JPH07150138A - Organic electroluminescent device - Google Patents
Organic electroluminescent deviceInfo
- Publication number
- JPH07150138A JPH07150138A JP5300455A JP30045593A JPH07150138A JP H07150138 A JPH07150138 A JP H07150138A JP 5300455 A JP5300455 A JP 5300455A JP 30045593 A JP30045593 A JP 30045593A JP H07150138 A JPH07150138 A JP H07150138A
- Authority
- JP
- Japan
- Prior art keywords
- light emitting
- electroluminescent device
- forming
- base material
- luminescent layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000463 material Substances 0.000 claims description 63
- 239000000126 substance Substances 0.000 claims description 15
- 150000001875 compounds Chemical class 0.000 claims description 4
- 125000000609 carbazolyl group Chemical class C1(=CC=CC=2C3=CC=CC=C3NC12)* 0.000 claims 3
- 238000002347 injection Methods 0.000 abstract description 15
- 239000007924 injection Substances 0.000 abstract description 15
- 239000000758 substrate Substances 0.000 abstract description 6
- 239000011521 glass Substances 0.000 abstract description 5
- 230000005525 hole transport Effects 0.000 abstract description 5
- FBTOLQFRGURPJH-UHFFFAOYSA-N 1-phenyl-9h-carbazole Chemical compound C1=CC=CC=C1C1=CC=CC2=C1NC1=CC=CC=C12 FBTOLQFRGURPJH-UHFFFAOYSA-N 0.000 abstract description 4
- 150000004985 diamines Chemical class 0.000 abstract description 2
- 238000001035 drying Methods 0.000 abstract description 2
- 229910052738 indium Inorganic materials 0.000 abstract description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 abstract description 2
- 229910052749 magnesium Inorganic materials 0.000 abstract description 2
- TVIVIEFSHFOWTE-UHFFFAOYSA-K tri(quinolin-8-yloxy)alumane Chemical compound [Al+3].C1=CN=C2C([O-])=CC=CC2=C1.C1=CN=C2C([O-])=CC=CC2=C1.C1=CN=C2C([O-])=CC=CC2=C1 TVIVIEFSHFOWTE-UHFFFAOYSA-K 0.000 abstract description 2
- 238000007740 vapor deposition Methods 0.000 abstract 3
- 239000002019 doping agent Substances 0.000 abstract 2
- QUPDWYMUPZLYJZ-UHFFFAOYSA-N ethyl Chemical compound C[CH2] QUPDWYMUPZLYJZ-UHFFFAOYSA-N 0.000 abstract 2
- 239000011159 matrix material Substances 0.000 abstract 2
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 abstract 2
- SILGFOROOQTULR-UHFFFAOYSA-N 9h-carbazole-3,6-dicarboximidamide Chemical compound C1=C(C(N)=N)C=C2C3=CC(C(=N)N)=CC=C3NC2=C1 SILGFOROOQTULR-UHFFFAOYSA-N 0.000 abstract 1
- -1 C6dH5 Chemical group 0.000 abstract 1
- 238000004140 cleaning Methods 0.000 abstract 1
- 238000005530 etching Methods 0.000 abstract 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 abstract 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 abstract 1
- 238000000034 method Methods 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 6
- 150000001716 carbazoles Chemical class 0.000 description 5
- 239000000969 carrier Substances 0.000 description 5
- 229910017911 MgIn Inorganic materials 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000005401 electroluminescence Methods 0.000 description 2
- 229910001316 Ag alloy Inorganic materials 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- JHYLKGDXMUDNEO-UHFFFAOYSA-N [Mg].[In] Chemical compound [Mg].[In] JHYLKGDXMUDNEO-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- QZPSXPBJTPJTSZ-UHFFFAOYSA-N aqua regia Chemical compound Cl.O[N+]([O-])=O QZPSXPBJTPJTSZ-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 239000003599 detergent Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 238000004770 highest occupied molecular orbital Methods 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000004768 lowest unoccupied molecular orbital Methods 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- SJCKRGFTWFGHGZ-UHFFFAOYSA-N magnesium silver Chemical compound [Mg].[Ag] SJCKRGFTWFGHGZ-UHFFFAOYSA-N 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
Landscapes
- Electroluminescent Light Sources (AREA)
- Luminescent Compositions (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、有機電界発光素子に関
し、詳しくはその発光層の改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device, and more particularly to improvement of its light emitting layer.
