JPWO2014122933A1 - Organic electroluminescence device - Google Patents

Abstract

A first light emitting unit disposed above the first electrode and having a first light emitting layer and an electron transport layer; a charge generating layer disposed above the first light emitting unit; and the charge generation A second light emitting unit disposed above the layer and having a second light emitting layer; and a second electrode disposed above the second light emitting unit, wherein the charge generation layer is on the first electrode side The organic electroluminescent element which has the N layer arrange | positioned in P and the P layer arrange | positioned at the said 2nd electrode side, and the electron carrying layer of a said 1st light emission unit contains the compound represented by following formula (1).

Description

  The present invention relates to an organic electroluminescence (EL) element.

  As an element configuration of the organic EL element, there is a configuration (MPE element) in which a plurality of light emitting units composed of an organic layer having at least a light emitting layer are stacked with an insulating charge generation layer interposed between an anode and a cathode. Are known.

  Examples of organic EL elements in which a plurality of light emitting units are stacked include Patent Document 1 and Patent Document 2. In Patent Document 1, a monochromatic stack type element is obtained by stacking light emitting units having a single emission color. In Patent Document 2, a white stack type element is obtained by stacking light emitting units having a plurality of light emitting colors, and a light emitting layer having long wavelength light emission is arranged close to the anode. However, the white light emitting element has a problem in that the chromaticity is shifted because the luminous efficiency of each light emitting layer behaves differently depending on the current density.

JP 2006-173550 A JP 2010-129301 A

  An object of the present invention is to provide a stack type organic electroluminescence device having a small chromaticity shift even at a low current density.

  As a result of diligent research, the present inventors have found that by using a specific compound for the light emitting unit in contact with the anode, a stack type organic electroluminescence device having a small chromaticity shift can be obtained even at a low current, The present invention has been completed.

（前記式（１）において、
Ｘ^１〜Ｘ^６は、それぞれ独立に、窒素原子又はＣＲである。但し、Ｘ^１〜Ｘ^６のうち１から４つは窒素原子である。
Ｒは、それぞれ独立に、水素原子、ハロゲン原子、シアノ基、ニトロ基、ヒドロキシル基、カルボキシル基、スルホニル基、メルカプト基、置換若しくは無置換のボリル基、置換若しくは無置換のホスフィノ基、置換若しくは無置換のアシル基、置換若しくは無置換のアミノ基、置換若しくは無置換のシリル基、置換若しくは無置換の炭素数１〜３０のアルキル基、置換若しくは無置換の炭素数２〜３０のアルケニル基、置換若しくは無置換の炭素数２〜３０のアルキニル基、置換若しくは無置換の炭素数６〜３０のアラルキル基、置換若しくは無置換の炭素数１〜３０のアルコキシ基、置換若しくは無置換の環形成炭素数６〜４０のアリールオキシ基、置換若しくは無置換の環形成炭素数５〜４０のヘテロアリールオキシ基、置換若しくは無置換の炭素数１〜３０のアルキルチオ基、置換若しくは無置換の環形成炭素数６〜４０のアリールチオ基、置換若しくは無置換の環形成炭素数５〜４０のヘテロアリールチオ基、置換若しくは無置換の炭素数２〜３０のアルコキシカルボニル基、置換若しくは無置換の環形成炭素数６〜４０のアリールオキシカルボニル基、置換若しくは無置換の環形成炭素数５〜４０のヘテロアリールオキシカルボニル基、置換若しくは無置換の環形成炭素数６〜４０の芳香族炭化水素基、置換若しくは無置換の環形成原子数５〜４０の複素環基からなる群から選ばれる基である。前記置換基同士は環を形成していてもよい。）According to one form of this invention, the following organic electroluminescent elements are provided.
A first light emitting unit disposed above the first electrode and having a first light emitting layer and an electron transport layer; a charge generating layer disposed above the first light emitting unit; and the charge generation A second light emitting unit disposed above the layer and having a second light emitting layer; and a second electrode disposed above the second light emitting unit, wherein the charge generation layer is on the first electrode side The organic electroluminescent element which has the N layer arrange | positioned in P and the P layer arrange | positioned at the said 2nd electrode side, and the electron carrying layer of a said 1st light emission unit contains the compound represented by following formula (1).

(In the above formula (1),
X ^{1 to} X ⁶ are each independently a nitrogen atom or CR. However, 1 to 4 of X ^{1 to} X ⁶ are nitrogen atoms.
Each R is independently a hydrogen atom, halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, sulfonyl group, mercapto group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphino group, substituted or unsubstituted Substituted acyl group, substituted or unsubstituted amino group, substituted or unsubstituted silyl group, substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, substituted Or an unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted ring forming carbon number An aryloxy group having 6 to 40, a substituted or unsubstituted heteroaryloxy group having 5 to 40 ring carbon atoms, substituted or unsubstituted, Substituted alkylthio groups having 1 to 30 carbon atoms, substituted or unsubstituted arylthio groups having 6 to 40 ring carbon atoms, substituted or unsubstituted heteroarylthio groups having 5 to 40 ring carbon atoms, substituted or unsubstituted An alkoxycarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryloxycarbonyl group having 6 to 40 ring carbon atoms, a substituted or unsubstituted heteroaryloxycarbonyl group having 5 to 40 ring carbon atoms, substituted or unsubstituted It is a group selected from the group consisting of a substituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms and a substituted or unsubstituted heterocyclic group having 5 to 40 ring atoms. The substituents may form a ring. )

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a low current density, it can provide that a stack type organic electroluminescent element with a small chromaticity shift can be obtained.

It is a schematic sectional drawing which shows one Embodiment of the organic EL element which concerns on one form of this invention. It is a schematic sectional drawing which shows other embodiment of the organic EL element which concerns on one form of this invention. It is the schematic which shows the example which formed three organic EL elements on the board | substrate. It is a schematic sectional drawing of the color display apparatus using the organic EL element of one form of this invention.

An organic EL device according to an aspect of the present invention is disposed above a first electrode, a first light emitting unit that is disposed above the first electrode, and includes a first light emitting layer and an electron transport layer, and the first light emitting unit. And a second light emitting unit disposed above the charge generating layer and having a second light emitting layer, and a second electrode disposed above the second light emitting unit.
The charge generation layer has an N layer disposed on the first electrode side and a P layer disposed on the second electrode side.
Here, “upper” includes both the case of contact and the case of non-contact. For example, the first light-emitting unit disposed above the first electrode has a case where the first light-emitting unit is in contact with the first electrode. And a case where another layer is interposed between the first electrode and the first light emitting unit.

  FIG. 1 is a schematic cross-sectional view of one embodiment of an organic EL device according to one embodiment of the present invention. The organic EL element 1 includes an anode 20, a first light emitting unit 30A, a charge generation layer 40, a second light emitting unit 30B, and a cathode 50 on a substrate 10 in this order.

  The first light emitting unit 30A and the second light emitting unit 30B emit light by recombination of electrons and holes. Each of the two light emitting units has a single layer or a stacked structure having at least light emitting layers 32A and 32B. In this embodiment, the light emitting unit has a multilayer structure in which a hole transport layer 31, a light emitting layer 32, and an electron transport layer 33 are stacked from the anode side.

  The charge generation layer 40 generates holes and electrons when a voltage is applied, and injects holes into the light emitting unit disposed on the cathode 50 side of the charge generation layer 40, that is, the second light emitting unit 30B. This layer serves to inject electrons into the light emitting unit disposed on the anode 20 side of the charge generation layer 40, that is, the first light emitting unit 30A.

（式（１）において、
Ｘ^１〜Ｘ^６は、それぞれ独立に、窒素原子、又はＣＲである。但し、Ｘ^１〜Ｘ^６のうち少なくとも１つは窒素原子である。
Ｒは、それぞれ独立に、水素原子、ハロゲン原子、シアノ基、ニトロ基、ヒドロキシル基、カルボキシル基、スルホニル基、メルカプト基、置換若しくは無置換のボリル基、置換若しくは無置換のホスフィノ基、置換若しくは無置換のアシル基、置換若しくは無置換のアミノ基、置換若しくは無置換のシリル基、置換若しくは無置換の炭素数１〜３０のアルキル基、置換若しくは無置換の炭素数２〜３０のアルケニル基、置換若しくは無置換の炭素数２〜３０のアルキニル基、置換若しくは無置換の炭素数６〜３０のアラルキル基、置換若しくは無置換の炭素数１〜３０のアルコキシ基、置換若しくは無置換の環形成炭素数６〜４０のアリールオキシ基、置換若しくは無置換の環形成炭素数５〜４０のヘテロアリールオキシ基、置換若しくは無置換の炭素数１〜３０のアルキルチオ基、置換若しくは無置換の環形成炭素数６〜４０のアリールチオ基、置換若しくは無置換の環形成炭素数５〜４０のヘテロアリールチオ基、置換若しくは無置換の炭素数２〜３０のアルコキシカルボニル基、置換若しくは無置換の環形成炭素数６〜４０のアリールオキシカルボニル基、置換若しくは無置換の環形成炭素数５〜４０のヘテロアリールオキシカルボニル基、置換若しくは無置換の環形成炭素数６〜４０の芳香族炭化水素基、及び置換若しくは無置換の環形成原子数５〜４０の複素環基からなる群から選ばれる基である。前記置換基同士は環を形成していてもよい。）In the organic EL device according to one embodiment of the present invention, the electron transport layer of the first light emitting unit (for example, the electron transport layer 33 of the first light emitting unit 30A) includes a compound represented by the following formula (1).

(In Formula (1),
X ^{1 to} X ⁶ are each independently a nitrogen atom or CR. However, at least one of X ^{1 to} X ⁶ is a nitrogen atom.
Each R is independently a hydrogen atom, halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, sulfonyl group, mercapto group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphino group, substituted or unsubstituted Substituted acyl group, substituted or unsubstituted amino group, substituted or unsubstituted silyl group, substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, substituted Or an unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted ring forming carbon number An aryloxy group having 6 to 40, a substituted or unsubstituted heteroaryloxy group having 5 to 40 ring carbon atoms, substituted or unsubstituted, Substituted alkylthio groups having 1 to 30 carbon atoms, substituted or unsubstituted arylthio groups having 6 to 40 ring carbon atoms, substituted or unsubstituted heteroarylthio groups having 5 to 40 ring carbon atoms, substituted or unsubstituted An alkoxycarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryloxycarbonyl group having 6 to 40 ring carbon atoms, a substituted or unsubstituted heteroaryloxycarbonyl group having 5 to 40 ring carbon atoms, substituted or unsubstituted It is a group selected from the group consisting of a substituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms and a substituted or unsubstituted heterocyclic group having 5 to 40 ring atoms. The substituents may form a ring. )

  When the electron transport layer of the first light emitting unit contains the compound represented by the formula (1), it is possible to confine exciton energy in the light emitting layer while injecting strong holes into the light emitting layer in the first light emitting unit. Can prevent chromaticity deviation.

（式（２）において、
Ｘ^１〜Ｘ^６は、それぞれ独立に、窒素原子、ＣＲ又はＣＷである。
但し、Ｘ^１〜Ｘ^６のうち少なくとも１つは窒素原子であり、Ｘ^１〜Ｘ^６のうち少なくとも１つはＣＷである。
Ｒは、式（１）のＲと同じである。
Ｗは、下記式（１１）で表される基である。
尚、Ｗは、Ｘ^１〜Ｘ^６のいずれかの炭素原子に結合する。）

（式（１１）において、
ａは、１以上５以下の整数である。ａが２以上５以下のとき、Ａｒ^１は、互いに同一又は異なる。
Ｌ^１は、単結合又は連結基であり、Ｌ^１における連結基は、置換若しくは無置換の炭素数１〜３０の直鎖状、分岐鎖状若しくは環状の多価の脂肪族炭化水素基、置換若しくは無置換の多価のアミノ基、置換若しくは無置換の環形成炭素数６〜４０の多価の芳香族炭化水素環基、置換若しくは無置換の環形成原子数５〜４０の多価の複素環基、又は前記芳香族炭化水素環基及び前記複素環基から選ばれる２〜３個の基が結合してなる多価の多重連結基である。
尚、前記多重連結基において、前記多重連結基を構成する前記芳香族炭化水素環基及び前記複素環基は、互いに同一又は異なり、隣り合う前記芳香族炭化水素環基及び前記複素環基は環を形成していてもよい。
Ａｒ^１は、置換若しくは無置換の環形成炭素数６〜４０の芳香族炭化水素基、又は置換若しくは無置換の環形成原子数５〜４０の複素環基である。但し、Ａｒ^１の少なくとも１つは下記式（２１）で表わされる基である。
Ａｒ^１とＬ^１は、環構造を形成する場合と、形成しない場合とがある。）

（式（２１）中、
Ｘは、ＮＲ、Ｃ（Ｒ）_２、酸素原子又は硫黄原子である。
Ｘ^７〜Ｘ^１４は、それぞれ独立に、窒素原子、又はＣＲである。
Ｒは、式（１）と同じである。
但し、式（２１）中の結合手は、前記式（１１）中のＬ^１に結合する結合手を意味し、Ｘ及びＸ^７〜Ｘ^１４の少なくとも１つ、好ましくは１つに結合する。）The compound represented by the formula (1) is preferably a compound represented by the following formula (2).

