Organic electroluminescent device
AssigneeIdemitsu Kosan Co., Ltd.
InventorsHitoshi Kuma, Yuichiro Kawamura, Yukitoshi Jinde, Toshinari Ogiwara, Chishio Hosokawa
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Abstract
An organic electroluminescence device including an anode, an emitting layer, a blocking layer, an electron-injecting layer and a cathode in sequential order; wherein the emitting layer contains a host and a dopant which gives fluorescent emission of which the main peak wavelength is 550 nm or less; the affinity Ad of the dopant is smaller than the affinity Ah of the host; the triplet energy ETd of the dopant is larger than the triplet energy ETh of the host; the triplet energy ETb of the blocking layer is larger than ETh; and the blocking layer includes an aromatic hydrocarbon compound.
Claims16
An organic electroluminescence device comprising an anode, an emitting layer, a blocking layer, an electron-injecting layer and a cathode in sequential order;
- wherein
- the emitting layer contains a host and a dopant which gives fluorescent emission of which the main peak wavelength is 550 nm or less;
- the affinity Ad of the dopant is smaller than the affinity Ah of the host;
- the triplet energy ETd of the dopant is larger than the triplet energy ETh, of the host;
- the triplet energy ETb of the blocking layer is larger than ETh;
- and
- the blocking layer comprises an aromatic hydrocarbon compound.
An organic electroluminescence device comprising an anode, an emitting layer, an electron-transporting region and a cathode in sequential order, wherein
- the emitting layer contains a host and a dopant which gives fluorescent emission of which the main peak wavelength is 550 nm or less;
- the affinity Ad of the dopant is smaller than the affinity Ah of the host;
- the triplet energy ETd of the dopant is larger than the triplet energy ETh of the host;
- a blocking layer is provided in the electron-transporting region such that it is adjacent to the emitting layer, and the triplet energy ETb of a material constituting the blocking layer is larger than ETh;
- and
- at an applied voltage which makes current efficiency (unit:
- cd/A) maximum, a luminous intensity derived from singlet excitons generated by collision of triplet excitons generated in the emitting layer is 30% or more of the total luminous intensity.
Dependencies are inferred from the claim text.