【０００２】[0002]
【従来の技術】近年、情報機器の多様化に伴って、ＣＲ
Ｔより低消費電力で空間占有容積の少ない平面表示素子
のニーズが高まっている。このような平面表示素子とし
ては、液晶、プラズマディスプレイ等があるが、特に、
最近は自己発光型で表示が鮮明な電界発光素子が注目さ
れている。2. Description of the Related Art In recent years, with the diversification of information equipment, CR
There is an increasing need for flat panel display devices that consume less power than T and occupy less space. Examples of such a flat display element include a liquid crystal display and a plasma display.
Recently, electroluminescent devices that are self-luminous and have a clear display have been receiving attention.
【０００３】ここで電界発光素子は、材料により無機電
界発光素子と有機電界発光素子とに大別でき、無機電界
発光素子は既に実用化されている。しかしながら、無機
電界発光素子の駆動方式は、高電界の印加によって加速
された電子が発光中心を衝突して発光させるという、所
謂「衝突励起型発光」であるため、高電圧で駆動させる
必要がある。このため、周辺機器の高コスト化を招来す
るという課題を抱えている。Here, the electroluminescent element can be roughly classified into an inorganic electroluminescent element and an organic electroluminescent element depending on the material, and the inorganic electroluminescent element has already been put into practical use. However, the driving method of the inorganic electroluminescence device is so-called "collision excitation type light emission" in which electrons accelerated by the application of a high electric field collide with the light emission center to emit light, and thus it is necessary to drive at a high voltage. . Therefore, there is a problem that the cost of the peripheral device is increased.
【０００４】これに対し、上記有機電界発光素子は、電
極から注入された電荷（ホール及び電子）が発光体中で
再結合して発光するという所謂「注入型発光」であるた
め、低電圧で駆動することができる。しかも有機化合物
の分子構造を変更することによって任意の発光色を容易
に得ることができるという利点もある。従って、有機電
界発光素子は、これからのディスプレイデバイスとして
非常に有望である。On the other hand, the above-mentioned organic electroluminescence device is a so-called "injection type light emission" in which electric charges (holes and electrons) injected from the electrode are recombined in the light emitting body to emit light, and therefore, at a low voltage. Can be driven. Moreover, there is an advantage that an arbitrary luminescent color can be easily obtained by changing the molecular structure of the organic compound. Therefore, the organic electroluminescent device is very promising as a display device in the future.
【０００５】上記したように、有機電界発光素子は発光
素子として様々な利点を有し、実用化が待ち望まれてい
るものの、さらに解決すべき課題を数多く有している。
その一つは、発光寿命が短いという点である。現在のと
ころ、有機電界発光素子の発光時間は１〜２千時間程度
であり、実用化のめどである１万時間に比べるとまだま
だ開きがある。これを解決する一つの方法として、発光
の高効率化が挙げられる。発光効率を上げることによっ
て、同じ輝度を得るのに、低い消費電力ですむことにな
り、その結果、発光の際にかかる素子への負担が軽くな
り、素子の劣化を抑えることができ、長寿命化を図るこ
とができるのである。As described above, the organic electroluminescent device has various advantages as a light emitting device, and although there are long-awaited practical applications, there are many problems to be solved.
One of them is that the emission life is short. Currently, emission time of the organic electroluminescent device is about 1 to 2 thousand hours, there is opened still compared to 10,000 hours a prospect of practical use. One way to solve this is to increase the efficiency of light emission. By increasing the luminous efficiency, it is possible to obtain the same brightness with low power consumption, and as a result, the burden on the element during light emission is reduced, deterioration of the element can be suppressed, and long life is achieved. It can be realized.
