Light emitting polymer devices with improved efficiency and lifetime
First Claim
1. An OLED device, comprising:
- a substrate;
an anode on said substrate;
a first hole injection/transport layer on said anode;
a second hole injection/transport layer on said first hole injection/transport layer;
an emissive layer on said second hole injection/transport layer; and
a cathode on said emissive layer, wherein said second hole injection/transport layer has a range of ionization potentials (“
IPs”
) between a highest IP of an adjacent layer on an anode-end and a lowest IP of an adjacent layer on an “
emissive layer”
-end.
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Accused Products
Abstract
In one embodiment of an OLED device, a hole injection/transport layer is added to the device structure in order to increase the number of holes injected into the emissive layer and reduce the number of electrons injected into the added hole injection/transport layer. In a first configuration of the added hole injection/transport layer, the added hole injection/transport layer is comprised of a non-doped hole transporting material that has an IP range between the highest IP value of the adjacent layer on the anode-end and the lowest IP value of the adjacent layer on the “emissive layer”-end. Optionally, in addition, nearly all electron affinities of the added hole injection/transport layer are less than the lowest electron affinity of the adjacent layer on the “emissive layer”-end. In a second configuration of the added hole injection/transport layer, this layer is formed by doping the hole transport material. The dopant is able to abstract electrons from the hole transporting material. By doping the hole transport material, the IP range of the hole transporting material is broadened. In addition or alternatively, the doping produces more HOMO energy states thus allowing more holes to occupy these intermediate states at any one time.
42 Citations
32 Claims
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1. An OLED device, comprising:
-
a substrate;
an anode on said substrate;
a first hole injection/transport layer on said anode;
a second hole injection/transport layer on said first hole injection/transport layer;
an emissive layer on said second hole injection/transport layer; and
a cathode on said emissive layer, wherein said second hole injection/transport layer has a range of ionization potentials (“
IPs”
) between a highest IP of an adjacent layer on an anode-end and a lowest IP of an adjacent layer on an “
emissive layer”
-end. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method to fabricate an OLED device, comprising:
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depositing an anode on a substrate;
depositing a first hole injection/transport layer on said anode;
depositing a second hole injection/transport layer on said first hole injection/transport layer;
depositing an emissive layer on said second hole injection/transport layer; and
depositing a cathode on said emissive layer, wherein said second hole injection/transport layer has a range of IPs between a highest IP of an adjacent layer on an anode-end and a lowest IP of an adjacent layer on an “
emissive layer”
-end. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. An OLED device, comprising:
-
a substrate;
an anode on said substrate;
a hole injection/transport layer on said anode;
an emissive layer on said hole injection/transport layer; and
a cathode on said emissive layer, wherein said hole injection/transport layer is comprised of a hole transport material that is doped with a dopant that is able to abstract electrons from said hole transport material, and said hole injection/transport layer has a range of IPs between a highest IP of an adjacent layer on an anode-end and a lowest IP of an adjacent layer on an “
emissive layer”
-end, and nearly all electron affinities of said hole injection/transport layer are less than the lowest electron affinity of said adjacent layer on said “
emissive layer”
-end. - View Dependent Claims (25, 26, 27)
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28. An OLED device, comprising:
-
a substrate;
a cathode on said substrate;
an emissive layer on said cathode;
a first hole injection/transport layer on said emissive layer;
a second hole injection/transport layer on said first hole injection/transport layer; and
an anode on said second hole injection/transport layer, wherein said first hole injection/transport layer has a range of IPs between a highest IP of an adjacent layer on an anode-end and a lowest IP of an adjacent layer on an “
emissive layer”
-end. - View Dependent Claims (29, 30, 31, 32)
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Specification