(In Formula (2),
X ^{1 to} X ⁶ are each independently a nitrogen atom, CR or CW.
However, at least one of X ^{1 to} X ⁶ is a nitrogen atom, and at least one of X ^{1 to} X ⁶ is CW.
R is the same as R in formula (1).
W is a group represented by the following formula (11).
^Note, W is bound to any carbon atom of X 1 to X ^6. )

(In Formula (11),
a is an integer of 1 to 5. When a is 2 or more and 5 or less, Ar ¹ is the same or different from each other.
L ¹ is a single bond or a linking group, and the linking group in L ¹ is a substituted or unsubstituted C 1-30 linear, branched or cyclic polyvalent aliphatic hydrocarbon group, substituted Or an unsubstituted polyvalent amino group, a substituted or unsubstituted polyvalent aromatic hydrocarbon ring group having 6 to 40 ring carbon atoms, a substituted or unsubstituted polyvalent complex having 5 to 40 ring atoms. It is a polyvalent multiple linking group formed by bonding a cyclic group, or two or three groups selected from the aromatic hydrocarbon cyclic group and the heterocyclic group.
In the multiple linking group, the aromatic hydrocarbon ring group and the heterocyclic group constituting the multiple linking group are the same or different from each other, and the adjacent aromatic hydrocarbon ring group and the heterocyclic group are cyclic. May be formed.
Ar ¹ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 40 ring atoms. However, at least one of Ar ¹ is a group represented by the following formula (21).
Ar ¹ and L ¹ may or may not form a ring structure. )

(In Formula (21),
X is NR, C (R) ₂ , an oxygen atom or a sulfur atom.
X ^{7 to} X ¹⁴ are each independently a nitrogen atom or CR.
R is the same as in formula (1).
However, the bond in the formula (21) means a bond bonded to L ¹ in the formula (11), and bonds to at least one of X and X ^{7 to} X ¹⁴ , preferably one. )

In formulas (1) and (2), X ¹ and X ³ are preferably nitrogen atoms, more preferably X ¹ and X ³ are nitrogen atoms, X ⁵ is CH, and X ² is CR ¹¹ X ⁴ is CR ¹² and X ⁶ is a group represented by the formula (11).
R ¹¹ and R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms, or a substituted or unsubstituted heterocyclic ring having 5 to 40 ring atoms. It is a group.

In the formulas (1) and (2), X ¹ , X ³ and X ⁵ are preferably nitrogen atoms, more preferably X ¹ , X ³ and X ⁵ are nitrogen atoms, and X ² is CR ¹¹ , X ⁴ is CR ¹² , and X ⁶ is a group represented by the formula (11).
R ¹¹ and R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms, or a substituted or unsubstituted heterocyclic ring having 5 to 40 ring atoms. It is a group.

In the formulas (1) and (2), X ¹ and X ⁵ are preferably nitrogen atoms, X ³ is CH, X ² is CR ¹¹ , X ⁴ is CR ¹² , and X ⁶ is the above-mentioned It is group represented by Formula (11).
R ¹¹ and R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms, or a substituted or unsubstituted heterocyclic ring having 5 to 40 ring atoms. It is a group.

L ^{1 in} formula (11) is preferably a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 40 ring carbon atoms, or a substituted or unsubstituted trivalent ring having 6 to 40 ring carbon atoms. It is an aromatic hydrocarbon group.
The aromatic hydrocarbon group of L ¹ is preferably a divalent or trivalent group corresponding to a phenyl group.

X in formula (21) is preferably NR or an oxygen atom.
X in formula (21) is preferably X is NR, and R is linked to L ¹ .

  A in formula (11) is preferably 1 or 2.

（式（１１−１）中、Ｌ^１は前記式（１１）のＬ^１と同じである。
ｎは、それぞれ独立に、０〜４の整数であり、Ｒ’は、それぞれ独立に、置換若しくは無置換の炭素数１〜３０のアルキル基、置換若しくは無置換の炭素数２〜３０のアルケニル基、置換若しくは無置換の炭素数２〜３０のアルキニル基、置換若しくは無置換の炭素数６〜３０のアラルキル基、置換若しくは無置換の環形成炭素数６〜２０のアリールオキシ基、置換若しくは無置換の環形成炭素数６〜２０のアリールチオ基、置換若しくは無置換の環形成炭素数６〜２０の芳香族炭化水素基、及び置換若しくは無置換の環形成原子数５〜２０の複素環基からなる群から選ばれる基である。前記置換基同士は環を形成していてもよい。）

（式（１１−２）中、Ｌ^１は前記式（１１）のＬ^１と同じである。
ｎは、それぞれ独立に、０〜４の整数であり、Ｒ’は、それぞれ独立に、置換若しくは無置換の炭素数１〜３０のアルキル基、置換若しくは無置換の炭素数２〜３０のアルケニル基、置換若しくは無置換の炭素数２〜３０のアルキニル基、置換若しくは無置換の炭素数６〜３０のアラルキル基、置換若しくは無置換の環形成炭素数６〜２０のアリールオキシ基、置換若しくは無置換の環形成炭素数６〜２０のアリールチオ基、置換若しくは無置換の環形成炭素数６〜２０の芳香族炭化水素基、及び置換若しくは無置換の環形成原子数５〜２０の複素環基からなる群から選ばれる基である。前記置換基同士は環を形成していてもよい。）The group represented by the formula (11) is preferably a group represented by the following formula (11-1) or the following formula (11-2).

(In Formula (11-1), L ¹ is the same as L ^{1 in} Formula (11).
n is each independently an integer of 0 to 4, and R ′ is independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms. Substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, substituted or unsubstituted aralkyl group having 6 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms, substituted or unsubstituted And an arylthio group having 6 to 20 ring carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 20 ring atoms. It is a group selected from the group. The substituents may form a ring. )

(In Formula (11-2), L ¹ is the same as L ^{1 in} Formula (11).
n is each independently an integer of 0 to 4, and R ′ is independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms. Substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, substituted or unsubstituted aralkyl group having 6 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms, substituted or unsubstituted And an arylthio group having 6 to 20 ring carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 20 ring atoms. It is a group selected from the group. The substituents may form a ring. )

  In the above formulas (11-1) and (11-2), when there are a plurality of R ′, the plurality of R ′ may be the same as or different from each other.

（式中、Ｘ^２、Ｘ^５及びＸ^６は、前記式（１）のＸ^２、Ｘ^５及びＸ^６とそれぞれ同じである。
Ａｒ^１、Ｌ^１及びａは、前記式（１１）のＡｒ^１、Ｌ^１及びａとそれぞれ同じである。
Ｂは以下から一つ選択される基である。以下に記載した基の結合手のそれぞれは、前記式（１１−３）中の炭素原子とＢとを連結する結合手を意味し、選択される基を構成する任意の炭素原子と結合する（但し、水素原子と結合できない炭素原子を除く）。

The compound represented by the formula (1) is preferably a compound represented by the following formula (11-3).

(Wherein X ² , X ⁵ and X ⁶ are the same as X ² , X ⁵ and X ⁶ in the formula (1), respectively.
Ar ^{1, L 1} and a are respectively the same as ^Ar 1, ^{L 1} and a in the formula (11).
B is a group selected from the following. Each of the bond hands of the group described below means a bond linking the carbon atom in formula (11-3) and B, and is bonded to any carbon atom constituting the selected group ( However, carbon atoms that cannot be bonded to hydrogen atoms are excluded).

  In the present specification, the aryl group includes a monocyclic aromatic hydrocarbon ring group and a condensed aromatic hydrocarbon ring group in which a plurality of hydrocarbon rings are condensed, and the heteroaryl group is a monocyclic heteroaromatic group. And a hetero-fused aromatic ring group in which a plurality of heteroaromatic rings are condensed, and a hetero-fused aromatic ring group in which an aromatic hydrocarbon ring and a heteroaromatic ring are condensed.

  In this specification, the number of ring-forming carbon atoms constitutes the ring itself of a compound having a structure in which atoms are bonded cyclically (for example, a monocyclic compound, a condensed ring compound, a bridged compound, a carbocyclic compound, or a heterocyclic compound). Represents the number of carbon atoms in the atom. When the ring is substituted with a substituent, the carbon contained in the substituent is not included in the number of ring-forming carbons. The “ring-forming carbon number” described below is the same unless otherwise specified. For example, the benzene ring has 6 ring carbon atoms, the naphthalene ring has 10 ring carbon atoms, the pyridinyl group has 5 ring carbon atoms, and the furanyl group has 4 ring carbon atoms. Further, when an alkyl group is substituted as a substituent on the benzene ring or naphthalene ring, the carbon number of the alkyl group is not included in the number of ring-forming carbons. In addition, for example, when a fluorene ring is bonded to the fluorene ring as a substituent (including a spirofluorene ring), the carbon number of the fluorene ring as a substituent is not included in the number of ring-forming carbons.

  In this specification, the number of ring-forming atoms means a compound (for example, a monocyclic compound, a condensed ring compound, a bridging compound, a carbocyclic compound, a heterocyclic compound) having a structure in which atoms are bonded in a cyclic manner (for example, a monocyclic ring, a condensed ring, or a ring assembly). Of the ring compound) represents the number of atoms constituting the ring itself. An atom that does not constitute a ring (for example, a hydrogen atom that terminates a bond of an atom that constitutes a ring) or an atom contained in a substituent when the ring is substituted by a substituent is not included in the number of ring-forming atoms. The “number of ring-forming atoms” described below is the same unless otherwise specified. For example, the pyridine ring has 6 ring atoms, the quinazoline ring has 10 ring atoms, and the furan ring has 5 ring atoms. A hydrogen atom bonded to a carbon atom of a pyridine ring or a quinazoline ring or an atom constituting a substituent is not included in the number of ring-forming atoms. Further, when, for example, a fluorene ring is bonded to the fluorene ring as a substituent (including a spirofluorene ring), the number of atoms of the fluorene ring as a substituent is not included in the number of ring-forming atoms.

  In the present specification, the “carbon number XX to YY” in the expression “substituted or unsubstituted ZZ group having XX to YY” represents the number of carbon atoms in the case where the ZZ group is unsubstituted. The carbon number of the substituent in the case where it is present is not included. Here, “YY” is larger than “XX”, and “XX” and “YY” each mean an integer of 1 or more.

  In the present specification, “atom number XX to YY” in the expression “a ZZ group having a substituted or unsubstituted atom number XX to YY” represents the number of atoms when the ZZ group is unsubstituted, In this case, the number of substituent atoms is not included. Here, “YY” is larger than “XX”, and “XX” and “YY” each mean an integer of 1 or more.

  The term “unsubstituted” in the case of “substituted or unsubstituted” means that a hydrogen atom is bonded without being substituted with the substituent. The hydrogen atom includes isotopes having different numbers of neutrons, that is, light hydrogen (protium), deuterium (deuterium), and tritium.

As the substituent in the above “substituted or unsubstituted...”, A halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, sulfonyl group, mercapto group, boryl group, phosphino group, acyl group, amino group, Silyl group, alkyl group having 1 to 30 carbon atoms, alkenyl group having 2 to 30 carbon atoms, alkynyl group having 2 to 30 carbon atoms, aralkyl group having 6 to 30 carbon atoms, alkoxy group having 1 to 30 carbon atoms, ring formation Aryloxy group having 6 to 40 carbon atoms, heteroaryloxy group having 5 to 40 ring carbon atoms, alkylthio group having 1 to 30 carbon atoms, arylthio group having 6 to 40 ring carbon atoms, and 5 to 40 ring carbon atoms Heteroarylthio groups, alkoxycarbonyl groups having 2 to 30 carbon atoms, aryloxycarbonyl groups having 6 to 40 ring carbon atoms, and 5 to 40 ring carbon atoms Hetero aryloxycarbonyl group, an aromatic hydrocarbon group having 6 to 40 ring carbon atoms, and heterocyclic groups such as ring atoms 5 to 40 and the like.
These substituents may be further substituted with the above substituents. A plurality of these substituents may be bonded to each other to form a ring.

Specific examples of each group in the above formula are listed below.
As a halogen atom, a fluorine atom, a chlorine atom, and a bromine atom are mentioned, Preferably it is a fluorine atom.
Examples of the amino group include alkylamino, arylamino and alkylarylamino. Examples of the alkyl group and aryl group bonded to the nitrogen atom include an aryl group and an alkyl group described later.
Examples of the silyl group include alkylsilyl, arylsilyl and alkylarylsilyl. Examples of the alkyl group and aryl group bonded to the silicon atom include an aryl group and an alkyl group described later.

The alkyl group having 1 to 30 carbon atoms includes a linear or branched alkyl group, preferably 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms. For example, methyl, ethyl, propyl, butyl, pentyl, hexyl and the like can be mentioned.
Examples of the linear, branched or cyclic polyvalent aliphatic hydrocarbon group having 1 to 30 carbon atoms include polyvalent groups corresponding to the above alkyl groups.
Examples of the alkenyl group or alkynyl group having 2 to 30 carbon atoms include a substituent having an unsaturated bond in the molecule of the alkyl group described above.
An aralkyl group having 6 to 30 carbon atoms (preferably 7 to 30 carbon atoms) is represented as -Y-Z, and examples of Y include alkylene examples corresponding to the above alkyl group examples. Examples of the aryl group described below are mentioned. The aryl part of the aralkyl group preferably has 6 to 30 carbon atoms. The alkyl moiety preferably has 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms.