【０００６】素子の発光効率を上昇させる一つの方法と
して、発光材料の発光効率を上昇させる方法があげられ
る。従来から行われている発光材料の発光効率を上昇さ
せる方法として、以下にしめすようなドーピング法があ
る。この方法では、濃度の濃い状態、即ちそれ単独で発
光層を作製した場合は、濃度消光により発光しない材料
をドーピング材として、多量の母材に対して少量混ぜ込
んだものを発光層の材料とし、素子を作製するものであ
る。One method for increasing the luminous efficiency of the device is to increase the luminous efficiency of the light emitting material. As a conventional method for increasing the luminous efficiency of a light emitting material, there is a doping method as shown below. In this method, when the light emitting layer is produced in a high concentration state, that is, when the light emitting layer is produced by itself, a material that does not emit light due to concentration quenching is used as a doping material, and a material mixed in a small amount with a large amount of base material is used as a material for the light emitting layer. , To fabricate the device.
【０００７】この方法によれば、発光層中で、発光材料
の濃度は低濃度となり、発光を起こしやすい状態とな
る。これにより、それ単独で発光層を作製した場合は発
光しなかったものが発光するようになり、発光材料の発
光効率を上昇させることになる。According to this method, the concentration of the light emitting material in the light emitting layer is low, and light is easily emitted. As a result, when the light emitting layer is produced by itself, the light emitting layer emits light that does not emit light, thereby increasing the light emitting efficiency of the light emitting material.
【０００８】[0008]
【発明が解決しようとする課題】ところで、上記したよ
うな従来のドーピング法においては、母材としては、最
高被占軌道と最低空軌道との間のエネルギーギャップが
ドーピング材の最高被占軌道と最低空軌道との間のエネ
ルギーギャップより大きいものが用いられており、その
発光は、注入されたキャリアによって、励起された母材
からエネルギーギャップの小さいドーピング材にエネル
ギーが移動し、ドーピング材が励起され発光するという
ものである。By the way, in the conventional doping method as described above, the energy gap between the highest occupied orbital and the lowest unoccupied orbital is the base material and the highest occupied orbital of the doping material. A larger energy gap from the lowest unoccupied orbit is used, and the emitted light is excited by the injected carriers by transferring energy from the excited base material to the doping material with a small energy gap. It emits light.
【０００９】しかしながら、このドーピング法では、発
光するドーピング材の量は母材の量と比べてかなり少な
いため励起状態にある母材からドーピング材へのエネル
ギー移動が大量にあると、ドーピング材の光放射過程が
追いつかずに非放射失活する割合が多くなるという問題
があり、必ずしも素子の高効率化をはかる方法としては
有効なものではなかった。However, in this doping method, the amount of the doping material that emits light is considerably smaller than the amount of the base material, and therefore, if there is a large amount of energy transfer from the base material in an excited state to the doping material, There is a problem that the rate of non-radiative deactivation increases without catching up with the radiation process, which is not always an effective method for increasing the efficiency of the device.
【００１０】本発明は、上記問題点に鑑み行われたもの
であり、発光層を改良することによって、より高効率な
発光を呈する電界発光素子を提供することを目的とす
る。The present invention has been made in view of the above problems, and an object of the present invention is to provide an electroluminescent device which exhibits more highly efficient light emission by improving a light emitting layer.
【００１１】[0011]
【課題を解決するための手段】前記目的を達成するため
に、本発明はホール注入電極と電子注入電極との間にす
くなくとも発光層を有する有機電界発光素子において、
前記発光層が母材とドーピング材とを有しており、前記
ドーピング材がカルバゾール誘導体であり、前記母材に
用いられる材料の最高被占軌道と最低空軌道との間のエ
ネルギーギャップがカルバゾール誘導体の最高被占軌道
と最低空軌道との間のエネルギーギャップより小さいこ
とを特徴とする。In order to achieve the above-mentioned object, the present invention provides an organic electroluminescent device having at least a light emitting layer between a hole injecting electrode and an electron injecting electrode.
The light emitting layer has a base material and a doping material, the doping material is a carbazole derivative, and the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital of the material used for the base material is a carbazole derivative. Is smaller than the energy gap between the highest occupied orbit and the lowest unoccupied orbit.
