CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Application No. PCT/JP2020/041596 filed on Nov. 6, 2020, which application claims priority to Japanese Application No. 2019-203404, filed on Nov. 8, 2019. The entire contents of the above applications are incorporated herein by reference in their entireties.

TECHNICAL FIELD

Background Art

An organic electroluminescence device (hereinafter, occasionally referred to as “organic EL device”) has found its application in a full-color display for mobile phones, televisions and the like. When a voltage is applied to the organic EL device, holes are injected from an anode and electrons are injected from a cathode into an emitting layer. The injected electrons and holes are recombined in the emitting layer to form excitons. Specifically, according to the electron spin statistics theory, singlet excitons and triplet excitons are generated at a ratio of 25%:75%.

Various studies have been made for compounds to be used for the organic EL device in order to enhance the performance of the organic EL device. The performance of the organic EL device is evaluable in terms of, for instance, luminance, emission wavelength, chromaticity, luminous efficiency, drive voltage, and lifetime.

For example, Patent Literature 1 describes an organic electroluminescence device including: an emitting layer containing a pyrene derivative and provided close to an anode; and an emitting layer containing an anthracene derivative and provided close to a cathode.

For example, Patent Literature 2 describes an organic electroluminescence device including an emitting layer containing an anthracene derivative as a host material and a pyrene derivative as a dopant material.

For example, Patent Literature 3 describes an organic electroluminescence device including: an emitting layer containing a pyrene derivative as a host material and provided close to an anode; and an emitting layer containing an anthracene derivative as the host material and provided close to a cathode.

CITATION LIST

Patent Literature(s)

Patent Literature 1: JP 2007-294261 APatent Literature 2: JP 2013-157552 APatent Literature 3: JP 2019-161218 A

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

An object of the invention is to provide an organic electroluminescence device configured to emit light with a high luminous efficiency and a long lifetime, and an electronic device including the organic electroluminescence device.

Means for Solving the Problem(s)

According to an aspect of the invention, an organic electroluminescence device includes: an anode; a cathode; a first emitting layer and a second emitting layer interposed between the anode and the cathode, the first and second emitting layers being in a direct contact with each other, and a first electron transporting layer between the first and second emitting layers being in a direct contact with each other and the cathode, in which the first emitting layer comprises a first compound represented by a formula (1) below as a first host material, the first compound comprises at least one group represented by a formula (11) below, the second emitting layer comprises a second compound represented by a formula (2) below as a second host material, and the first electron transporting layer comprises a third compound represented by a formula (3) below.



In the formula (1): R101to R110are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a group represented by —Si(R901)(R902)(R903), a group represented by —O—(R904), a group represented by —S—(R905), a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a group represented by —C(═O)R801, a group represented by —COOR802, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms, or a group represented by a formula (11) above.

At least one of R101to R110is the group represented by the formula (11).

When a plurality of groups represented by the formula (11) are present, the plurality of groups represented by the formula (11) are mutually the same or different.

L101is a single bond, a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted divalent heterocyclic group having 5 to 50 ring atoms.

Ar101is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.

mx is 0, 1, 2, 3, 4 or 5.

When two or more L101are present, two or more L101are mutually the same or different.

When two or more Ar101are present, two or more Ar101are mutually the same or different.

A mark * in the formula (11) represents a bonding position to a pyrene ring in the formula (1).



In the formula (2): R201to R208are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a group represented by —Si(R901)(R902)(R903), a group represented by —O—(R904), a group represented by —S—(R905), a group represented by —N(R906)(R907), a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a group represented by —C(═O)R801, a group represented by —COOR802, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;

L201and L202are each independently a single bond, a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted divalent heterocyclic group having 5 to 50 ring atoms; and

Ar201and Ar202are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.



In the formula (3): A is a substituted or unsubstituted aryl group having 6 to 18 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 13 ring atoms;

B is a substituted or unsubstituted aryl group having 6 to 18 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 13 ring atoms;

L is a single bond, a substituted or unsubstituted (n+1)-valent aromatic hydrocarbon ring group having 6 to 18 ring carbon atoms, a substituted or unsubstituted (n+1)-valent heterocyclic group having 5 to 13 ring atoms, or a (n+1)-valent group having a structure in which two or three different groups selected from the group consisting of a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 18 ring carbon atoms and a substituted or unsubstituted heterocyclic group having 5 to 13 ring atoms are bonded to each other;

C is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 60 ring atoms;

n is 1, 2 or 3;

when n is 2 or more, L is not a single bond; and

when n is 2 or more, a plurality of C are mutually the same or different.

In the first compound represented by the formula (1) and the second compound represented by the formula (2): R901, R902, R903, R904, R905, R906, R907, R801and R802are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms;

when a plurality of R901are present, the plurality of R901are mutually the same or different;

when a plurality of R902are present, the plurality of R902are mutually the same or different;

when a plurality of R903are present, the plurality of R903are mutually the same or different;

when a plurality of R904are present, the plurality of R904are mutually the same or different;

when a plurality of R905are present, the plurality of R905are mutually the same or different;

when a plurality of R906are present, the plurality of R906are mutually the same or different;

when a plurality of R907are present, the plurality of R907are mutually the same or different;

when a plurality of R801are present, the plurality of R801are mutually the same or different; and

when a plurality of R802are present, the plurality of R802are mutually the same or different.

According to another aspect of the invention, an organic electroluminescence device includes: an anode; a cathode; a first emitting layer and a second emitting layer interposed between the anode and the cathode, the first and second emitting layers being in a direct contact with each other; and a first electron transporting layer between the first and second emitting layers being in a direct contact with each other and the cathode, in which the first emitting layer comprises a first compound as a first host material, the second emitting layer comprises a second compound as a second host material, the first host material and the second host material are different from each other, the first emitting layer at least comprises a compound that emits light having a maximum peak wavelength of 500 nm or less, the second emitting layer at least comprises a compound that emits light having a maximum peak wavelength of 500 nm or less, the compound that is contained in the first emitting layer and emits light having the maximum peak wavelength of 500 nm or less and the compound that is contained in the second emitting layer and emits light having the maximum peak wavelength of 500 nm or less are mutually the same or different, a triplet energy T1(H1) of the first host material and a triplet energy T1(H2) of the second host material satisfy a numerical formula below (Numerical Formula 1A), and the first electron transporting layer comprises a third compound represented by a formula (3) below,
T1(H1)>T1(H2)  (Numerical Formula 1A).

According to still another aspect of the invention, an electronic device including the organic electroluminescence device according to the above aspect of the invention is provided.

According to the above aspect of the invention, an organic electroluminescence device having a high luminous efficiency and a long lifetime can be provided. According to the aspect of the invention, an electronic device including the organic electroluminescence device can be provided.

