Organic electroluminescence device
View Patent ↗Provided are a light emitting layer including molten salt and an organic electroluminescent device comprising the light emitting layer. When the organic electroluminescent device is operated, a field induction charge separation layer is formed in the light emitting layer including the molten salt and thus, carrier injection is improved, thereby providing a light emitting layer having improved light emitting efficiency. An organic electroluminescent device including the light emitting layer has low operating voltage and long lifespan.
1. A composition for forming a light emitting layer, comprising:
light emitting material; and
molten salt,
wherein the molten salt is represented by Formula 2:
where X 1 is a substituted or unsubstituted C 1 -C 10 alkylene group, a substituted or unsubstituted C6-C30 arylene group, a substituted or unsubstituted C1-C20 heteroalkylene group, or a substituted or unsubstituted C4-C30 heteroarylene group;
X 2 is sulfonate-based anion, cyanate-based anion, thiocyanate-based anion, or carboxylate-based anion;
R 3 , R 4 , R 5 and R 6 are each independently hydrogen, a halogen atom, a carboxyl group, an amino group, a nitro group, a cyano group, a hydroxy group, a substituted or unsubstituted C 1 -C 20 alkyl group, a substituted or unsubstituted C 1 -C 20 alkoxy group, a substituted or unsubstituted C 1 -C 20 silicon containing group, a substituted or unsubstituted C 1 -C 20 fluorine containing group, a substituted or unsubstituted C 2 -C 20 alkenyl group, a substituted or unsubstituted C 2 -C 20 alkynyl group, a substituted or unsubstituted C 1 -C 20 heteroalkyl group, a substituted or unsubstituted C 6 -C 30 aryl group, a substituted or unsubstituted C 7 -C 30 arylalkyl group, a substituted or unsubstituted C 5 -C 30 heteroaryl group, or a substituted or unsubstituted C 3 -C 30 heteroarylalkyl group; and
n is an integer in a range of 50 to 500.
2. The composition of claim 1 , wherein the molten salt has an average number molecular weight of 1,000 to 30,000.
3. The composition of claim 1 , wherein the amount of molten salt is 0.001 to 20% by weight based on a total weight of the light emitting material.
4. The composition of claim 1 , wherein the light emitting material comprises at least one host selected from the group consisting of a polymer host, a mixture host of a polymer and a small molecule, a small molecule host, and a non-emitting polymer matrix.
5. The composition of claim 1 , further comprising a polar solvent mixed with the molten salt.
6. A light emitting layer comprising the composition of claim 1 .
7. An organic electroluminescent device comprising the light emitting layer of claim 6 .
8. An organic electroluminescent device, comprising:
a first electrode;
a second electrode; and
a light emitting layer interposed between the first electrode and the second electrode, the light emitting layer formed by coating and drying a composition, the composition comprising:
light emitting material; and
molten salt wherein the molten salt is represented by Formula 2:
where X 1 is a substituted or unsubstituted C 1 -C 10 alkylene group, a substituted or unsubstituted C6-C30 arylene group, a substituted or unsubstituted C1-C20 heteroalkylene group, or a substituted or unsubstituted C4-C30 heteroarylene group;
X 2 is sulfonate-based anion, cyanate-based anion, thiocyanate-based anion, or carboxylate-based anion;
R 3 , R 4 , R 5 and R 6 are each independently hydrogen, a halogen atom, a carboxyl group, an amino group, a nitro group, a cyano group, a hydroxy group, a substituted or unsubstituted C 1 -C 20 alkyl group, a substituted or unsubstituted C 1 -C 20 alkoxy group, a substituted or unsubstituted C 1 -C 20 silicon containing group, a substituted or unsubstituted C 1 -C 20 fluorine containing group, a substituted or unsubstituted C 2 -C 20 alkenyl group, a substituted or unsubstituted C 2 -C 20 alkynyl group, a substituted or unsubstituted C 1 -C 20 heteroalkyl group, a substituted or unsubstituted C 6 -C 30 aryl group, a substituted or unsubstituted C 7 -C 30 arylalkyl group, a substituted or unsubstituted C 5 -C 30 heteroaryl group, or a substituted or unsubstituted C 3 -C 30 heteroarylalkyl group; and
n is an integer in a range of 50 to 500.