【００１２】さらに、前記カルバゾール誘導体は前記化
１にしめされる化合物であることを特徴する。但し、前
記化１のＲは、Ｈ、ＣＨ3、 ＣＨ2 ＣＨ3 、ＣＨ（ＣＨ
3 ）2 、ＯＣＨ3 、Ｃ6 Ｈ5 、Ｃ6 Ｈ4 （ＣＨ3 ）、Ｃ
6 Ｈ4 （ＣＨ2 ＣＨ3 ）及びＣ6 Ｈ4（ＯＣＨ3 ）から
なる群から選択される。Further, the carbazole derivative is a compound represented by the chemical formula 1. However, R in the above chemical formula 1 is H, CH 3 , CH 2 CH 3 , CH (CH
3 ) 2 , OCH 3 , C 6 H 5 , C 6 H 4 (CH 3 ), C
It is selected from the group consisting of 6 H 4 (CH 2 CH 3 ) and C 6 H 4 (OCH 3 ).
【００１３】[0013]
【作用】本発明の素子は、以下ようにして発光している
と考えることができる。電極から注入されたキャリアに
よって、母材、ドーピング材のカルバゾール誘導体、い
ずれもが直接励起される。励起された母材は、そのまま
発光する。また、励起されたドーピング材からは、エネ
ルギーギャップの小さい母材へエネルギーの供給が起こ
り、母材は励起され、発光する。The element of the present invention can be considered to emit light as follows. Both the base material and the carbazole derivative of the doping material are directly excited by the carrier injected from the electrode. The excited base material emits light as it is. Further, energy is supplied from the excited doping material to the base material having a small energy gap, and the base material is excited and emits light.
【００１４】このように、母材の発光は、注入されたキ
ャリアによって直接母材が励起され発光するだけでな
く、キャリアによって励起されたドーピング材からのエ
ネルギー移動により、励起され発光が起こるので、注入
されたキャリアは効率よく発光に寄与したことになり、
発光の効率は、単独で層を作製した場合よりもさらに向
上すると考えられる。As described above, in the light emission of the base material, not only the base material is directly excited by the injected carriers to emit light, but also the energy transfer from the doping material excited by the carriers causes the light emission to occur. The injected carriers contributed to light emission efficiently,
It is considered that the efficiency of light emission is further improved as compared with the case where the layer is formed by itself.
【００１５】さらに、ドーピング材と比較して母材は多
量に存在するので、ドーピング材から母材へのエネルギ
ーの供給過剰状態は起こることなく、スムーズにエネル
ギー移動が起こる。従って、励起されたドーピング材と
母材との間のエネルギー移動の際に、エネルギーの損失
は起こることなく、効率よく母材の発光に用いられる。Further, since the base material is present in a large amount as compared with the doping material, the energy is smoothly transferred from the doping material to the base material without causing excessive supply of energy. Therefore, when the energy is transferred between the excited doping material and the base material, energy loss does not occur and the base material is efficiently used for light emission.
【００１６】[0016]
（実施例１）図１は、本発明の本発明の一例にかかる電
界発光素子の断面図である。図に表わすように本実施例
の電界発光素子はガラス基板１上に、ホール注入電極２
（厚み：１０００Å）と、有機ホール輸送層３（厚み：
５００Å）と、有機発光層４（厚み：５００Å）と、電
子注入電極５（厚み：２０００Å）とが順に形成され
た、ＳＨ−Ａ型構造を成している。尚、上記ホール注入
電極２および電子注入電極５には、それぞれリード線６
が接続されており、電極間に電圧を印加できるようにな
っている。(Embodiment 1) FIG. 1 is a sectional view of an electroluminescent device according to an example of the present invention. As shown in the figure, the electroluminescent device of this embodiment has a hole injection electrode 2 on a glass substrate 1.
(Thickness: 1000Å) and organic hole transport layer 3 (thickness:
500 Å), the organic light emitting layer 4 (thickness: 500 Å), and the electron injection electrode 5 (thickness: 2000 Å) are formed in this order to form an SH-A type structure. The hole injection electrode 2 and the electron injection electrode 5 have lead wires 6 respectively.
Are connected so that a voltage can be applied between the electrodes.