A C1-C30 alkoxy group is represented as -OY and the example of said alkyl group is mentioned as an example of Y. The alkoxy group preferably has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, and examples thereof include methoxy, ethoxy, propoxy, butoxy and the like.
The aryloxy group having 6 to 40 ring carbon atoms is represented as -OY, and examples of Y include the examples of aryl groups described later. Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12, for example, phenyloxy, 2-naphthyloxy, etc. are mentioned.
A heteroaryloxy group having 5 to 40 ring carbon atoms is represented as -OY, and examples of Y include examples of heteroaryl groups described later. The heteroaryloxy group preferably has 5 to 40 ring atoms.

A C1-C30 alkylthio group is represented as -SY and the example of said alkyl group is mentioned as an example of Y. Preferably it is C1-C20, More preferably, it is C1-C12, Most preferably, it is C1-C8.
The arylthio group having 6 to 40 ring carbon atoms is represented by -SY, and examples of Y include examples of aryl groups described later. Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12, for example, phenylthio etc. are mentioned.
The heteroarylthio group having 5 to 40 ring carbon atoms is represented as -SY, and examples of Y include the examples of heteroaryl groups described later. The heteroarylthio group preferably has 5 to 40 ring atoms.

The alkoxycarbonyl group having 2 to 30 carbon atoms is a group consisting of the above alkyl group, oxygen atom and carbonyl group, preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 carbon atoms. -12, for example, methoxycarbonyl, ethoxycarbonyl and the like.
The aryloxycarbonyl group having 6 to 40 ring carbon atoms is a group composed of an alkyl group, an oxygen atom and a carbonyl group, which will be described later, preferably 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably. It has 6 to 12 carbon atoms.
The heteroaryloxycarbonyl group having 5 to 40 ring carbon atoms is a group consisting of a heteroaryl group, an oxygen atom and a carbonyl group described later. The heteroaryloxycarbonyl group preferably has 5 to 40 ring atoms.

The aromatic hydrocarbon group (aryl group) having 6 to 40 ring carbon atoms preferably has 6 to 20 ring carbon atoms, and includes phenyl group, tolyl group, xylyl group, naphthyl group, phenanthryl group, pyrenyl group, chrysenyl group. Group, benzo [c] phenanthryl group, benzo [g] chrysenyl group, benzoanthryl group, triphenylenyl group, fluorenyl group, 9,9-dimethylfluorenyl group, benzofluorenyl group, dibenzofluorenyl group, biphenyl Group, terphenyl group, fluoranthenyl group and the like, and phenyl group, biphenyl group and naphthyl group are preferable.
Examples of the polyvalent aromatic hydrocarbon ring group having 6 to 40 ring carbon atoms include polyvalent groups corresponding to the aryl group.

The heterocyclic group (heteroaryl group) having 5 to 40 ring atoms is preferably 5 to 20 ring atoms, and is a pyrrolyl group, pyrazolyl group, pyrazinyl group, pyrimidinyl group, pyridazinyl group, pyridyl group, triazinyl group. , Indolyl group, isoindolyl group, imidazolyl group, benzimidazolyl group, indazolyl group, imidazo [1,2-a] pyridinyl group, furyl group, benzofuranyl group, isobenzofuranyl group, dibenzofuranyl group, azadibenzofuranyl group Thiophenyl group, benzothiophenyl group, dibenzothiophenyl group, azadibenzothiophenyl group, quinolyl group, isoquinolyl group, quinoxalinyl group, quinazolinyl group, naphthyridinyl group, carbazolyl group, azacarbazolyl group, phenanthridinyl group, acridinyl group, Phenanthrolinyl , Phenazinyl group, phenothiazinyl group, phenoxazinyl group, oxazolyl group, oxadiazolyl group, furazanyl group, benzoxazolyl group, thienyl group, thiazolyl group, thiadiazolyl group, benzthiazolyl group, triazolyl group, tetrazolyl group, preferably A dibenzofuranyl group, a dibenzothiophenyl group, and a carbazolyl group.
Examples of the polyvalent heterocyclic group having 5 to 40 ring atoms include a polyvalent group corresponding to the heteroaryl group.

  The compound represented by the formula (1) has a triplet energy of 2.5 to 3.3 eV, and preferably 2.5 to 3.2 eV. The compound represented by the formula (1) has a singlet energy of 2.8 to 3.8 eV, and preferably 2.9 to 3.7 eV.

  Singlet energy was measured from the absorption edge of the absorption spectrum in benzene. Specifically, the absorption spectrum can be measured using a commercially available visible / ultraviolet spectrophotometer, and can be calculated from the wavelength at which the spectrum starts to rise.

The triplet energy (E ^T ) can be measured using, for example, a commercially available apparatus F-4500 (manufactured by Hitachi). Conversion formula of E ^T is as follows.
Conversion formula: E ^T (eV) = 1239.85 / λedge
In the formula, “λedge” means that when the phosphorescence spectrum is represented by taking the phosphorescence intensity on the vertical axis and the wavelength on the horizontal axis, a tangent line is drawn with respect to the rising edge on the short wavelength side of the phosphorescence spectrum. It means the wavelength value at the intersection of axes (unit: nm).
Further, the triplet energy E ^T may be determined by quantum chemical calculation below.
Quantum chemical calculations can be performed using Gaussian 03, a quantum chemical calculation program manufactured by Gaussian. Gaussian03 is a program developed by JAPople et al., Which won the Nobel Prize in Chemistry in 1998. For various molecular systems, physical properties such as molecular energy, structure, and normal vibration can be obtained by various quantum chemical calculation methods. It is possible to predict. For the calculation, density functional theory (DFT) is used. For the structure optimized using B3LYP as the functional and 6-31G * as the basis function, the calculated triplet energy can be obtained by time-dependent density functional theory (TD-DFT).
In some organic compounds, the phosphorescence spectrum may not be observed. Such in organic compounds, to the use of triplet energy E ^T obtained by using a quantum chemical calculation, as indicated above in estimation.

Specific examples of the compound represented by the formula (1) are shown below. However, the compound represented by Formula (1) is not limited to the following specific example.

(Light emitting unit)
The light emitting unit has a single layer or a stacked structure including at least a light emitting layer. The light-emitting unit preferably has a multilayer film structure composed of a first organic layer, a light-emitting layer, and a second organic layer from the anode side. Examples include a membrane structure.
The hole transport zone is configured by laminating a single layer or a plurality of hole injection layers and hole transport layers. The electron transport zone is configured by laminating a single layer or a plurality of electron injection layers and electron transport layers.

The first light emitting unit preferably includes a first electrode, a hole transport layer in contact with the first electrode, a first light emitting layer in contact with the hole transport layer, and an electron transport layer in contact with the first light emitting layer in this order.
The electron transport layer may include a first electron transport layer and a second electron transport layer in this order from the first light emitting layer side. Preferably, the first electron transport layer on the first light emitting layer side is an EEL (Efficiency-enhancement layer). ). The EEL is a layer for suppressing diffusion of triplet excitons generated in the first light emitting layer to the electron transport layer side. The EEL preferably contains a compound represented by the above formula (1). The film thickness of the EEL is preferably 1 nm to 50 nm, particularly preferably 5 nm to 20 nm.

Furthermore, an organic EL device according to one embodiment of the present invention includes a first electrode, a hole transport layer in contact with the first electrode, a first light-emitting layer in contact with the hole transport layer, an electron transport layer in contact with the first light-emitting layer, an electron A charge generation layer in contact with the transport layer;
By arranging each layer as described above, an effect of blocking the exciton energy of light emission by EEL can be obtained.

The organic EL element according to one embodiment of the present invention has two or more light emitting units, but each light emitting unit may be made of the same material, or may be made of different materials.
Further, the layer configuration of each light emitting unit may be the same or different.

The first light emitting unit is preferably a blue light emitting unit having a wavelength band of 430 to 500 nm. In addition, the emission wavelength peak of the first light emitting unit is preferably shorter than the emission wavelength peak of the second light emitting unit.
In the organic EL element according to an embodiment of the present invention, holes are strongly injected into the first light emitting unit, and therefore, the light emitting color of the first light emitting unit is preferably a blue light emitting unit that requires the most energy. For example, in the element 1 shown in FIG. 1, the emission color of the first light emitting unit 30A is blue, and the emission color of the second light emitting unit 30B is yellow. In this case, an organic EL element having two light components mixed to emit white light and little white color deviation can be obtained.
The wavelength band is the peak wavelength of the emission spectrum obtained from the EL emission of each light emitting unit, and the emission when EL light is emitted as a monochromatic EL element without stacking each light emitting unit is measured using a spectroradiometer. .

The organic EL device according to one embodiment of the present invention preferably includes a third light emitting unit disposed above the second light emitting unit, and more preferably, the emission wavelength peak of the first light emitting unit is that of the second light emitting unit. It is shorter than the emission wavelength peak and the emission wavelength peak of the third light emitting unit.
For example, the first light emitting unit is a blue light emitting unit (peak wavelength 430 to 500 nm), the second light emitting unit is a green light emitting unit (peak wavelength 500 to 570 nm), and the third light emitting unit is a red light emitting unit (peak wavelength 570 nm or more). RGB configuration can be adopted.

Hereinafter, the light emitting layer, the hole transport zone, and the electron transport zone constituting the light emitting unit will be described.
(A) Light emitting layer [host material]
The light emitting layer is preferably a layer composed of a host material and a dopant material.
As the host material of the organic EL element, rubrene, anthracene, tetracene, pyrene, perylene and the like can be used, and an anthracene derivative is preferable.
Particularly preferably, the light emitting layer of the light emitting unit in contact with the anode contains an anthracene derivative as a host material. When the host material is an anthracene derivative, the light-emitting layer containing the host can emit blue light, and the light-emitting layer in contact with the anode is a blue light-emitting layer with a short wavelength, which depends on the compound represented by the formula (1). The most benefit of the hole injection effect can be obtained.

（式（３）中、Ｂ_１及びＢ_２は、それぞれ独立に、置換若しくは無置換の環形成炭素数６〜２０の芳香族炭化水素基であり、
Ｒ_１１〜Ｒ_１８は、それぞれ独立に、水素原子、フッ素原子、置換若しくは無置換の炭素数１〜１０のアルキル基、置換若しくは無置換の炭素数３〜１０のシクロアルキル基、置換若しくは無置換の炭素数３〜３０のアルキルシリル基、置換若しくは無置換の環形成炭素数８〜３０のアリールシリル基、置換若しくは無置換の炭素数１〜２０のアルコキシ基、置換若しくは無置換の環形成炭素数６〜２０のアリールオキシ基、置換若しくは無置換の環形成炭素数６〜３０の芳香族炭化水素基、又は置換若しくは無置換の環形成原子数５〜３０の複素環基である。）The anthracene derivative is preferably a compound represented by the following formula (3).

(In Formula (3), B ₁ and B ₂ are each independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms,
R _{11 to} R ₁₈ are each independently a hydrogen atom, a fluorine atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted group. An alkylsilyl group having 3 to 30 carbon atoms, a substituted or unsubstituted arylsilyl group having 8 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted ring forming carbon It is an aryloxy group having 6 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms. )

Examples of the alkyl group include a linear or branched alkyl group. For example, methyl, ethyl, propyl, butyl, pentyl, hexyl and the like can be mentioned.
Examples of the cycloalkyl group include cyclopentyl, cyclohexyl and the like.

The alkoxy group is represented as -OR, and examples of R include the examples of the alkyl group described above. Examples of the alkoxy group include methoxy, ethoxy, propoxy, butoxy and the like.
The aryloxy group is represented as —OAr, and examples of Ar include the examples of the aryl group described above. Examples of the aryloxy group include phenyloxy and 2-naphthyloxy.

The alkylsilyl group is represented as —Si (R ^a ) (R ^b ) (R ^c ), and examples of (R ^a ), (R ^b ) and (R ^c ) include the alkyl groups and hydrogen atoms described above. It is done. Specific examples include a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, and a propyldimethylsilyl group.
The arylsilyl group includes a triarylsilyl group, an alkylarylsilyl group, a trialkylsilyl group, and the like, and examples thereof include a phenyldimethylsilyl group, a methyldiphenylsilyl group, and a triphenylsilyl group.

  Specific examples of the aromatic hydrocarbon group include phenyl, tolyl, xylyl, naphthyl, phenanthryl, pyrenyl, chrysenyl, benzo [c] phenanthryl, benzo [g] chrysenyl, benzoanthryl. , Triphenylenyl group, fluorenyl group, 9,9-dimethylfluorenyl group, benzofluorenyl group, dibenzofluorenyl group, biphenyl group, terphenyl group, fluoranthenyl group, etc., preferably phenyl group, Biphenyl group and naphthyl group.

