I:
wherein:
M is Pt, Pd, or Ir;
R 1 , R 2 , R 3 , R 4 , R 8 , R 9 , and R 10 each independently represents hydrogen, halogen, hydroxy, amino, nitro, thiol, substituted or unsubstituted C 1 -C 4 alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl;
Y 1a represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, N, NR 5a , P, PR 5a , As, AsR 5a , O═NR 5a , O═PR 5a , O═AsR 5a , B, BR 5a , SiR 5a , SiR 5a R 5b , CR 5a , or CR 5a R 5b;
Y 1b and Y 1c each independently represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, N, NR 5a , P, PR 5a , As, AsR 5a , O═NR 5a , O═PR 5a , O═AsR 5a , B, BR 5a , SiR 5a , SiR 5a R 5b , CR 5a , CR 5a R 5b , or a single bond, wherein if Y 1b represents a single bond, Y 2e and Y 4c are directly linked by a single bond, and if Y 1c represents a single bond, Y 2b and Y 3c are directly linked by a single bond;
Y 2a , Y 2b , Y 2c , Y 2d , Y 2e , and Y 2f each independently represents C or N;
provided that only one of Y 2c and Y 2d represent N;
R 5a , R 5b , and R 5c each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
R 6a , R 6b , and R 6c each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
R 7a , R 7b , and R 7c each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
Y 3a , Y 3b , Y 3c , Y 3d , and Y 3e each independently represents C, N, Si, O, or S;
Y 4a , Y 4b , Y 4c , Y 4d , and Y 4e each independently represents C, N, Si, O, or S;
each of L 1 , L 2 , L 3 , L 4 , L 5 , and L 6 is independently absent or represents a linking group;
represents one of the following:
wherein Z 1 , Z 2 independently represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, NR 5a , PR 5a , AsR 5a , O═NR 5a , O═PR 5a , O═AsR 5a , BR 5a , SiR 5a R 5b , or CR 5a R 5b ;
represents one of the following:
wherein Z 3 and Z 4 each independently represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, NR 6a , PR 6a , AsR 6a , O═NR 6a , O═PR 6a , O═AsR 6a , BR 6a , SiR 6a R 6b , or CR 6a R 6b ;
represents one of the following:
wherein Z 5 and Z 6 each independently represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, NR 7a , PR 7a , AsR 7a , O═NR 7a , O═PR 7a , O═AsR 7a , BR 7a , SiR 7a R 7b , or CR 7a R 7b;
Ar 3 and Ar 4 each independently represents a substituted or unsubstituted 5-membered ring or a 6-membered aromatic ring; and
n is 0, 1, 2, 3, 4, 5, or 6.
2. The organic light emitting device of claim 1 , wherein the emissive layer comprises a third emissive layer comprising a third emitter and a host,
wherein the third emissive layer is in direct contact with the second emissive layer,
the concentration of the second emitter in the second emissive layer exceeds the concentration of the third emitter in the third emissive layer;
the concentration of the host in the second emissive layer is less than the concentration of the host in the third emissive layer; and
wherein the third emissive layer is positioned between the second emissive layer and the cathode.
3. The organic light emitting device of claim 2 , wherein the emissive layer comprises a fourth emissive layer comprising a fourth emitter and a host,
wherein the fourth emissive layer is in direct contact with the third emissive layer,
the concentration of the third emitter in the third emissive layer exceeds the concentration of the fourth emitter in the fourth emissive layer;
the concentration of the host in the third emissive layer is less than the concentration of the host in the fourth emissive layer; and
wherein the fourth emissive layer is positioned between the third emissive layer and the cathode.
4. The organic light emitting device of claim 1 , wherein the first emitter and the second emitter are the same.
5. The organic light emitting device of claim 1 , wherein at least one of the first and second emitters emits red or blue light.
6. The organic light emitting device of claim 1 , wherein the organometallic complex is represented by Formula II:
wherein:
M is Pt, Pd, or Ir;
R 1 , R 2 , R 3 , and R 4 each independently represents hydrogen, halogen, hydroxy, amino, nitro, thiol, substituted or unsubstituted C 1 -C 4 alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl;
Y 1a represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, NR 5a , PR 5a , AsR 5a , O═NR 5a , O═PR 5a , O═AsR 5a , BR 5a , SiR 5a R 5b , or CR 5a R 5b;
Y 2a , Y 2c , Y 2d , and Y 2f each independently represents C or N;
provided that only one of Y 2c and Y 2d represent N;
R 5a , R 5b , and R 5c each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
Y 3a , Y 3b , Y 3d , and Y 3e each independently represents C, N, or Si;
Y 4a , Y 4b , Y 4d , and Y 4e each independently represents C, N, or Si;
n is 0, 1, 2, 3, or 4.