【００１７】上記ホール注入電極２の材料としてインジ
ウム−スズ酸化物（ＩＴＯ）が、有機ホール輸送層３の
材料としてはジアミン誘導体（ＴＰＤ 下記化２に示
す）が、有機発光層４の材料としてはドーピング材とし
て、下記化３に示すフェニルカルバゾールを１重量％含
むトリス（８−キノリノラト）アルミニウム錯体（下記
化４に示す 以下Ａｌｑ3 と称する）が、電子注入電極
５の材料としてマグネシウム−インジウム（ＭｇＩｎ）
合金（１０：１）が、それぞれ用いられている。Indium-tin oxide (ITO) is used as the material for the hole injecting electrode 2, a diamine derivative (TPD shown in the following chemical formula 2) is used as the material for the organic hole transport layer 3, and the organic light emitting layer 4 is used as the material. As a doping material, a tris (8-quinolinolato) aluminum complex containing 1% by weight of phenylcarbazole shown in Chemical Formula 3 below (hereinafter referred to as Alq 3 shown in Chemical Formula 4 below) is used as a material of the electron injection electrode 5, and magnesium-indium (MgIn )
Alloys (10: 1) are used respectively.
【００１８】[0018]
【化２】 [Chemical 2]
【００１９】[0019]
【化３】 [Chemical 3]
【００２０】[0020]
【化４】 [Chemical 4]
【００２１】上記のような構成の電界発光素子は、以下
のようにして作製した。先ず、一方の主表面にＩＴＯの
膜が形成されたガラス基板１を用意し、当該ガラス基板
１上のＩＴＯを王水でエッチングして、２ｍｍの幅のＩ
ＴＯのラインしを形成し、ホール注入電極２を作製し
た。次いで、ホール注入電極２が形成されたガラス基板
１を洗剤液、ＩＰＡの順に超音波洗浄した。これをよく
乾燥した後、１０-5Ｔｏｒｒの真空下で、ＴＰＤを蒸着
し、有機ホール輸送層３を作製した。続けて、有機ホー
ル輸送層３上にＡｌｑ3 （上記化４に示す）と、Ａｌｑ
3 に対して１重量％の割合のフェニルカルバゾール（上
記化３に示す）とを共蒸着させ、有機発光層４を作製し
た。次に、有機発光層４上にマグネシウムとインジウム
を１０：１の割合で共蒸着し、電子注入電極５を作製し
た。最後に各電極にリード線６を取りつけた。The electroluminescent device having the above structure was manufactured as follows. First, a glass substrate 1 having an ITO film formed on one of its main surfaces is prepared, and the ITO on the glass substrate 1 is etched with aqua regia to remove I having a width of 2 mm.
A line for TO was formed to fabricate the hole injection electrode 2. Next, the glass substrate 1 on which the hole injection electrode 2 was formed was ultrasonically cleaned in the order of a detergent liquid and IPA. After drying this well, TPD was vapor-deposited under a vacuum of 10 −5 Torr to prepare an organic hole transport layer 3. Subsequently, Alq 3 (shown in Chemical Formula 4 above) on the organic hole transport layer 3 and Alq 3
The organic light emitting layer 4 was produced by co-evaporating 1% by weight of phenylcarbazole (shown in Chemical Formula 3 above) with respect to 3. Next, magnesium and indium were co-evaporated on the organic light emitting layer 4 at a ratio of 10: 1 to prepare the electron injection electrode 5. Finally, the lead wire 6 was attached to each electrode.
【００２２】このように作製した素子を、以下（ａ1 ）
素子と称する。 （実施例２）ドーピング材として、下記化５に示す化合
物を用いた以外は、上記実施例１と同様に素子の作製を
行なった。The element thus manufactured is represented by the following (a 1 )
It is called an element. (Example 2) An element was prepared in the same manner as in Example 1 except that the compound shown in Chemical formula 5 below was used as a doping material.
