JP2004043646A5

JP2004043646A5 -

Info

Publication number: JP2004043646A5
Application number: JP2002203326A
Authority: JP
Filing date: 2002-07-11
Publication date: 2004-12-24
Anticipated expiration: 2022-07-11

Description

【００６７】
この発明による有機ＥＬ素子の使用方法について説明すると、この発明の有機ＥＬ素子は、用途に応じて、比較的高電圧のパルス性電圧を間欠的に印加するか、あるいは、比較的低電圧の非パルス性電圧（通常、２乃至５０Ｖ）を連続的に印加して駆動する。この発明の有機ＥＬ素子は、陽極の電位が陰極より高いときにのみ発光する。したがって、この発明の有機ＥＬ素子へ印加する電圧は直流であっても交流であってもよく、また、印加する電圧の波形、周期も適宜のものとすればよい。交流を印加すると、この発明の有機ＥＬ素子は、原理上、印加する交流の波形及び周期に応じて輝度が増減したり点滅を繰り返す。図１に示す有機ＥＬ素子の場合、陽極２と陰極６との間に電圧を印加すると、陽極２から注入された正孔が正孔注入／輸送層３を経て発光層４へ、また、陰極６から注入された電子が電子注入／輸送層５を経て発光層４へそれぞれ到達する。その結果、発光層４において正孔と電子との再結合が生じ、それにより生じた励起状態のゲスト化合物から目的とする発光が陽極２及び基板１を透過して放出されることとなる。この発明の有機ＥＬ素子は、クマリン誘導体と組み合わせて用いるホスト化合物とゲスト化合物の構造、配合割合などにもよるけれども、例えば、波長５８０乃至７３０ｎｍの赤色域で発光するものの場合、その色度は、通常、国際照明委員会（ＣＩＥ）によるｘｙ色度図上において、ｘが０．３５乃至０．７３の範囲、好ましくは、０．５５乃至０．６５の範囲に、また、ｙが０．１０乃至０．４５の範囲、好ましくは、０．３５乃至０．４２の範囲にある。[0067]
A method of using the organic EL device according to the present invention will be described. The organic EL device according to the present invention intermittently applies a relatively high voltage pulse voltage or a relatively low voltage non-voltage according to the application. A pulse voltage (usually 2 to 50 V) is applied continuously and driven. The organic EL device of the present invention emits light only when the potential of the anode is higher than that of the cathode. Therefore, the voltage applied to the organic EL element of the present invention may be direct current or alternating current, and the waveform and period of the applied voltage may be appropriately set. When an alternating current is applied, the organic EL element of the present invention, in principle, repeatedly increases and decreases in luminance or blinks according to the waveform and period of the applied alternating current. In the case of the organic EL element shown in FIG. 1, when a voltage is applied between the anode 2 and the cathode 6, holes injected from the anode 2 pass through the hole injecting / transporting layer 3 to the light emitting layer 4 or the cathode. Electrons injected from 6 reach the light emitting layer 4 through the electron injecting / transporting layer 5 respectively. As a result, recombination of holes and electrons occurs in the light emitting layer 4, and the target light emission from the excited guest compound produced thereby is emitted through the anode 2 and the substrate 1. The organic EL device of the present invention depends on the structure, mixing ratio and the like of the host compound and guest compound used in combination with the coumarin derivative, but in the case of light emitting in the red region of wavelength 580 to 730 nm, its chromaticity is Usually, on the xy chromaticity diagram according to the International Commission on Illumination (CIE), x is in the range of 0.35 to 0.73, preferably in the range of 0.55 to 0.65, and y is 0.10. To 0.45, preferably in the range of 0.35 to 0.42.

【００７０】
【実施例１】
〈有機ＥＬ素子用発光補助剤〉
反応容器にＮ，Ｎ−ジメチルホルムアミド１７ｍｌをとり、化学式２９で表される化合物２．７ｇと化学式３０で表される化合物２．４ｇとを加えた後、１．５時間加熱還流して反応させた。反応混合物を周囲温度まで冷却し、析出した結晶を濾取し、クロロホルム／メタノール混液により再結晶したところ、化学式１で表されるクマリン誘導体の橙色結晶が２．１ｇ得られた。[0070]
[Example 1]
<Light-emitting assistant for organic EL devices>
In a reaction vessel, 17 ml of N, N-dimethylformamide is taken, 2.7 g of the compound represented by the chemical formula 29 and 2.4 g of the compound represented by the chemical formula 30 are added, and then heated under reflux for reaction for 1.5 hours The The reaction mixture was cooled to ambient temperature, and the precipitated crystals were collected by filtration and recrystallized with a chloroform / methanol mixed solution to obtain 2.1 g of orange crystals of the coumarin derivative represented by Chemical Formula 1.

【００７６】
【実施例２】
〈有機ＥＬ素子用発光補助剤〉
反応容器にＮ，Ｎ−ジメチルホルムアミド６０ｍｌをとり、化学式３１で表される化合物８．１ｇと化学式３０で表される化合物６．８ｇとを加えた後、３時間加熱還流して反応させた。反応混合物を周囲温度まで冷却し、析出した結晶を濾取し、クロロホルム／メタノール混液により再結晶したところ、化学式２で表されるクマリン誘導体の橙色結晶が５．８ｇ得られた。[0076]
Second Embodiment
<Light-emitting assistant for organic EL devices>
In a reaction vessel, 60 ml of N, N-dimethylformamide was taken, 8.1 g of a compound represented by Chemical Formula 31 and 6.8 g of a compound represented by Chemical Formula 30 were added, and then heated under reflux for reaction for 3 hours. The reaction mixture was cooled to ambient temperature, and the precipitated crystals were collected by filtration and recrystallized with a chloroform / methanol mixed solution to obtain 5.8 g of orange crystals of a coumarin derivative represented by Chemical Formula 2.