7. The organic light emitting device of claim 1 , wherein the organometallic complex is represented by Formula III:
wherein:
M is Pt, Pd, or Ir;
R 1 , R 2 , R 3 , and R 4 each independently represents hydrogen, halogen, hydroxy, amino, nitro, thiol, substituted or unsubstituted C 1 -C 4 alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl;
Y 1a represents N, P, As, B, SiR 5a , or CR 5a;
Y 1b represents N, P, As, B, SiR 5a , or CR 5a;
Y 2c , Y 2d , and Y 2f each independently represents C or N;
provided that only one of Y 2d and Y 2c represent N;
R 5a each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
Y 3a , Y 3b , Y 3d , and Y 3e each independently represents C, N, or Si;
Y 4a , Y 4b , Y 4d , and Y 4e each independently represents C, N, or Si; and
n is 0, 1, 2, 3, 4, or 5.
8. The organic light emitting device of claim 7 , wherein:
M is Pt or Pd;
R 1 , R 2 , R 3 , and R 4 each independently represents hydrogen, halogen, hydroxy, amino, nitro, thiol, substituted or unsubstituted C 1 -C 4 alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl;
Y 1a represents N, P, SiR 5a , or CR 5a;
Y 1b represents N, P, SiR 5a , or CR 5a;
Y 2c , Y 2d , and Y 2f each independently represents C or N;
provided that only one of Y 2d and Y 2c represent N;
R 5a each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
Y 3a , Y 3b , Y 3d , and Y 3e each independently represents C or N;
Y 4a , Y 4b , Y 4d , and Y 4e each independently represents C or N; and
n is 0, 1, or 2.
9. The organic light emitting device of claim 1 , wherein the organometallic complex is represented by Formula IV:
wherein:
M is Pt, Pd, or Ir;
R 1 , R 2 , R 3 , or R 4 each independently represents hydrogen, halogen, hydroxy, amino, nitro, thiol, substituted or unsubstituted C 1 -C 4 alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl;
Y 1a represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, NR 5a , PR 5a , AsR 5a , O═NR 5a , O═PR 5a , O═AsR 5a , BR 5a , SiR 5a R 5b , or CR 5a R 5b;
Y 1b and Y 1c each independently represents N, P, As, B, SiR 5a , or CR 5a,
Y 2c or Y 2d each independently represents C or N;
provided that only one of Y 2d and Y 2c represent N;
R 5a and R 5b each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
Y 3a , Y 3b , Y 3d , and Y 3e each independently represents C, N, or Si;
Y 4a , Y 3b , Y 3d , and Y 4e each independently represents C, N, or Si; and
n is 0, 1, 2, 3, 4, or 5.
10. The organic light emitting device of claim 1 , wherein the organometallic complex has one of the following structures:
11. The organic light emitting device of claim 1 , comprising an electron blocking layer between the anode and the emissive layer.
12. The organic light emitting device of claim 11 , wherein the electron blocking layer comprises a host material and a dopant.
13. The organic light emitting device of claim 12 , wherein host material comprises a carbazole-based material.
14. The organic light emitting device of claim 13 , wherein the carbazole-based material comprises one of the following structures:
wherein each of R 1 -R 9 is independently hydrogen, nitro, hydroxyl, halogen, or substituted or unsubstituted amino, thio, alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkane, cycloalkane, heterocyclyl, alkoxy, haloalkyl, arylalkane, or arylalkene.