【００２３】[0023]
【化５】 [Chemical 5]
【００２４】このように作製された素子を、以下
（ａ2 ）素子と称する。 （比較例）発光層の材料として、ドーピング材を添加し
ないでＡｌｑ3 のみを用いた以外は、上記実施例と同様
に素子の作製を行なった。このように作製した素子を、
以下（ｘ）素子と称する。The element thus manufactured is hereinafter referred to as a (a 2 ) element. (Comparative Example) An element was manufactured in the same manner as in the above-described example except that Alq 3 was used as the material of the light emitting layer without adding a doping material. The device manufactured in this way is
Hereinafter referred to as (x) element.
【００２５】（実験）上記実施例の（ａ1 ）、（ａ2 ）
素子、比較例の（ｘ）素子を用いて、素子を発光させた
際の、輝度−電圧特性、輝度−電流密度特性、最高輝度
および最高発光効率をしらべたので、その結果を図２、
３、表１に示す。(Experiment) (a 1 ) and (a 2 ) of the above embodiment
The element, the (x) element of the comparative example, was used to examine the luminance-voltage characteristics, the luminance-current density characteristics, the maximum luminance and the maximum luminous efficiency, and the results are shown in FIG.
3, shown in Table 1.
【００２６】[0026]
【表１】 [Table 1]
【００２７】先ず、図２の輝度−電圧特性から明らかな
ように、本発明の素子は発光開始がより低電圧で起こっ
ている。また、図３の輝度−電流密度特性から明らかな
ように、本発明の素子は比較例の素子と比べて、同じ輝
度を得るのに、より低い電流でよいことがわかる。ま
た、表１から明らかなように、本発明の素子は、最高輝
度、最高発光効率いづれについても、比較例より高い値
をしめした。First, as is clear from the luminance-voltage characteristics of FIG. 2, in the device of the present invention, light emission starts at a lower voltage. Further, as is clear from the luminance-current density characteristics of FIG. 3, it can be seen that the element of the present invention requires a lower current to obtain the same luminance as the element of the comparative example. Further, as is clear from Table 1, the device of the present invention showed higher values than the comparative example in terms of maximum luminance and maximum luminous efficiency.
【００２８】上記のような実験結果から、本発明の素子
は、高い発光効率を持つことがわかった。 （その他の事項） ド−ピング材として用いる化合物は上記実施例で用
いたものに限ることはなく、これ以外のカルバゾ−ル誘
導体も用いることができる。 本実施例では、素子の構造としてＳＨ−Ａ型構造の
みについて示したが、両電極間に発光層のみが存在する
構造、ＳＨ−Ｂ型構造、ＤＨ型構造でもよい。 ホール注入電極の材料としては、仕事関数が高く、
透明性の高いものが望ましく、上記ＩＴＯの他に、金の
半透明膜を用いることができる。 電子注入電極の材料としては、仕事関数の低いこと
が要求され、上記ＭｇＩｎ合金の他に、マグネシウム−
銀合金、アルミニウム、カルシウム等が用いられる。From the above experimental results, it was found that the device of the present invention has high luminous efficiency. (Other Matters) The compound used as the doping material is not limited to the one used in the above examples, and other carbazole derivatives can also be used. Although only the SH-A type structure is shown as the structure of the device in this example, a structure in which only a light emitting layer exists between both electrodes, an SH-B type structure, or a DH type structure may be used. The material of the hole injection electrode has a high work function,
A material having high transparency is desirable, and a semitransparent film of gold can be used in addition to the above ITO. The material for the electron injection electrode is required to have a low work function. In addition to the above MgIn alloy, magnesium-
Silver alloy, aluminum, calcium, etc. are used.
【００２９】[0029]
【発明の効果】以上説明したように、本発明によれば、
母材が注入されたキャリアにより直接励起され、発光す
るだけでなく、励起したフェニルカルバゾール誘導体か
ら母材へのエネルギー移動が起こることによって励起さ
れ、発光するので、母材に用いた材料を単独に用いて発
光層とした場合より発光効率は上昇する。As described above, according to the present invention,
The base material is not only directly excited by the injected carriers to emit light, but also excited by the energy transfer from the excited phenylcarbazole derivative to the base material and emits light. The luminous efficiency is higher than that of the case where the luminous layer is used.