  Specific examples of the heterocyclic group include pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazol [1, 2-a] pyridinyl group, furyl group, benzofuranyl group, isobenzofuranyl group, dibenzofuranyl group, azadibenzofuranyl group, thiophenyl group, benzothiophenyl group, dibenzothiophenyl group, azadibenzothiophenyl group, quinolyl Group, isoquinolyl group, quinoxalinyl group, quinazolinyl group, naphthyridinyl group, carbazolyl group, azacarbazolyl group, phenanthridinyl group, acridinyl group, phenanthrolinyl group, phenazinyl group, phenothiazinyl group, phenoxazinyl group, oxa Ryl group, oxadiazolyl group, furazanyl group, benzoxazolyl group, thienyl group, thiazolyl group, thiadiazolyl group, benzthiazolyl group, triazolyl group, tetrazolyl group, etc., preferably dibenzofuranyl group, dibenzothiophenyl group, It is a carbazolyl group.

[Dopant material]
Examples of the luminescent dopant include a fluorescent dopant and a phosphorescent dopant.
A fluorescent dopant is a compound that can emit light from singlet excitons. Fluorescent dopants are required from amine compounds, aromatic compounds, chelate complexes such as tris (8-quinolinolato) aluminum complexes, coumarin derivatives, tetraphenylbutadiene derivatives, bisstyrylarylene derivatives, oxadiazole derivatives, and the like. A compound selected according to the emission color is preferable, a styrylamine compound, a styryldiamine compound, an arylamine compound, an aryldiamine compound, and an aromatic compound are more preferable, and a condensed polycyclic amine derivative and an aromatic compound are further preferable. These fluorescent dopants may be used alone or in combination.

As a condensed polycyclic amine derivative, what is represented by following formula (4) is preferable.

In the formula, Y represents a substituted or unsubstituted condensed aryl group having 10 to 50 ring carbon atoms.
Ar ₂₁ and Ar ₂₂ each represent 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.
The condensed aryl group is a group in which two or more ring structures are condensed in the aryl group.
The condensed aryl group is a condensed aryl group having 10 to 50 ring carbon atoms (preferably 10 to 30 ring carbon atoms, more preferably 10 to 20 ring carbon atoms). In the specific examples of the aryl group, Preferred examples include naphthyl group, anthryl group, pyrenyl group, chrysenyl group, phenanthryl group, fluorenyl group, fluoranthenyl group, acenaphthofluoranthenyl group, naphthacenyl group and the like.

Specific examples of Y include the above condensed aryl groups, preferably a substituted or unsubstituted anthryl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted chrysenyl group, or an acenaphthofluoranthenyl group. .
Preferable examples of Ar ₂₁ and Ar ₂₂ include a substituted or unsubstituted phenyl group and a substituted or unsubstituted dibenzofuranyl group. Preferred examples of the substituent for Ar ₂₁ and Ar ₂₂ are an alkyl group, a cyano group, a substituted or unsubstituted silyl group, and a substituted or unsubstituted aryl group. n is an integer of 1-4. n is preferably an integer of 1 to 2.

（式中、Ｘ_１０１〜Ｘ_１０６及びＸ_１０８〜Ｘ_１１１は、それぞれ独立に、水素原子、置換若しくは無置換の環形成炭素数６〜３０のアリール基、置換若しくは無置換の環形成原子数５〜３０の複素環基、置換若しくは無置換の炭素数１〜１０のアルキル基、置換若しくは無置換の環形成炭素数３〜８のシクロアルキル基、置換若しくは無置換の炭素数１〜２０のアルコキシ基、置換若しくは無置換の炭素数７〜５０のアラルキル基、置換若しくは無置換の環形成原子数６〜５０のアリールオキシ基、置換若しくは無置換の環形成原子数５〜５０のアリールチオ基、置換若しくは無置換の炭素数２〜５０のアルコキシカルボニル基、置換若しくは無置換の環形成炭素数６〜３０のアリール基で置換されたアミノ基、ハロゲン原子、シアノ基、ニトロ基、ヒドロキシル基及びカルボキシル基から選ばれる。
Ｘ_１０７及びＸ_１１２は、それぞれ独立に、置換若しくは無置換の環形成炭素数６〜３０のアリール基、置換若しくは無置換の環形成原子数５〜３０の複素環基、置換若しくは無置換の炭素数１〜２０のアルキル基、及び置換若しくは無置換の環形成炭素数３〜８のシクロアルキル基から選ばれる。
但し、Ｘ_１０３とＸ_１０４は、互いに異なる置換基である。
また、Ｘ_１０１〜Ｘ_１１２において、隣接する置換基同士は互いに結合して飽和若しくは不飽和の環状構造を形成してもよく、これら環状構造は置換されてもよい。）As the aromatic compound, a fluoranthene compound represented by the following formula (5) is preferable.

(In the formula, X _{101 to} X ₁₀₆ and X _{108 to} X ₁₁₁ each independently represent a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted ring atom number of 5; -30 heterocyclic group, substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 8 ring carbon atoms, substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms Group, substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 50 ring atoms, substituted or unsubstituted arylthio group having 5 to 50 ring atoms, substituted Or an unsubstituted alkoxycarbonyl group having 2 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a halogen atom, cyano , Nitro group, selected from hydroxyl and carboxyl groups.
X ₁₀₇ and X ₁₁₂ are each independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, a substituted or unsubstituted carbon, It is selected from an alkyl group having 1 to 20 and a substituted or unsubstituted cycloalkyl group having 3 to 8 ring carbon atoms.
However, _X103 and _X104 are mutually different substituents.
Further, in X _{101 to} X ₁₁₂ , adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure, and these cyclic structures may be substituted. )

X ₁₀₃ or X _{104 in} formula (5) is preferably a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms. Further, a preferred substituent of “substituted or unsubstituted” in formula (5) is a cyano group or a halogen atom.
In the formula (5), those exemplified above as examples of the aryl group, heterocyclic group, alkyl group, cycloalkyl group, alkoxy group, aralkyl group, aryloxy group, arylthio group, alkoxycarbonyl group and halogen atom. It is done.

  A suitable host for phosphorescence emission is a compound having a function of causing the phosphorescence emission compound to emit light as a result of energy transfer from the excited state to the phosphorescence emission compound. The host compound is not particularly limited as long as it has a large triplet energy gap and can transfer exciton energy to the phosphorescent compound, and can be appropriately selected according to the purpose.

Specific examples of such host compounds include condensed ring compounds composed of combinations of benzene rings, naphthalene rings, and heterocyclic rings, carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives. , Pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene Compounds, porphyrin compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives Metal complexes of fluorenylidenemethane derivatives, distyrylpyrazine derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanine derivatives, 8-quinolinol derivatives, metal phthalocyanines, benzoxazoles and benzothiazoles Various metal complexes represented by polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorenes And high molecular compounds such as derivatives. A host compound may be used independently and may use 2 or more types together.
Specific examples include the following compounds.

  A phosphorescent dopant is a compound that can emit light from triplet excitons. Although it is not particularly limited as long as it emits light from triplet excitons, it is preferably a metal complex containing at least one metal selected from the group consisting of Ir, Ru, Pd, Pt, Os and Re, and is preferably a porphyrin metal complex or ortho Metalated metal complexes are preferred. The porphyrin metal complex is preferably a porphyrin platinum complex. The phosphorescent compounds may be used alone or in combination of two or more.

  There are various ligands that form orthometalated metal complexes. Preferred ligands include 2-phenylpyridine derivatives, 7,8-benzoquinoline derivatives, and 2- (2-thienyl) pyridine derivatives. , 2- (1-naphthyl) pyridine derivatives, 2-phenylquinoline derivatives, and the like. These derivatives may have a substituent if necessary. In particular, a fluorinated compound or a compound having a trifluoromethyl group introduced is preferable as a blue dopant. Furthermore, you may have ligands other than the said ligands, such as an acetylacetonate and picric acid, as an auxiliary ligand.

  There is no restriction | limiting in particular as content in the light emitting layer of a phosphorescence-emitting dopant, Although it can select suitably according to the objective, For example, it is 0.1-70 mass%, and 1-30 mass% is preferable. When the content of the phosphorescent compound is 0.1% by mass or more, it is possible to prevent the emission of light from being weakened and to sufficiently exhibit the content effect. By setting the content to 70% by mass or less, a phenomenon called concentration quenching can be suppressed and deterioration of device performance can be prevented.

The light emitting layer may contain a hole transport material, an electron transport material, and a polymer binder as necessary.
The thickness of the light emitting layer is preferably 5 to 50 nm, more preferably 7 to 50 nm, and most preferably 10 to 50 nm. When the thickness is 5 nm or more, the light emitting layer can be easily formed, and the chromaticity can be easily adjusted. By setting the thickness to 50 nm or less, it is possible to prevent the drive voltage from increasing.

(B) Hole transport zone Layers in the hole transport zone include a hole transport layer and a hole injection layer. The hole transport layer is a layer that assists hole injection into the light emitting layer and transports it to the light emitting region, and has a high hole mobility and a small ionization energy of usually 5.5 eV or less. Such a hole transport layer is preferably a material that transports holes to the light-emitting layer with a lower electric field strength, and further has a hole mobility of at least 10 when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied. ^-4 cm ² / V · sec is preferable.

  Specific examples of the material for the hole transport layer include, for example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives. , Styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, polysilanes, aniline copolymers, conductive polymer oligomers (particularly thiophene oligomers), and the like.

For the hole injection layer or the hole transport layer (including the hole injection transport layer), an aromatic amine compound, for example, an aromatic amine derivative represented by the following formula (6) is preferably used.

In the formula (6), Ar ^{31 to} Ar ³⁴ are aromatic hydrocarbon groups having 6 to 50 ring carbon atoms (however, they may have a substituent), condensed aromatics having 6 to 50 ring carbon atoms. Group hydrocarbon group (which may have a substituent), aromatic heterocyclic group having 2 to 40 ring carbon atoms (which may have a substituent) 40 condensed aromatic heterocyclic groups (which may have a substituent), a group obtained by bonding these aromatic hydrocarbon groups and these aromatic heterocyclic groups, these aromatic hydrocarbon groups and these A group in which a condensed aromatic heterocyclic group is bonded, a group in which the condensed aromatic hydrocarbon group and the aromatic heterocyclic group are bonded, or a condensed aromatic hydrocarbon group and the condensed aromatic heterocyclic group Represents a group to which is bonded.
L represents a single bond or a group similar to Ar ^{31 to} Ar ³⁴ .

Moreover, the aromatic amine of following formula (7) is also used suitably for formation of a positive hole injection layer or a positive hole transport layer.

In the formula (7), the definition of Ar ^{31 to} Ar ^{33 is the same as} the definition of Ar ^{31 to} Ar ^{34 in} the formula (6).

  The hole injection layer is a layer provided to further assist hole injection. As the material of the hole injection layer, the same material as that of the hole transport layer can be used. In addition, a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound can also be used. Furthermore, HAT or F4TCNQ used in the P layer of the charge generation layer, or a compound represented by the formula (6) can also be used.

Further, conductive oligomers such as thiophene-containing oligomers and arylamine oligomers disclosed in JP-A-8-193191, conductive dendrimers such as arylamine dendrimers, and the like can also be used.
In addition to aromatic dimethylidin compounds, inorganic compounds such as p-type Si and p-type SiC can also be used as the material for the hole injection layer.

  The hole injection layer or the hole transport layer can be formed, for example, by thinning the above-described compound by a known method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. Although the film thickness as a positive hole injection layer and a positive hole transport layer does not have a restriction | limiting in particular, Usually, they are 1 nm-5 micrometers.

(C) Electron transport zone Layers of the electron transport zone include an electron injection layer and an electron transport layer (hereinafter referred to as an electron injection layer / transport layer).
The electron injection layer / transport layer assists the injection of electrons into the light emitting layer and transports it to the light emitting region, and has a high electron mobility.
The electron injection layer and the transport layer are appropriately selected with a film thickness of several nm to several μm. In particular, when the film thickness is large, in order to avoid an increase in voltage, the electron mobility is applied when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied. Is preferably at least 10 ⁻⁵ cm ² / Vs or more.
As a material used for the electron injection layer / transport layer, 8-hydroxyquinoline or a metal complex of its derivative or a nitrogen-containing heterocyclic derivative is preferable.
As a specific example of the metal complex of 8-hydroxyquinoline or its derivative, a metal chelate oxinoid compound containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline), for example, tris (8-quinolinol) aluminum, is injected. It can be used as a material.
As the nitrogen-containing heterocyclic derivative, for example, oxazole, thiazole, oxadiazole, thiadiazole, triazole, pyridine, pyrimidine, triazine, phenanthroline, benzimidazole, imidazopyridine and the like are preferable, and among them, benzimidazole derivative, phenanthroline derivative, imidazopyridine derivative Is preferred.

(Charge generation layer)
When a voltage is applied, the charge generation layer injects holes into the light emitting unit disposed on the cathode side of the charge generation layer, while injecting electrons into the light emission unit disposed on the anode side of the charge generation layer. It is a layer that plays a role.
The charge generation layer according to one embodiment of the present invention includes an N layer formed on the anode side and a P layer formed on the cathode side. The charge generation layer may have an N layer and a P layer, and may be a stacked body including the N layer and the P layer, or another layer may be interposed between the N layer and the P layer.

The N layer preferably includes a π electron deficient compound and an electron donating material.
Examples of the π electron deficient compound include compounds capable of coordinating with metal atoms. Specific examples include phenanthroline compounds, benzimidazole compounds, quinolinol, and the like.