15. The organic light emitting device of claim 12 , wherein the dopant is a fluorescent material.
16. The organic light emitting device of claim 15 , wherein the fluorescent material comprises one of the following structures:
1. Aromatic Hydrocarbons and Their Derivatives
2. Arylethylene, Arylacetylene and Their Derivatives
3. Heterocyclic Compounds and Their Derivatives
wherein:
each of R 11 , R 21 , R 31 , R 41 , R 51 , R 61 , R 71 , and R 81 is independently a mono-, di-, or tri-substitution, and if present each of R 11 , R 21 , R 31 , R 41 , R 51 , R 61 , R 71 , and R 81 is independently hydrogen, deuterium, halogen, hydroxyl, thiol, nitro, cyano, nitrile, isonitrile, sulfinyl, mercapto, sulfo, carboxyl, hydrazino; substituted or unsubstituted: aryl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, substituted or unsubstituted alkyl, alkenyl, alkynyl, amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino, alkoxy, aryloxy, haloalkyl, aralkyl, ester, alkoxycarbonyl, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, or silyl,
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,
each of U a , U b , and U c is independently CH 2 , CR 1 R 2 , C═O, CH 2 , SiR 1 R 2 , GeH 2 , GeR 1 R 2 , NH, NR 3 , PH, PR 3 , R 3 P═O, AsR 3 , R 3 As═O, O, S, S═O, SO 2 , Se, Se═O, SeO 2 , BH, BR 3 , R 3 Bi═O, BiH, or BiR 3 , and
each of W, W a , W b , and W c is independently CH, CR 1 , SiR 1 , GeH, GeR 1 , N, P, B, Bi, or Bi═O.
17. An organic light emitting device comprising:
an anode;
a cathode;
an emissive layer between the anode and the cathode, the emissive layer comprising a first emissive layer in direct contact with a second emissive layer, the first emissive layer comprising a first emitter and a host and the second emissive layer comprising a second emitter and a host,
wherein the concentration of the first emitter in the first emissive layer exceeds the concentration of the second emitter in the second emissive layer;
wherein the concentration of the host in the first emissive layer is less than the concentration of the host in the second emissive layer
wherein the difference between the concentration of the first emitter in the first emissive layer and the concentration of the second emitter in the second emissive layer is equal to the difference between the concentration of the host in the second emissive layer and the concentration of the host in the first emissive layer; and
wherein the second emissive layer is positioned between the first emissive layer and the cathode; and
wherein each of the first emitter and the second emitter comprises an organometallic complex represented by Formula I:
wherein:
M is Pt or Pd;
R 1 , R 2 , R 3 , R 4 , R 8 , R 9 , and R 10 each independently represents hydrogen, halogen, hydroxy, amino, nitro, thiol, substituted or unsubstituted C 1 -C 4 alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl;
Y 1a represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, N, NR 5a , P, PR 5a , As, AsR 5a , O═NR 5a , O═PR 5a , O═AsR 5a , B, BR 5a , SiR 5a , SiR 5a R 5b , CR 5a , or CR 5a R 5b;
Y 1b and Y 1c each independently represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, N, NR 5a , P, PR 5a , As, AsR 5a , O═NR 5a , O═PR 5a , O═AsR 5a , B, BR 5a , SiR 5a , SiR 5a R 5b , CR 5a , CR 5a R 5b , or a single bond, wherein if Y 1b represents a single bond, Y 2e and Y 4c are directly linked by a single bond, and if Y 1c represents a single bond, Y 2b and Y 3c are directly linked by a single bond;
Y 2a , Y 2b , Y 2c , Y 2d , Y 2e , and Y 2f each independently represents C or N;
R 5a , R 5b , and R 5c each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
R 6a , R 6b , and R 6c each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
R 7a , R 7b , and R 7c each independently represents substituted or unsubstituted C 1 -C 4 alkyl or substituted or unsubstituted aryl;
Y 3a , Y 3b , Y 3c , Y 3d , and Y 3e each independently represents C, N, Si, O, or S;
Y 4a , Y 4b , Y 4c , Y 4d , and Y 4e each independently represents C, N, Si, O, or S;
each of L 1 , L 2 , L 3 , L 4 , L 5 , and L 6 is independently absent or represents a linking group;
represents one of the following:
wherein Z 1 , Z 2 independently represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, NR 5a , PR 5a , AsR 5a , O═NR 5a , O═PR 5a , O═AsR 5a , BR 5a , SiR 5a R 5b , or CR 5a R 5b ;
represents one of the following:
represents one of the following:
wherein Z 3 and Z 4 each independently represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, NR 6a , PR 6a , AsR 6a , O═NR 6a , O═PR 6a , O═AsR 6a , BR 6a , SiR 6a R 6b , or CR 6a R 6b ;
represents one of the following:
wherein Z 5 and Z 6 each independently represents O, S, S═O, O═S═O, Se, Se═O, O═Se═O, NR 7a , PR 7a , AsR 7a , O═NR 7a , O═PR 7a , O═AsR 7a , BR 7a , SiR 7a R 7b , or CR 7a R 7b ;
Ar 3 and Ar 4 each independently represents a substituted or unsubstituted 5-membered ring or a 6-membered aromatic ring; and
n is 0, 1, 2, 3, 4, 5, or 6.