【００３０】また、励起されたドーピング材から母材へ
のエネルギー移動は、少量のドーピング材から多量な母
材へのエネルギーが移動するため、エネルギーの過剰供
給がおこることがなく、ドーピング材からのエネルギー
は有効に発光に使われる。以上のことから、本発明の電
界発光素子は、発光効率が高く、従って、発光素子の長
寿命化をはかることができると考えられる。In the energy transfer from the excited doping material to the base material, energy is transferred from a small amount of the doping material to a large amount of the base material, so that excessive supply of energy does not occur and the energy from the doping material is not supplied. Energy is effectively used for light emission. From the above, it is considered that the electroluminescent device of the present invention has high luminous efficiency, and thus can prolong the life of the light emitting device.
【図１】本発明の一例にかかる実施例の電界発光素子の
断面図である。FIG. 1 is a cross-sectional view of an electroluminescent device of an example according to an example of the present invention.
【図２】本実施例の（ａ1 ）、（ａ2 ）素子、比較例の
（ｘ）素子の輝度−電圧特性を示すグラフである。FIG. 2 is a graph showing luminance-voltage characteristics of the (a 1 ), (a 2 ) elements of this example and the (x) element of a comparative example.
【図３】本実施例の（ａ1 ）、（ａ2 ）素子、比較例の
（ｘ）素子の輝度−電流密度特性を示す図である。FIG. 3 is a diagram showing luminance-current density characteristics of (a 1 ), (a 2 ) elements of this example and (x) element of a comparative example.
２ ホール注入電極 ４ 有機発光層 ５ 電子注入電極 2 hole injection electrode 4 organic light emitting layer 5 electron injection electrode
───────────────────────────────────────────────────── フロントページの続き (72)発明者 浜田 祐次 守口市京阪本通２丁目５番５号 三洋電機 株式会社内 (72)発明者 柴田 賢一 守口市京阪本通２丁目５番５号 三洋電機 株式会社内 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yuji Hamada 2-5-5 Keihan Hondori, Moriguchi Sanyo Electric Co., Ltd. (72) Inventor Kenichi Shibata 2-5-5 Keihan Hondori, Moriguchi Sanyo Denki Within the corporation
Claims (2)
すくなくとも発光層を有する有機電界発光素子におい
て、前記発光層が母材とドーピング材とを有しており、
前記ドーピング材がカルバゾール誘導体であり、前記母
材に用いられる材料の最高被占軌道と最低空軌道との間
のエネルギーギャップがカルバゾール誘導体の最高被占
軌道と最低空軌道との間のエネルギーギャップより小さ
いことを特徴とする電界発光素子。1. An organic electroluminescent device having a light emitting layer at least between a hole injecting electrode and an electron injecting electrode, wherein the light emitting layer has a base material and a doping material,
The doping material is a carbazole derivative, and the energy gap between the highest occupied orbital and the lowest unoccupied orbital of the material used for the base material is more than the energy gap between the highest occupied orbital and the lowest unoccupied orbital of the carbazole derivative. An electroluminescent device characterized by being small.