As the phenanthroline-based compound, compounds represented by the following formulas (I ′) to (III ′) are preferable. Among these, compounds represented by the following formula (I ′) or (II ′) are preferable.

In the above formulas (I ′) to (III ′), R ^{1a to} R ^7a , R ^{1b to} R ^7b , and R ^{1c to} R ^6c each independently represent a hydrogen atom, a substituted or unsubstituted ring carbon number of 6 ~ 60 aryl group, substituted or unsubstituted pyridyl group, substituted or unsubstituted quinolyl group, substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms Substituted or unsubstituted aralkyl groups having 7 to 50 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 50 carbon atoms, substituted or unsubstituted aryloxy groups having 6 to 50 ring carbon atoms, substituted or unsubstituted And an arylthio group having 6 to 50 ring carbon atoms, a substituted or unsubstituted alkoxycarbonyl group having 2 to 50 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. Amino group, a halogen atom, a cyano group, a nitro group, a hydroxyl group or a carboxyl group.
Of R ^{1a to} R ^7a , R ^{1b to} R ^7b , or R ^{1c to} R ^6c , adjacent ones may be bonded to each other to form a ring. Examples of the ring include a benzene ring, a naphthalene ring, a pyrazine ring, a pyridine ring, and a furan ring.
L ^1a and L ^1b are each a single bond or a linking group. Examples of the linking group include a substituted or unsubstituted aromatic group having 6 to 20 ring carbon atoms, a substituted or unsubstituted alkylene chain having 1 to 8 carbon atoms, and a substituted or unsubstituted heterocyclic ring. Specifically, a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted methylene chain, or a substituted or unsubstituted pyridine ring is preferable.
Ar ^1a , Ar ^1b , Ar ^1c and Ar ^2c are each a substituted or unsubstituted aromatic group having 6 to 60 carbon atoms.
n is 1-4, and when n is 2 or more, the groups having a phenanthroline skeleton in parentheses may be the same or different.

The compound represented by the formula (I ′) or (II ′) is represented by the following formula (I′-a), (I′-b), (II′-a) or (II′-b). Are preferred.

  By having a group having a phenanthroline skeleton and a group having an anthracene skeleton, it is possible to achieve both a function as an electron acceptor and a transport ability as an electron transport layer. Furthermore, deposition stability and film formability are improved.

In the formulas (I′-a), (I′-b), (II′-a) and (II′-b), R ^{1a to} R ^7a , R ^{1b to} R ^7b , L ^1a and L ^1b are respectively The same group as R ^{< 1a} > -R <^7a> , R ^<1b > -R <^7b> , L ^<1a> and L ^{< 1b} > in Formula (I ') and (II') is represented.
R ^{11a to} R ^20a and R ^{11b to} R ^20b are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted quinolyl. Group, substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, substituted or unsubstituted aralkyl group having 7 to 50 ring carbon atoms, substituted or unsubstituted Substituted alkoxy group having 1 to 50 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, substituted or unsubstituted arylthio group having 5 to 50 ring carbon atoms, substituted or unsubstituted carbon An alkoxycarbonyl group having 2 to 50 amino acids, an amino group substituted with a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, a halogen atom, Anomoto, a nitro group, a hydroxyl group or a carboxyl group.
Of R ^{11a to} R ^20a or R ^{11b to} R ^20b , adjacent ones may be bonded to each other to form a ring. Examples of the ring include a benzene ring, a naphthalene ring, a pyrazine ring, a pyridine ring, and a furan ring.

The aryl group having 6 to 60 ring carbon atoms preferably has 6 to 30 carbon atoms, particularly preferably 6 to 20 carbon atoms. For example, phenyl, fluorenyl, naphthyl, anthryl, phenanthryl, chrysenyl, pyrenyl, triphenylenyl, fluorane. And tenenyl.
Examples of the aromatic group represented by Ar ^1a , Ar ^1b , Ar ^1c and Ar ^2c include the above-described aryl group and a divalent or higher-valent group derived by removing a hydrogen atom from the aryl group.
R ^{1a to} R ^7a and R ^{1b to} R ^{7b in the} formulas (I ′) and (II ′) are preferably hydrogen, phenyl, or naphthyl.

  Examples of the alkyl group having 1 to 50 carbon atoms include a linear or branched alkyl group. Preferably it is C1-C20, More preferably, it is C1-C12, Most preferably, it is C1-C8, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl etc. are mentioned.

  Examples of the cycloalkyl group having 3 to 50 ring carbon atoms include cyclopentyl and cyclohexyl.

  The aralkyl group having 7 to 50 carbon atoms is represented by -Y-Z, and examples of Y include alkylene examples corresponding to the above examples of alkyl groups, and examples of Z include examples of the above aryl groups. It is done. The aryl part of the aralkyl group preferably has 6 to 30 carbon atoms. The alkyl moiety preferably has 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms. For example, a benzyl group, a phenylethyl group, and a 2-phenylpropan-2-yl group.

  A C1-C50 alkoxy group is represented as -OY and the example of said alkyl group is mentioned as an example of Y. The alkoxy group preferably has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, and examples thereof include methoxy, ethoxy, propoxy, butoxy and the like.

  The aryloxy group having 6 to 50 ring carbon atoms is represented as -OY, and examples of Y include the above aryl groups. Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12, for example, phenyloxy, 2-naphthyloxy, etc. are mentioned.

  The arylthio group having 6 to 50 ring carbon atoms is represented by -SY, and examples of Y include the above aryl groups. Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12, for example, phenylthio etc. are mentioned.

  The alkoxycarbonyl group having 2 to 50 carbon atoms preferably has 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms, and examples thereof include methoxycarbonyl and ethoxycarbonyl.

  Examples of the amino group substituted with a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms include diarylamino, alkylarylamino, and arylamino. Examples of the alkyl group and aryl group bonded to the nitrogen atom include the above-described aryl group and alkyl group. Preferably it has 6 to 20 carbon atoms, more preferably 6 to 12 carbon atoms, particularly preferably 6 carbon atoms, and examples thereof include diphenylamino and the like.

  As a halogen atom, a fluorine atom, a chlorine atom, and a bromine atom are mentioned, Preferably it is a fluorine atom.

As the substituent for each of the above groups, each independently a linear or branched alkyl group having 1 to 20 carbon atoms, a linear or branched alkenyl group having 2 to 20 carbon atoms, or a ring-forming carbon number of 3 A cycloalkyl group having 20 to 20 carbon atoms, a trialkylsilyl group having an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 24 ring carbon atoms or a silyl group having an alkyl group, an alkyl group having 1 to 20 carbon atoms and a ring An alkylarylsilyl group having an aryl group having 6 to 24 carbon atoms, an aryl group having 6 to 24 ring carbon atoms, a heteroaryl group having 5 to 24 ring atoms, an alkoxy group having 1 to 20 carbon atoms, a halogen atom Or it is a cyano group. Specific examples include the aryl group, alkyl group, cycloalkyl group, heteroaryl group, alkoxy group, halogen atom, and cyano group. Furthermore, these groups may have a similar substituent.
Examples of the alkenyl group include a substituent having an unsaturated bond in the molecule of the alkyl group described above.
Examples of the silyl group having an aryl group include a triarylsilyl group, an alkylarylsilyl group, and a trialkylsilyl group.
Examples of suitable substituents include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, trimethylsilyl, triphenylsilyl.
Specific examples of the compounds represented by formulas (I ′) to (III ′) are shown below.

  For the synthesis of the compounds represented by the formulas (I ′) and (II ′), reference can be made to WO2007 / 018004, WO2006 / 64484, WO2006 / 021982.

Examples of the benzimidazole compound include benzimidazole derivatives represented by the following formula (III ′).

In the formula, A ₁₄ has a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a polycyclic aromatic hydrocarbon group condensed with 3 to 40 aromatic rings, It is a 6-60 substituted or unsubstituted hydrocarbon group, or a nitrogen-containing heterocyclic group.
Specific examples of the halogen atom and the alkyl group having 1 to 20 carbon atoms are the same as those in the above formula (I ′).

A polycyclic aromatic hydrocarbon group having 3 to 40 aromatic rings condensed, and a polycyclic aromatic hydrocarbon group having 6 to 60 carbon atoms in which 3 to 40 aromatic rings are condensed. Examples of the aromatic hydrocarbon group include anthracene, naphthacene, pentacene, pyrene and chrysene. Examples of the hydrocarbon group having 6 to 60 carbon atoms include an alkyl group, a cycloalkyl group, and an aryl group. In addition, these specific examples are the same as that of Formula (I ') mentioned above. As the hydrocarbon group, an aryl group is preferable, and among them, a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, a fluorenyl group, and the like are preferable. These may have a substituent.
Examples of the nitrogen-containing heterocyclic group include a pyridine ring and triazine.

B is a single bond or a substituted or unsubstituted aromatic ring group. As the aromatic ring group, a phenylene group and an anthracenylene group are preferable.
R ₃₁ and R ₃₂ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 60 carbon atoms, substituted or unsubstituted, It is an unsubstituted nitrogen-containing heterocyclic group or a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms. Specific examples of the groups are the above-mentioned formula (I '), an similar to A _14.
Specific examples of the compound represented by the formula (III ′) are shown below.

  As quinolinol, 8-hydroxyquinoline is preferable.

  Examples of the electron donating material include an electron donating metal element, a metal compound, and a metal complex. Specifically, alkali metals, alkali metal compounds, organometallic complexes containing alkali metals, alkaline earth metals, alkaline earth metal compounds, organometallic complexes containing alkaline earth metals, rare earth metals, rare earth metal compounds, and rare earth metals Of the organometallic complexes containing, a layer containing at least one is preferable. Among these, it is preferable to contain at least one of an alkali metal, an alkaline earth metal, a rare earth metal, a rare earth metal compound, and a rare earth metal complex.

Examples of the alkali metal include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs) and the like, and those having a work function of 2.9 eV or less are particularly preferable. Of these, Li, K, Rb, and Cs are preferable, Li, Rb, and Cs are more preferable, and Li is most preferable.
Examples of the alkaline earth metal include calcium (Ca), magnesium (Mg) strontium (Sr), barium (Ba) and the like, and those having a work function of 2.9 eV or less are particularly preferable.
Examples of the rare earth metal include scandium (Sc), yttrium (Y), cerium (Ce), terbium (Tb), ytterbium (Yb) and the like, and those having a work function of 2.9 eV or less are particularly preferable.
Among the above metals, preferred metals are particularly high in reducing ability, and by adding a relatively small amount to the electron injection region, it is possible to improve the light emission luminance and extend the life of the organic EL element.

Examples of the alkali metal compound include lithium oxide (Li ₂ O), cesium oxide (Cs ₂ O), alkali oxides such as potassium oxide (K ₂ O), lithium fluoride (LiF), sodium fluoride (NaF), fluorine. Examples thereof include alkali halides such as cesium fluoride (CsF) and potassium fluoride (KF), and lithium fluoride (LiF), lithium oxide (Li ₂ O), and sodium fluoride (NaF) are preferable.
Examples of the alkaline earth metal compound include barium oxide (BaO), strontium oxide (SrO), calcium oxide (CaO), and barium strontium oxide (Ba _x Sr _1-x O) (0 <x <1), Examples thereof include barium calcium acid (Ba _x Ca _1-x O) (0 <x <1), and BaO, SrO, and CaO are preferable.
The rare earth metal compound, ytterbium fluoride _(YbF 3), scandium fluoride _(ScF 3), scandium oxide _(ScO 3), yttrium oxide _{(Y 2 O} 3), cerium oxide _{(Ce 2 O} 3), gadolinium fluoride _(GdF 3), include such terbium fluoride (TbF _{3) is, YbF 3, ScF 3, TbF} 3 are preferable.

  As described above, the organometallic complex is not particularly limited as long as it contains at least one of alkali metal ions, alkaline earth metal ions, and rare earth metal ions as metal ions. The ligands include quinolinol, benzoquinolinol, acridinol, phenanthridinol, hydroxyphenyl oxazole, hydroxyphenyl thiazole, hydroxydiaryl thiadiazole, hydroxydiaryl thiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxybenzotriazole, Hydroxyfulborane, bipyridyl, phenanthroline, phthalocyanine, porphyrin, cyclopentadiene, β-diketones, azomethines, and derivatives thereof are preferred, but are not limited thereto.

  The addition form of the metal, compound and complex is preferably formed in a layered or island shape in the interface region. As a forming method, while vapor-depositing at least one of the above metal, compound and complex by resistance heating vapor deposition, an organic material which is a light emitting material or an electron injection material for forming an interface region is simultaneously deposited, and the above metal, A method of dispersing at least one of the compound and the complex is preferable. The dispersion concentration is usually organic matter (π electron deficient compound): metal, compound and complex = 1000: 1 to 1: 1000, preferably 100: 1 to 1: 1 in terms of film thickness ratio.

  When forming at least one of the metal, the compound and the complex in a layered form, after forming the light emitting material or the electron injecting material which is an organic layer at the interface in a layered form, at least one of the metal, the compound and the complex is singly used. Vapor deposition is performed by resistance heating vapor deposition, and the layer is preferably formed with a thickness of 0.1 nm to 15 nm.

