Electroluminescent device including an anthracene derivative
An OLED device comprises a cathode, an anode, and has therebetween a light emitting layer containing a host material and an emitting dopant material wherein the host includes a monoanthracene compound bearing aromatic groups in the 2-, 9-, and 10-positions and being further substituted or not with electron donating groups sufficient so as to provide an anthracene derivative that exhibits a measured oxidation potential of less than 1.28 V.
1 . An OLED device comprising a cathode, an anode, and having therebetween a light emitting layer containing a host material and an emitting dopant material wherein the host includes a monoanthracene compound bearing aromatic groups in the 2-, 9-, and 10-positions and being further substituted or not with electron donating groups sufficient so as to provide an anthracene derivative that exhibits a measured oxidation potential of less than 1.28 V.
2 . The device of claim 1 wherein the anthracene derivative exhibits an oxidation potential of less than 1.25 V.
3 . The device of claim 1 wherein the anthracene derivative exhibits an oxidation potential of 1.20 V or less.
4 . The device of claim 1 wherein the anthracene derivative exhibits an oxidation potential between 1.10 V and 1.25 V.
5 . The device of claim 1 wherein the anthracene derivative bears at least one substituent with a σp value in the range of −0.25 to -0.50.
6 . The device of claim 1 wherein the anthracene derivative does not bear any substituent with a σp value less than −0.50.
7 . The device of claim 1 wherein the anthracene derivative bears an aromatic group in the 2-position that is further substituted with an alkoxy group.
8 . The device of claim 1 wherein the anthracene derivative bears a hydrogen or alkyl group in the 6-position.
9 . The device of claim 1 wherein the anthracene derivative bears a naphthyl group or a biphenyl group in the 9-position and a naphthyl group or a biphenyl group in the 10-position.
10 . The device of claim 1 wherein the anthracene derivative is represented by Formula (1):
wherein:
Ar 1 , Ar 2 , and Ar 3 are the same or different, and each represents an aromatic group;
w 1 through w 7 represent hydrogen or a substituent.
11 . The device of claim 10 wherein at least one of Ar 1 , Ar 2 , and Ar 3 bears a substituent with a σp value of −0.25 or lower.
12 . The device of claim 1 wherein the anthracene derivative is represented by Formula (2):
wherein:
each r 1 , r 2 , and r 3 are the same or different, and each represents a substituent group, provided adjacent substituents may combine to form a ring group, and provided at least one of r 1 , r 2 , and r 3 represents a group with a up value in the range of −0.25 to −0.50;
m, n, and p are independently 0-5, provided m, n, and p are not all 0; and
w 1 through w 7 represent hydrogen or a substituent.
13 . The device of claim 12 wherein at least one r 3 has a σp value of −0.25 or lower.
14 . The device of claim 1 wherein the emitting dopant material comprises a boron atom.
15 . The device of claim 1 including a further layer located between the light-emitting layer and the cathode wherein the further layer includes an electron-transporting material having an anthracene or tetracene nucleus.
16 . The device of claim 15 wherein the electron-transporting material in the further layer includes an anthracene nucleus substituted with aromatic groups in the 2-, 9-, and 10-positions.
17 . The device of claim 15 wherein an additional layer is located between the further layer and the cathode and wherein the additional layer includes a material comprising a phenanthroline nucleus or a metal complex comprising an 8-quinolinolate nucleus.
18 . An OLED device comprising a cathode, an anode, and having therebetween a light emitting layer containing a host material and an emitting dopant material wherein the host includes an anthracene compound bearing aromatic groups in the 9-, and 10-positions and including an aromatic group having no more than two fused rings in the 2-position and said anthracene compound being further substituted or not with electron donating groups sufficient so as to provide an anthracene derivative that exhibits an oxidation potential of less than 1.25 V.
19 . The device of claim 18 wherein the anthracene compound exhibits an oxidation potential of 1.20 V or less.
20 . The device of claim 18 including a further layer located between the light-emitting layer and the cathode wherein the further layer includes an electron-transporting material comprising an anthracene nucleus.