す化合物であることを特徴とする請求項１記載の電界発
光素子。 【化１】 上記化１のＲは、Ｈ、ＣＨ3、ＣＨ2 ＣＨ3 、ＣＨ（Ｃ
Ｈ3 ）2 、ＯＣＨ3 、Ｃ6 Ｈ5 、Ｃ6 Ｈ4 （ＣＨ3 ）、
Ｃ6 Ｈ4 （ＣＨ2 ＣＨ3 ）及びＣ6 Ｈ4 （ＯＣＨ3 ）か
らなる群から選択される。2. The electroluminescent device according to claim 1, wherein the carbazole derivative is a compound represented by the following chemical formula 1. [Chemical 1] R in the above chemical formula 1 is H, CH 3 , CH 2 CH 3 , CH (C
H 3) 2, OCH 3, C 6 H 5, C 6 H 4 (CH 3),
C 6 H 4 (CH 2 CH 3) is selected from the group consisting of and C 6 H 4 (OCH 3) .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30045593A JP3443145B2 (en) | 1993-11-30 | 1993-11-30 | Organic electroluminescent device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30045593A JP3443145B2 (en) | 1993-11-30 | 1993-11-30 | Organic electroluminescent device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07150138A true JPH07150138A (en) | 1995-06-13 |
| JP3443145B2 JP3443145B2 (en) | 2003-09-02 |
Family
ID=17885005
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30045593A Expired - Fee Related JP3443145B2 (en) | 1993-11-30 | 1993-11-30 | Organic electroluminescent device |
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| Country | Link |
|---|---|
| JP (1) | JP3443145B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006151979A (en) * | 2004-11-29 | 2006-06-15 | Samsung Sdi Co Ltd | Phenylcarbazole-based compound and method for producing the same and organic electroluminescent device |
| US7201974B2 (en) | 2000-10-31 | 2007-04-10 | Sanyo Electric Co., Ltd. | Organic electroluminescence element |
| CN100357271C (en) * | 2005-06-22 | 2007-12-26 | 中国科学院长春应用化学研究所 | Hole transport materials with 9-phenyl carbazole as core and process for making same |
| US7678472B2 (en) | 2005-02-05 | 2010-03-16 | Au Optronics Corp. | Compound and organic light-emitting diode and display utilizing the same |
| US8021765B2 (en) | 2004-11-29 | 2011-09-20 | Samsung Mobile Display Co., Ltd. | Phenylcarbazole-based compound and organic electroluminescent device employing the same |
| US8188315B2 (en) | 2004-04-02 | 2012-05-29 | Samsung Mobile Display Co., Ltd. | Organic light emitting device and flat panel display device comprising the same |
-
1993
- 1993-11-30 JP JP30045593A patent/JP3443145B2/en not_active Expired - Fee Related
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|---|---|---|---|---|
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| US9478754B2 (en) | 2004-04-02 | 2016-10-25 | Samsung Display Co., Ltd. | Phenylcarbazole-based compounds and fluorene-based compounds and organic light emitting device and flat panel display device comprising the same |
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| US10573821B2 (en) | 2004-04-02 | 2020-02-25 | Samsung Display Co., Ltd. | Phenylcarbazole-based compounds and fluorene-based compounds and organic light emitting device and flat panel display device comprising the same |
| US10211406B2 (en) | 2004-04-02 | 2019-02-19 | Samsung Display Co., Ltd. | Phenylcarbazole-based compounds and fluorene-based compounds and organic light emitting device and flat panel display device comprising the same |
| US9917258B2 (en) | 2004-04-02 | 2018-03-13 | Samsung Display Co., Ltd. | Phenylcarbazole-based compounds and fluorene-based compounds and organic light emitting device and flat panel display device comprising the same |
| US8188315B2 (en) | 2004-04-02 | 2012-05-29 | Samsung Mobile Display Co., Ltd. | Organic light emitting device and flat panel display device comprising the same |
| US8974922B2 (en) | 2004-04-02 | 2015-03-10 | Samsung Display Co., Ltd. | Phenylcarbazole-based compounds and fluorene-based compounds and organic light emitting device and flat panel display device comprising the same |
| US8021765B2 (en) | 2004-11-29 | 2011-09-20 | Samsung Mobile Display Co., Ltd. | Phenylcarbazole-based compound and organic electroluminescent device employing the same |
| JP2006151979A (en) * | 2004-11-29 | 2006-06-15 | Samsung Sdi Co Ltd | Phenylcarbazole-based compound and method for producing the same and organic electroluminescent device |
| US8021764B2 (en) | 2004-11-29 | 2011-09-20 | Samsung Mobile Display Co., Ltd. | Phenylcarbazole-based compound and organic electroluminescent device employing the same |
| JP4589223B2 (en) * | 2004-11-29 | 2010-12-01 | 三星モバイルディスプレイ株式會社 | Phenylcarbazole compound, method for producing the same, and organic electroluminescent device |
| US7678472B2 (en) | 2005-02-05 | 2010-03-16 | Au Optronics Corp. | Compound and organic light-emitting diode and display utilizing the same |
| CN100357271C (en) * | 2005-06-22 | 2007-12-26 | 中国科学院长春应用化学研究所 | Hole transport materials with 9-phenyl carbazole as core and process for making same |
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