  When forming at least one of the metal, compound, and complex in an island shape, after forming a light emitting material or an electron injection material, which is an organic layer at the interface, in an island shape, at least one of the metal, the compound, and the complex is formed. Vapor deposition is performed by a resistance heating vapor deposition method alone, and is preferably formed with an island thickness of 0.05 nm to 1 nm.

Moreover, as a ratio of the main component and at least one of the above metal, compound, and complex in the N layer, the main component: electron-donating dopant and / or organometallic complex = 100: 1 to 1: 1 is preferable, and 50: 1 to 4: 1 is more preferable.
The film thickness of the N layer is preferably 0.1 nm to 100 nm, and particularly preferably 1 nm to 50 nm.

（式中、Ｒ^１ｃ〜Ｒ^６ｃは、それぞれ独立に、水素原子、置換若しくは無置換の環形成炭素数６〜６０のアリール基、置換若しくは無置換のピリジル基、置換若しくは無置換のキノリル基、置換若しくは無置換の炭素数１〜５０のアルキル基、置換若しくは無置換の炭素数３〜５０のシクロアルキル基、置換若しくは無置換の環形成炭素数７〜５０のアラルキル基、置換若しくは無置換の炭素数１〜５０のアルコキシ基、置換若しくは無置換の環形成炭素数６〜５０のアリールオキシ基、置換若しくは無置換の環形成炭素数６〜５０のアリールチオ基、置換若しくは無置換の炭素数２〜５０のアルコキシカルボニル基、置換若しくは無置換の環形成炭素数６〜５０のアリール基で置換されたアミノ基、ハロゲン原子、シアノ基、ニトロ基、ヒドロキシル基又はカルボキシル基である。）The P layer preferably contains a compound represented by the following formula (III).
The compound represented by the formula (III) can improve characteristics such as efficiency, voltage, and lifetime of the device.

(Wherein, R ^{1c to} R ^6c each independently represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted quinolyl group, Substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, substituted or unsubstituted aralkyl group having 7 to 50 ring carbon atoms, substituted or unsubstituted An alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, a substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, a substituted or unsubstituted carbon number 2 ˜50 alkoxycarbonyl group, substituted or unsubstituted amino group substituted with an aryl group having 6 to 50 ring carbon atoms, halogen atom, cyano group, nitro group, Dorokishiru a group or a carboxyl group.)

Specific examples of the substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms and the like are the same as the above examples.
Specific examples of the compound of formula (III) are shown below. For other examples, reference can be made to Special Tables 2011-521414.

The P layer may preferably contain a compound represented by the following formula (IV) in addition to the compound represented by the above formula (III). The compound represented by the formula (IV) can improve characteristics such as efficiency, voltage, and life of the device.

In the formula (IV), Ar ¹ is an aromatic ring having 6 to 24 ring carbon atoms or a heterocyclic ring having 5 to 24 ring atoms, preferably an aromatic ring having 6 to 14 ring carbon atoms or the number of ring forming atoms. It is a 5-14 heterocyclic ring. Examples of the aromatic ring include a benzene ring, a naphthalene ring, a fluorene ring, a 9,9-dimethylfluorene ring, and a 9,9-dioctylfluorene ring. Examples of the heterocyclic ring include a pyrazine ring, a pyridine ring, a quinoxaline ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furan ring, a benzofuran ring, a dibenzofuran ring, a phenanthroline ring, a naphthyridine ring, and a tetraazaanthracene ring. The aromatic ring and heterocyclic ring are substituted or unsubstituted alkyl groups, substituted or unsubstituted cycloalkyl groups, substituted or unsubstituted alkenyl groups, substituted or unsubstituted aryl represented by R ^{1 to} R ⁴ described below. Group, substituted or unsubstituted heterocyclic group, halogen atom, substituted or unsubstituted fluoroalkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted fluoroalkoxy group, substituted or unsubstituted aryloxy group, substituted or It may be substituted with an unsubstituted aralkyloxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, or a cyano group.

In formula (IV), R ^{1 to} R ⁴ may be the same or different from each other, and are a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group. Substituted or unsubstituted aryl group, substituted or unsubstituted heterocyclic group, halogen atom, substituted or unsubstituted fluoroalkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted fluoroalkoxy group, substituted or unsubstituted A substituted aryloxy group, a substituted or unsubstituted aralkyloxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, or a cyano group. R ¹ and R ² and R ³ and R ⁴ may be bonded to each other to form a ring.

Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and an octyl group.
Examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group.
Alkenyl groups include vinyl groups, propenyl groups (including double bond positional isomers), butenyl groups (including double bond positional isomers), pentenyl groups (including double bond positional isomers), etc. can give.
As the (substituted) aryl group, phenyl group, biphenyl group, naphthyl group, fluorophenyl group, trifluoromethylphenyl group, (trifluoromethyl) fluorophenyl group, trifluorophenyl group, bis (trifluoromethyl) phenyl group, (Trifluoromethyl) difluorophenyl group, trifluoromethoxyphenyl group, trifluoromethoxyfluorophenyl group and the like can be mentioned.
Examples of the heterocyclic group include residues such as pyridine, pyrazine, furan, imidazole, benzimidazole, and thiophene.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the fluoroalkyl group include a trifluoromethyl group, a pentafluoroethyl group, a perfluorocyclohexyl group, and a perfluoroadamantyl group.
Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the fluoroalkoxy group include trifluoromethoxy group, pentafluoroethoxy group, 2,2,2-trifluoroethoxy group, 2,2,3,3,3-pentafluoropropoxy group, 2,2,3,3- Examples thereof include a tetrafluoropropoxy group and a 1,1,1,3,3,3-hexafluoropropan-2-yloxy group.
Examples of the (substituted) aryloxy group include a phenyloxy group, a pentafluorophenyloxy group, and a 4-trifluorophenyloxy group.
Examples of (substituted) aralkyloxy groups include benzyloxy group, pentafluorobenzyloxy group, 4-trifluoromethylbenzyloxy group and the like.
Examples of (substituted) amino groups include amino groups, mono- or dimethylamino groups, mono- or diethylamino groups, mono- or diphenylamino groups, and the like.
Examples of (substituted) silyl groups include silyl groups, mono-, di- or trimethylsilyl groups, mono-, di- or triethylsilyl groups, mono-, di- or triphenylsilyl groups.

Examples of the optional substituent for R ^{1 to} R ⁴ include the halogen atom, cyano group, alkyl group, aryl group, fluoroalkyl group, fluoroalkoxy group, and heterocyclic group mentioned above.
In the following, unless otherwise specified, examples of the optional substituents referred to as “substituted or unsubstituted” include the halogen atoms, cyano groups, alkyl groups, aryl groups, fluoroalkyl groups, fluoroalkoxy groups, and heterocycles mentioned above. A cyclic group is mentioned.

As described above, R ¹ and R ² and R ³ and R ⁴ may be bonded to each other to form a ring. Examples of the ring include a benzene ring, a naphthalene ring, a pyrazine ring, a pyridine ring, and a furan ring.
Furthermore, at least one of R ^{1 to} R ⁴ is a fluorine atom, a fluoroalkyl group, a fluoroalkoxy group, a cyano group, or at least one group selected from fluorine, a fluoroalkyl group, a fluoroalkoxy group, and a cyano group. An aryl group or a heterocyclic group is preferable. By using these as substituents, electron acceptability can be increased, an appropriate sublimation temperature can be obtained, or crystallization can be suppressed.

Rg ¹ and Rg ² in the formula (IV) may be the same as or different from each other, and are represented by the following formula (i) or (ii).

In the above formula, X ¹ and X ² may be the same as or different from each other, and are any of the divalent groups shown in the following (a) to (g). Particularly, (a) to (c) are preferable from the viewpoints of excellent heat resistance or ease of synthesis.

In the above formula, R ^{21 to} R ²⁴ may be the same or different from each other, and are a hydrogen atom, a substituted or unsubstituted fluoroalkyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, A substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, R ²² and R ²³ may be bonded to each other to form a ring. Specific examples of the fluoroalkyl group, the alkyl group, the cycloalkyl group, the aryl group, and the heterocyclic group include the groups exemplified for R ^{1 to} R ⁴ .

In formula (IV), Y ^{1 to} Y ⁴ may be the same as or different from each other, and each represents N, CH, or C (R ⁵ ), and R ⁵ represents the same group as R ^{1 to} R ^4. .
In addition, it is preferable that at least one of Y ^{1 to} Y ⁴ is a nitrogen atom (the same applies to Y ²¹ to Y ²⁶ and Y ^{31 to} Y ³⁸ described later). Since at least one is a nitrogen atom, electron acceptability can be increased, heat resistance can be increased, or crystallization can be suppressed.

The indenofluorangeone derivative of formula (IV) is preferably represented by the following formula (IV-A) or (IV-B). Each symbol such as Ar ^{1 in} the following formula (IV-A) has the same meaning as in formula (IV). Ar ² in the following formula (IV-B) has the same meaning as Ar ¹ in formula (IV), X ³ and X ⁴ have the same meaning as X ¹ and X ² in formula (IV), and Y ^{5 to} Y ⁸ has the same meaning as ^Y 1 to Y ⁴ in formula ^(IV), R 1 ~R ⁴ has the same meaning as ^R 1 to R ⁴ in formula (IV).

More preferably, the indenofluorangeone derivative of the formula (IV) is represented by the following formulas (IVa) to (IVi).

In the above formulas, ^{X 1} and ^{X 2,} R 1 ^{~R 4} has the same meaning as ^{X 1} and ^{X 2,} R 1 ^{~R 4} in formula ^{(IV), Y 21 ~Y 26} , Y 31 ~Y 38 and, Y ^{41 to} Y ⁵⁰ have the same meanings as Y ^{1 to} Y ⁴ in formula (IV).

Particularly preferred indenofluorangeone derivatives of the formula (IV) are represented by the following formulas (IV-a) to (IV-r). The following formulas (IV-b), (IV-d), (IV-f), (IV-h), (IV-j), (IV-l), (IV-n), (IV-p) ), And (IV-r), there are a plurality of isomers depending on the configuration of the cyano group of two cyanoimino groups, but only a specific isomer or a mixture of two or more isomers may be present. It may be.

In the above ^formulas, R 31 ^{to R 52} have the same meanings as ^R 1 to R ⁴ in formula (IV). R ^{31 to} R ⁵² adjacent to each other may be bonded to each other to form a ring. In particular, at least one of R ^{31 to} R ⁵² is a fluorine atom, a fluoroalkyl group, a fluoroalkoxy group, a cyano group, or an aryl having at least one group selected from fluorine, a fluoroalkyl group, a fluoroalkoxy group, and a cyano group It is preferably a group or a heterocyclic group.

  Since the indenofluorangeone derivative has the structure of each of the above formulas, it has electron acceptability, is excellent in heat resistance, has a sublimation temperature of about 200 ° C. or higher, and can be purified by sublimation. High purity can be achieved. Moreover, the drive voltage of an element can be reduced by using it for an organic EL element, and lifetime can be improved. Furthermore, since the sublimation temperature is about 200 ° C. or higher during the manufacture of the element, it does not scatter inside the deposition film forming apparatus, so that the film forming apparatus or the organic EL element is not contaminated.

Specific examples of the indenofluorangeone derivative of the formula (IV) are shown below, but are not limited thereto.

The P layer may be a layer made of only the compound represented by the formula (III) or (IV), or may be a layer made of a mixture with other materials. In one embodiment of the present invention, it is preferable that the P layer is a layer made of only the compound represented by the formula (III) or (IV) or a layer containing at least one kind of hole transport material.
As the hole transport material, materials used in the above-described hole transport zone can be used. Of these, aromatic tertiary amine compounds are preferred.
The content of the compound represented by formula (III) or (IV) in the P layer is preferably 0.1% by weight to 100% by weight, particularly 10% by weight to 100% by weight. preferable.

  The thickness of the P layer is preferably 1 nm to 50 nm, and particularly preferably 5 nm to 20 nm.

(substrate)
The organic EL element according to one embodiment of the present invention is manufactured over a substrate. The substrate supports the organic EL element. In the case where light from the light emitting unit is extracted through the substrate, the substrate needs to be translucent. In this case, the light transmittance in the visible region of 400 to 700 nm is preferably 50% or more.
Specifically, a glass plate, a polymer plate, etc. are mentioned. Examples of the glass plate include soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.
In addition, translucency is unnecessary when a support substrate is located on the opposite side to the light extraction direction.

(anode)
The anode of the organic EL element plays a role of injecting holes into the hole transport layer or the light emitting layer. When transparency is required on the anode side, indium tin oxide alloy (ITO), tin oxide (NESA), indium zinc oxide alloy (IZO), gold, silver, platinum, copper, or the like can be applied. In addition, when a reflective electrode that does not require transparency is used, in addition to these metals, metals such as silver, aluminum, molybdenum, chromium, nickel, and alloys with other metals can be used. .
These materials can be used alone, but an alloy of these materials or a material to which other elements are added can be appropriately selected and used.

