Light-emitting element
AssigneeSumitomo Chemical Company, Limited
InventorsTakayuki IIJIMA, Kyoko YAMAMOTO
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Abstract
A light-emitting device having a high current efficiency is provided. The light-emitting device includes, in sequence, a cathode, an electron transport layer, a light-emitting layer, and an anode. The light-emitting device further optionally includes an electron injection layer between the cathode and the electron transport layer. The electron transport layer contains particles and a non-particle electron transport material. A refractive index of light n1 at a wavelength of 550 nm of a material that constitutes the particles and a refractive index of light n2 at a wavelength of 550 nm of the non-particle electron transport material satisfies the following relation: n1−n2≤−0.15. The particles have a Z-average size of 110 to 300 nm as determined by dynamic light scattering.
Claims8
A light-emitting device comprising, in sequence, a cathode, an electron transport layer, a light-emitting layer, and an anode,
- the light-emitting device further optionally comprising an electron injection layer between the cathode and the electron transport layer,
- wherein:
- the electron transport layer contains particles and a non-particle electron transport material,
- a refractive index of light n1 at a wavelength of 550 nm of a material that constitutes the particles and a refractive index of light n2 at a wavelength of 550 nm of the non-particle electron transport material satisfy the following relation:
- n1−n2≤−0.15,
- the particles have a Z-average size of 110 to 300 nm as determined by dynamic light scattering, and
- the proportion of the particles is 1 to 200 parts by mass relative to 100 parts by mass of the electron transport material.
(canceled)
Dependencies are inferred from the claim text.