Organic EL element, organic EL panel having organic EL element, organic EL light-emitting apparatus, and organic EL display apparatus
View Patent ↗An organic EL element comprises: an anode; a cathode; a buffer layer; and a hole injection layer between the anode and the buffer layer. The hole injection layer includes a nickel oxide that includes both nickel atoms with a valence of three and nickel atoms with a valence of two. At least part of the hole injection layer has a crystal structure A a Ni b O c that includes nickel, a metal element A, and oxygen, the nickel including nickel atoms with a valence of three, and the metal element A differing from nickel and including metal A atoms with a valence of three.
1. An organic EL element, comprising:
an anode;
a cathode;
an organic functional layer between the anode and the cathode, the organic functional layer including an organic material; and
a metal oxide layer between the anode and the organic functional layer, the metal oxide layer including a nickel oxide that includes both nickel atoms with a valence of three and nickel atoms with a valence of two, wherein
a difference in energy between an upper end of a valence band of the metal oxide layer and a Fermi level of the metal oxide layer is less than or equal to 0.8 eV,
a value resulting from subtraction of an ionization potential of the organic functional layer from an ionization potential of the metal oxide layer is greater than or equal to 0 eV,
at least part of the metal oxide layer has a crystal structure ANiO 3 that includes nickel, a metal element A, and oxygen,
the metal element A in the crystal structure ANiO 3 is one of bismuth consisting of bismuth atoms with a valence of three and lanthanum consisting of lanthanum atoms with a valence of three, and
the nickel in the crystal structure ANiO 3 consists of nickel atoms with a valence of three which allows the crystal structure ANiO 3 to be electrically neutral as a whole.
2. The organic EL element of claim 1 , wherein
the metal element A is bismuth.
3. The organic EL element of claim 1 , wherein
the metal element A is lanthanum.
4. The organic EL element of claim 1 , wherein
the crystal structure ANiO 3 is a perovskite structure.
5. The organic EL element of claim 1 , wherein
the organic material in the organic functional layer is an amine-based compound.
6. The organic EL element of claim 1 , wherein
the organic functional layer is one of a light-emitting layer, a hole transporting layer, and a buffer layer, the light-emitting layer emitting light as a result of recombination of holes and electrons, the holes being injected from the anode via the metal oxide layer, the electrons being injected from the cathode, the hole transport layer transporting the holes injected from the metal oxide layer to the light-emitting layer, and the buffer layer preventing the electrons injected from the cathode from entering the anode.
7. An organic EL panel including the organic EL element of claim 1 in a plurality.
8. An organic EL light-emitting apparatus including the organic EL element of claim 1 in a plurality, and a circuit configured to drive the organic EL elements.
9. An organic EL display apparatus including the organic EL element of claim 1 in a plurality, and a circuit configured to drive the organic EL elements.