  The anode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. When light emitted from the light emitting layer is extracted from the anode, the transmittance of the anode for light emission is preferably greater than 10%. The sheet resistance of the anode is preferably several hundred Ω / □ or less. Although the film thickness of the anode depends on the material, it is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

(cathode)
As the cathode, a metal, an alloy, an electrically conductive compound having a low work function (4 eV or less), and a mixture thereof and an electrode material thereof are used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / silver alloy, aluminum, aluminum / aluminum oxide, aluminum / lithium alloy, indium, and rare earth metals.
The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.

  Here, when light emitted from the light emitting layer is taken out from the cathode, it is preferable that the transmittance with respect to the light emitted from the cathode is larger than 10%. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually 10 nm to 1 μm, preferably 50 to 200 nm.

(Other components)
In one embodiment of the present invention, an electron injection layer formed of an insulator or a semiconductor may be provided between the cathode and the organic layer. As a result, current leakage can be effectively prevented and the electron injection property can be improved.

  As such an insulator, it is preferable to use at least one metal compound selected from the group consisting of alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides and alkaline earth metal halides. If the electron injection layer is composed of these alkali metal chalcogenides or the like, it is preferable in that the electron injection property can be further improved.

Specifically, preferable alkali metal chalcogenides include, for example, Li ₂ O, LiO, Na ₂ S, Na ₂ Se, and NaO, and preferable alkaline earth metal chalcogenides include, for example, CaO, BaO, SrO, and BeO. , BaS, and CaSe. Further, preferable alkali metal halides include, for example, LiF, NaF, KF, CsF, LiCl, KCl, and NaCl. Examples of preferable alkaline earth metal halides include fluorides such as CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ and BeF ₂ , and halides other than fluorides.

The semiconductor constituting the electron injection layer includes Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na, Cd, Mg, Si, Ta, Sb, and an oxide or nitride containing at least one element of Zn. One kind or a combination of two or more kinds of substances or oxynitrides.
In addition, the inorganic compound constituting the electron injection layer is preferably a microcrystalline or amorphous insulating thin film.
Examples of such inorganic compounds include the alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides, and alkaline earth metal halides described above.

  Although one form of the organic EL element of the present invention has been described by exemplifying the organic EL element 1 of FIG. 1, the present invention is not limited to the form of the organic EL element 1. For example, in the organic EL element 1, two light emitting units are formed, but three or more light emitting units may be formed.

FIG. 2 is a schematic cross-sectional view of a second embodiment of an organic EL element according to one embodiment of the present invention.
The organic EL element 2 includes the anode 20, the first light emitting unit 30A, the charge generating layer 40A, the second light emitting unit 30B, the charge generating layer 40B, the third light emitting unit 30C, and the cathode 50 on the substrate 10. Prepare in order. The organic EL element 2 has the same configuration as the organic EL element 1 shown in FIG. 1 except that three light emitting units are formed.
In the present embodiment, for example, by changing the emission color of each light emitting unit to red, green, and blue, it is possible to obtain a white light emitting EL element with high color rendering properties that harmoniously includes light in three wavelength regions.

The organic EL element according to one embodiment of the present invention exhibits an excellent effect particularly when a plurality of elements are formed on a substrate like a pixel of a display device, for example.
FIG. 3 is a schematic view showing an example in which three organic EL elements A-C (100A to 100C) are formed on a substrate.
On the substrate 10, there are anodes 20A, 20B, 20C patterned in stripes. The first light emitting unit 30A, the charge generation layer 40, and the second light emitting unit 30B are formed in this order in common on the substrate 10 and each anode. On the second light emitting unit 30 </ b> B, the cathode 50 is formed in a stripe shape so as to be orthogonal to the anode 20.
The organic EL elements A to C emit light when a voltage is applied between the anodes 20A to 20C and the cathode 50 facing each other. For example, when a voltage is applied between the anode 20B and the cathode 50, the element B emits light.

The organic EL element according to one embodiment of the present invention is particularly suitable as a light emitting element of a color display device using a color filter.
FIG. 4 is a schematic cross-sectional view of a color display device using an organic EL element according to an embodiment of the present invention.
In the color display device 3, a color filter 60 including a red color filter (RCF) 61, a green color filter (GCF) 62, and a blue color filter (BCF) 63 is formed on the light extraction side of the organic EL element shown in FIG. Is. In the present embodiment, the light emitting color of the first light emitting unit 30A is blue and the light emitting color of the second light emitting unit 30B is yellow, whereby an organic EL element that emits white light is obtained. Only a desired color is extracted from the white light to the outside of the display device by the color filter.

  The organic EL device according to one embodiment of the present invention can be manufactured by a known method. Specifically, the anode and the cathode can be formed by a method such as vapor deposition or sputtering. Each organic layer such as a light emitting unit can be formed by a method such as vacuum deposition, spin coating, casting, or LB.

Hereinafter, an organic EL element was manufactured and evaluated. The materials used for production are as follows.

Example 1
ITO was formed to a thickness of 240 nm as an anode on a substrate made of a 30 mm × 30 mm glass plate. Next, a cell for an organic EL element in which a region other than the light emitting region of 2 mm × 2 mm was masked with an insulating film (not shown) by SiO ₂ vapor deposition was produced.
On the anode, hexanitrile azatriphenylene (HAT) having the above structure was formed as a hole injection layer with a thickness of 10 nm.
A blue light-emitting unit (first light-emitting unit) composed of a hole transport layer, a blue light-emitting layer, and an electron transport layer was formed on the hole injection layer. Specifically, the α-NPD was formed as a hole transport layer with a film thickness of 90 nm (deposition rate: 0.2 to 0.4 nm / sec) by a vacuum evaporation method. Subsequently, a blue light emitting layer was formed on the hole transport layer. A B-Host compound was used as the host of the light emitting layer, and a BD-1 compound was used as the dopant. Vacuum deposition was performed so that the added amount of the dopant was 5% in terms of the film thickness ratio to obtain a light emitting layer having a film thickness of 30 nm. Subsequently, EEL-1 was formed with a film thickness of 20 nm as EEL which is an electron carrying layer on the blue light emitting layer.
A charge generation layer was formed following the blue light emitting unit. On the EEL of the light emitting unit, a mixed layer of an electron injecting material Bphen and Li was formed as an N layer with a thickness of 10 nm, and HAT was formed as a P layer with a thickness of 10 nm.
Following the charge generation layer, a yellow light emitting unit (second light emitting unit) was formed. The formation method was the same as that of the blue light emitting unit described above. On the P layer of the charge generation layer, α-NPD was formed as a hole transport layer with a thickness of 60 nm (deposition rate: 0.2 to 0.4 nm / sec) by a vacuum evaporation method. Subsequently, a yellow light emitting layer was formed on the hole transport layer. CBP was used as the host of the yellow light emitting layer, and Ir (bzq) ₃ was used as the dopant. Vacuum deposition was performed so that the added amount of the dopant was 5% in terms of the film thickness ratio to obtain a light emitting layer having a film thickness of 30 nm.
Subsequently, BCP was formed with a thickness of 10 nm as a hole blocking layer on the yellow light emitting layer. ET-1 was formed to a thickness of 20 nm as an electron transport layer on the BCP.
Thereafter, LiF is formed with a film thickness of about 0.3 nm (deposition rate˜0.01 nm / sec) by a vacuum evaporation method, and then Al is formed with a film thickness of 200 nm by a vacuum evaporation method. To form an organic EL element.

The organic EL devices fabricated, and blue emission spectrum intensity ratio blue emission spectral intensity of Example 1 at a current density of 10MAcm ^-2, the relative value to the initial value of the blue emission spectrum after 300 hours of 50MAcm ^-2 driving It was measured.
Further, regarding the emission spectrum measured by the spectroradiometer, the distance (Δu ′) between the u′v ′ coordinate at 1000 nits and the u′v ′ coordinate at 1 nits in the CIE 1976 UCS chromaticity diagram (u′v ′ chromaticity diagram). The deviation of chromaticity was evaluated by the expression v ′). The results are shown in Table 1.

Example 2
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that EEL-2 was used as the EEL material. The results are shown in Table 1.

Example 3
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that EEL-3 was used as the EEL material. The results are shown in Table 1.

Example 4
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that EEL-4 was used as the EEL material. The results are shown in Table 1.

Example 5
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that EEL-5 was used as the EEL material. The results are shown in Table 1.

Example 6
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that BD-2 was used as a dopant for the blue light-emitting layer. The results are shown in Table 1.

Example 7
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that BD-2 was used as the dopant for the blue light-emitting layer, EEL-4 was used as the EEL material, and ET-2 was used as the electron injection material. . The results are shown in Table 1.

Example 8
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that BD-2 was used as the dopant of the blue light emitting layer, EEL-2 was used as the EEL material, and ET-2 was used as the electron injection material. . The results are shown in Table 1.

Comparative Example 1
ITO was formed to a thickness of 240 nm as an anode on a substrate made of a 30 mm × 30 mm glass plate. Next, a cell for an organic EL element in which a region other than the light emitting region of 2 mm × 2 mm was masked with an insulating film (not shown) by SiO ₂ vapor deposition was produced.
On the anode, hexanitrile azatriphenylene (HAT) having the above structure was formed as a hole injection layer with a thickness of 10 nm.
A blue light-emitting unit (first light-emitting unit) composed of a hole transport layer, a blue light-emitting layer, and an electron transport layer was formed on the hole injection layer. Specifically, the α-NPD was formed as a hole transport layer with a film thickness of 90 nm (deposition rate: 0.2 to 0.4 nm / sec) by a vacuum evaporation method. Subsequently, a blue light emitting layer was formed on the hole transport layer. B-Host compound was used for the host of the light emitting layer, and BD-1 was used for the dopant. Vacuum deposition was performed so that the added amount of the dopant was 5% in terms of the film thickness ratio to obtain a light emitting layer having a film thickness of 30 nm.
Next, EEL-2 was formed to a thickness of 20 nm as EEL as an electron transport layer on the blue light emitting layer. Furthermore, ET-1 was formed with a thickness of 20 nm as an electron transport layer on the EEL.
Thereafter, LiF is formed with a film thickness of about 0.3 nm (deposition rate˜0.01 nm / sec) by a vacuum evaporation method, and then Al is formed with a film thickness of 200 nm by a vacuum evaporation method. To form an organic EL element.
About the produced organic EL element, it evaluated similarly to Example 1. FIG. The results are shown in Table 1.

Comparative Example 2
ITO was formed to a thickness of 240 nm as an anode on a substrate made of a 30 mm × 30 mm glass plate. Next, a cell for an organic EL element in which a region other than the light emitting region of 2 mm × 2 mm was masked with an insulating film (not shown) by SiO ₂ vapor deposition was produced.
On the anode, hexanitrile azatriphenylene (HAT) having the above structure was formed as a hole injection layer with a thickness of 10 nm.
A yellow light emitting unit (first light emitting unit) composed of a hole transport layer, a blue light emitting layer, and an electron transport layer was formed on the hole injection layer. Specifically, the α-NPD was formed as a hole transport layer with a film thickness of 90 nm (deposition rate: 0.2 to 0.4 nm / sec) by a vacuum evaporation method. Subsequently, a yellow light emitting layer was formed on the hole transport layer. Vacuum deposition was performed so that the added amount of the dopant was 5% in terms of the film thickness ratio to obtain a light emitting layer having a film thickness of 30 nm. CBP was used as the host of the yellow light-emitting layer, and Ir (bzq) 3 was used as the dopant.
Following the yellow light-emitting unit, BCP was formed to a thickness of 10 nm as a hole blocking layer.
A charge generation layer was formed on the hole blocking layer. On the EEL of the light emitting unit, a mixed layer of an electron injecting material Bphen and Li was formed as an N layer with a thickness of 10 nm, and HAT was formed as a P layer with a thickness of 10 nm.
Following the charge generation layer, a blue light emitting unit was formed. The formation method was the same as that of the blue light emitting unit described above.
On the P layer of the charge generation layer, α-NPD was formed as a hole transport layer with a thickness of 60 nm (deposition rate: 0.2 to 0.4 nm / sec) by a vacuum evaporation method. Subsequently, a blue light emitting layer was formed on the hole transport layer.
B-Host compound was used for the host of the blue light emitting layer, and BD-1 was used for the dopant. Vacuum deposition was performed so that the added amount of the dopant was 5% in terms of the film thickness ratio to obtain a light emitting layer having a film thickness of 30 nm. Next, EEL-2 was formed to a thickness of 20 nm as EEL as an electron transport layer on the blue light emitting layer.
Next, ET-1 was formed to a thickness of 20 nm on the EEL.
Thereafter, LiF is formed with a film thickness of about 0.3 nm (deposition rate˜0.01 nm / sec) by a vacuum evaporation method, and then Al is formed with a film thickness of 200 nm by a vacuum evaporation method. To form an organic EL element.
About the produced organic EL element, it evaluated similarly to Example 1. FIG. The results are shown in Table 1.

Comparative Example 3
Comparative Example 3 does not use EEL, and a film thickness of α-NPD is 80 nm (deposition rate: 0.2 to 0.4 nm / sec) by vacuum evaporation as a hole transport layer on the P layer of the charge generation layer. A device configuration similar to that in Example 1 was prepared and evaluated except that the step was performed. The results are shown in Table 1.

  The B / Y (with EEL) structure, B monochromatic structure, Y / B structure, and B / Y (without EEL) structure in Table 1 are shown in Table 2. Each numerical value in Table 2 indicates a film thickness, and the unit is nm.

  In Example 1-8, an element with little chromaticity deviation was obtained.

  An organic EL element according to one embodiment of the present invention is used in display devices such as an organic EL panel module, display devices such as a television, a mobile phone, or a personal computer, and electronic equipment such as a light-emitting device for lighting or a vehicle lamp. Can be used.

Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will appreciate that these exemplary embodiments and / or embodiments are substantially without departing from the novel teachings and advantages of the present invention. It is easy to make many changes to the embodiment. Accordingly, many of these modifications are within the scope of the present invention.
All the contents of the Japanese application specification that is the basis of the priority of Paris in this application are incorporated herein.

Claims (29)

A first electrode;
A first light emitting unit disposed above the first electrode and having a first light emitting layer and an electron transport layer;
A charge generation layer disposed above the first light emitting unit;
A second light emitting unit disposed above the charge generation layer and having a second light emitting layer;
A second electrode disposed above the second light emitting unit,
The charge generation layer includes an N layer disposed on the first electrode side and a P layer disposed on the second electrode side, and the electron transport layer of the first light emitting unit is represented by the following formula (1). An organic electroluminescence device containing a compound.

(In Formula (1),
X ^{1 to} X ⁶ are each independently a nitrogen atom or CR. However, 1 to 4 of X ^{1 to} X ⁶ are nitrogen atoms.
Each R is independently a hydrogen atom, halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, sulfonyl group, mercapto group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphino group, substituted or unsubstituted Substituted acyl group, substituted or unsubstituted amino group, substituted or unsubstituted silyl group, substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, substituted Or an unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted ring forming carbon number An aryloxy group having 6 to 40, a substituted or unsubstituted heteroaryloxy group having 5 to 40 ring carbon atoms, substituted or unsubstituted, Substituted alkylthio groups having 1 to 30 carbon atoms, substituted or unsubstituted arylthio groups having 6 to 40 ring carbon atoms, substituted or unsubstituted heteroarylthio groups having 5 to 40 ring carbon atoms, substituted or unsubstituted An alkoxycarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryloxycarbonyl group having 6 to 40 ring carbon atoms, a substituted or unsubstituted heteroaryloxycarbonyl group having 5 to 40 ring carbon atoms, substituted or unsubstituted It is a group selected from the group consisting of a substituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms and a substituted or unsubstituted heterocyclic group having 5 to 40 ring atoms. The substituents may form a ring. ) The organic electroluminescence device according to claim 1, wherein the compound represented by the formula (1) is a compound represented by the following formula (2).

(In Formula (2),
X ^{1 to} X ⁶ are each independently a nitrogen atom, CR or CW.
However, at least one of X ^{1 to} X ⁶ is a nitrogen atom, and at least one of X ^{1 to} X ⁶ is CW.
R is the same as R in the formula (1).
W is a group represented by the following formula (11).
^Note, W is bound to any carbon atom of X 1 to X ^6. )

(In Formula (11),
a is an integer of 1 to 5. When a is 2 or more and 5 or less, Ar ¹ is the same or different from each other.
L ¹ is a single bond or a linking group, and the linking group in L ¹ is a substituted or unsubstituted C 1-30 linear, branched or cyclic polyvalent aliphatic hydrocarbon group, substituted Or an unsubstituted polyvalent amino group, a substituted or unsubstituted polyvalent aromatic hydrocarbon ring group having 6 to 40 ring carbon atoms, a substituted or unsubstituted polyvalent complex having 5 to 40 ring atoms. It is a polyvalent multiple linking group formed by bonding a cyclic group, or two or three groups selected from the aromatic hydrocarbon cyclic group and the heterocyclic group.
In the multiple linking group, the aromatic hydrocarbon ring group and the heterocyclic group constituting the multiple linking group are the same or different from each other, and the adjacent aromatic hydrocarbon ring group and the heterocyclic group are cyclic. May be formed.
Ar ¹ is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 40 ring atoms. However, at least one of Ar ¹ is a group represented by the following formula (21).
Ar ¹ and L ¹ may or may not form a ring structure. )

(In Formula (21),
X is NR, C (R) ₂ , an oxygen atom or a sulfur atom.
X ^{7 to} X ¹⁴ are each independently a nitrogen atom or CR.
R is the same as the formula (1).
However, the bond in the formula (21) means L ¹ in the formula (11) and is bonded to at least one of X and X ^{7 to} X ¹⁴ . )   The first light emitting unit includes a hole transport layer, the first light emitting layer in contact with the hole transport layer, and the electron transport layer in contact with the first light emitting layer in this order from the first electrode side. 3. The organic electroluminescence device according to 1 or 2.   The first electrode, a hole transport layer in contact with the first electrode, the first light emitting layer in contact with the hole transport layer, the electron transport layer in contact with the first light emitting layer, and the charge generation in contact with the electron transport layer The organic electroluminescent element in any one of Claims 1-3 which has a layer.   The organic electroluminescent element according to any one of claims 1 to 4, wherein a wavelength band of the first light emitting unit is 430 to 500 nm.   The organic electroluminescent element according to any one of claims 1 to 5, wherein an emission wavelength peak of the first light emitting unit is shorter than an emission wavelength peak of the second light emitting unit.   The organic electroluminescent element according to any one of claims 1 to 6, further comprising a third light emitting unit disposed above the second light emitting unit.   The organic electroluminescence device according to claim 7, wherein an emission wavelength peak of the first light emitting unit is shorter than an emission wavelength peak of the second light emitting unit and an emission wavelength peak of the third light emitting unit. The organic electroluminescent device according to any one of claims 1 to 8 X ¹ and X ³ is a nitrogen atom. A X ¹ and ^{X 3} is a nitrogen atom, an ^{X 5} is CH, ^{X 2} is ^{CR 11, X 4} is ^{CR 12,} a ^{group X 6} is represented by the formula (11),
R ¹¹ and R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 40 ring atoms. The organic electroluminescence device according to any one of claims 1 to 9. The organic electroluminescent device according to any one of claims 1~9 ^{X 1,} X ³ and ^{X 5} is a nitrogen atom. X ¹ , X ³ and X ⁵ are nitrogen atoms, X ² is CR ¹¹ , X ⁴ is CR ¹² and X ⁶ is a group represented by the formula (11),
R ¹¹ and R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 40 ring atoms. The organic electroluminescence device according to claim 11. X ¹ and ^{X 5} is a nitrogen atom, ^{X 3} is CH, ^{X 2} is ^{CR 11, X 4} is ^{CR 12,} a ^{group X 6} is represented by the formula (11),
R ¹¹ and R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 40 ring atoms. The organic electroluminescence device according to any one of claims 1 to 8. L ^{1 in the} formula (11) is a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 40 ring carbon atoms, or a substituted or unsubstituted trivalent aromatic group having 6 to 40 ring carbon atoms. It is a group hydrocarbon group, The organic electroluminescent element in any one of Claims 2-13.   The organic electroluminescence device according to claim 14, wherein the aromatic hydrocarbon group is a phenyl group.   The organic electroluminescence device according to claim 2, wherein X in the formula (21) is NR or an oxygen atom. The organic electroluminescence device according to claim 2, wherein X in the formula (21) is NR, and the R is connected to L ¹ .   The organic electroluminescence device according to claim 2, wherein a in the formula (11) is 1 or 2. The group represented by said Formula (11) is group represented by following formula (11-1), The organic electroluminescent element in any one of Claims 2-18.

(In Formula (11-1), L ¹ is the same as L ^{1 in} Formula (11).
n is each independently an integer of 0 to 4, and R ′ is independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms. Substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, substituted or unsubstituted aralkyl group having 6 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms, substituted or unsubstituted And an arylthio group having 6 to 20 ring carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 20 ring atoms. It is a group selected from the group. The substituents may form a ring. ) The group represented by said Formula (11) is a group represented by following formula (11-2), The organic electroluminescent element in any one of Claims 2-18.

(In Formula (11-2), L ¹ is the same as L ^{1 in} Formula (11).
n is each independently an integer of 0 to 4, and R ′ is independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms. Substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, substituted or unsubstituted aralkyl group having 6 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 20 ring carbon atoms, substituted or unsubstituted And an arylthio group having 6 to 20 ring carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 20 ring atoms. It is a group selected from the group. The substituents may form a ring. ) The organic electroluminescence device according to any one of claims 1 to 20, wherein the compound represented by the formula (1) is a compound represented by the following formula (11-3).

(In formula (11-3), X ² , X ⁵ and X ⁶ are the same as X ² , X ⁵ and X ^{6 in} formula (1), respectively.
Ar ^{1, L 1} and a are respectively the same as ^Ar 1, ^{L 1} and a in the formula (11).
B is a group selected from the following. Each of the bond hands of the group described below means a bond linking the carbon atom in formula (11-3) and B, and is bonded to any carbon atom constituting the selected group ( However, carbon atoms that cannot be bonded to hydrogen atoms are excluded).

  The organic electroluminescence device according to any one of claims 1 to 21, wherein the first light emitting layer contains an anthracene derivative as a host material. The organic electroluminescence device according to claim 22, wherein the anthracene derivative is a compound represented by the following formula (3).

(In Formula (3), B ₁ and B ₂ are each independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 20 ring carbon atoms,
R _{11 to} R ₁₈ are each independently a hydrogen atom, a fluorine atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted group. An alkylsilyl group having 3 to 30 carbon atoms, a substituted or unsubstituted arylsilyl group having 8 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted ring forming carbon It is an aryloxy group having 6 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms. )   The organic electroluminescence device according to any one of claims 1 to 23, wherein the N layer of the charge generation layer contains at least one of an electron donating metal, a metal compound, and a metal complex.   The organic electroluminescence device according to claim 24, wherein the N layer of the charge generation layer contains at least one of an alkali metal, an alkaline earth metal, a rare earth metal, a rare earth metal compound, and a rare earth metal complex. . The organic electroluminescence device according to any one of claims 1 to 25, wherein the N layer of the charge generation layer contains one or more compounds represented by the following formulas (I ') to (III').

[In formulas (I ′) to (III ′), R ^{1a to} R ^7a , R ^{1b to} R ^7b , and R ^{1c to} R ^6c each independently represents a hydrogen atom, a substituted or unsubstituted ring carbon number of 6 to 60 aryl groups, substituted or unsubstituted pyridyl groups, substituted or unsubstituted quinolyl groups, substituted or unsubstituted alkyl groups having 1 to 50 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 50 carbon atoms, A substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, a substituted or unsubstituted group Substituted with an arylthio group having 6 to 50 ring carbon atoms, a substituted or unsubstituted alkoxycarbonyl group having 2 to 50 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. Amino group, a halogen atom, a cyano group, a nitro group, a hydroxyl group or a carboxyl ^group, R ^1a to R ^7a, of R 1b ^{to R 7b} or ^R 1c ^{to R 6c,} those adjacent, taken together rings It may be formed.
L ^1a and L ^1b are each a single bond or a linking group.
Ar ^1a , Ar ^1b , Ar ^1c and Ar ^2c are each a substituted or unsubstituted aromatic group having 6 to 60 carbon atoms.
n is 1-4, and when n is 2 or more, the groups having a phenanthroline skeleton in parentheses may be the same or different. ] The organic electroluminescence device according to any one of claims 1 to 26, wherein the P layer of the charge generation layer contains one or more compounds represented by the following formula (III) or (IV).

(In the formula (III), R ^{1c to} R ^6c are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted group. A quinolyl group, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 ring carbon atoms, substituted or substituted Unsubstituted alkoxy group having 1 to 50 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, substituted or unsubstituted C2-C50 alkoxycarbonyl group, substituted or unsubstituted ring-substituted C6-C50 amino group, halogen atom, cyano group, nitro group Group, a hydroxyl group or a carboxyl group.)

[In Formula (IV), Rg ¹ and Rg ² may be the same as or different from each other, and are represented by the following Formula (i) or (ii).

(In formulas (i) and (ii), X ¹ and X ² may be the same or different from each other and are any of the divalent groups shown in the following formulas (a) to (g).)

(In formulas (a) to (g), R ^{21 to} R ²⁴ may be the same as or different from each other, and each represents a hydrogen atom, a substituted or unsubstituted fluoroalkyl group, a substituted or unsubstituted alkyl group, a substituted or (It is an unsubstituted aryl group or a substituted or unsubstituted heterocyclic group, and R ²² and R ²³ may be bonded to each other to form a ring.)
R ^{1 to} R ⁴ may be the same as or different from each other, and each represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted group Aryl group, substituted or unsubstituted heterocyclic group, halogen atom, substituted or unsubstituted fluoroalkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted fluoroalkoxy group, substituted or unsubstituted aryloxy group, substituted Or an unsubstituted aralkyloxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, or a cyano group, or R ¹ and R ² and R ³ and R ⁴ are bonded to each other to form a ring To do.
Y ^{1 to} Y ⁴ may be the same as or different from each other, and are N, CH, or C (R ⁵ ), and R ⁵ has the same meaning as R ^{1 to} R ⁴ . ]   A display device comprising two or more organic electroluminescence elements according to claim 1.   The electronic device carrying the organic electroluminescent element in any one of Claims 1-27.

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