JPS6025195A - El element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a single EL element that emits white light.

BACKGROUND ART AND PROBLEMS EL devices having ETJ elements that emit white light have been widely used as surface light sources, or there is no phosphor that emits white light by itself. For this reason, a mixture of fluorophores and fluorescent dyes is used as the luminescent material for white-emitting F3L elements.

As such a mixture, the blue-green luminescent ZnS:O
u(M (Ou and Ol or Zn added as an activator)
5o or less) and orange-emitting ZnS: OuM
Mixtures of fluorophores called n, and mixtures of ZnS:OuB, r, which are phosphors that emit green light, and Rhodamine B, which is a fluorescent dye that emits red light, are known.

However, when different types of phosphors are mixed, there are problems in that the color vJA of the light changes over time due to the difference in the lifespan of each phosphor, and the brightness is also low.

On the other hand, when %Zn8:0uBr and rhodamine B are mixed, there is a problem that only yellowish white light can be obtained instead of pure white light and the actual brightness is low.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide an FfL element that can obtain white light with good color purity and high brightness regardless of the passage of time.

Summary of the Invention The present invention relates to a single EL element containing a mixture of a green-emitting phosphor and Rhodamine 30G as a luminescent material in a luminescent layer.

EXAMPLE Hereinafter, an example of the present invention will be explained with reference to FIGS. 1 to 4.

FIG. 1 shows a flexible type ET device using the ET device according to the present invention. This flexible FfL device (11) consists of either an EL element (2) that is not shaped like a thin plate of approximately square shape, or two transparent moisture-proof films (3) that are approximately square and have a larger area than this 14L element (2). The entire I':TJ device 1t(1) has flexibility.

ETJ element (21 is a transparent polyester film (4)
) A transparent electrode (5) made of ITO is vacuum-deposited on top of the
have. A luminescent layer (6) in the form of a slurry is coated on the transparent electrode (5) to a thickness of 50 μm by screen printing, or this luminescent layer ((i) is dried by holding at 150 C for 6 minutes. Light emitting layer (6)
On top, the M foil is 100μm thick with a 180C heat roll.
It is thermocompressed to a thickness of
) on the back wi1 pole (which is a force).

Fs as a filler for the light emitting layer (6).
(50-95% by weight) and Rhodamine 30G (0,
A mixture of 01-[] and 11% by weight dispersed in a high dielectric constant binder (50-5% by weight) is used.

Rhodamine 60G, as shown by the following molecular formula, is a basic dye in which the carboxyl group of Rhodamine B is converted into a propyl ester, and is excited by light with a wavelength in the vicinity of 5000, and fluoresces strongly in orange. The above high @ electrical conductivity binder U, 41 fluoroethylene-
It is made of polyvinylidene fluoride, cyanoethyl cellulose, etc. Further, one light-emitting layer (6) may contain an appropriate amount of dimethylacetamide as a viscosity-adjusting solvent.

Note that the amounts of Ou and α added in Zn S r OuOl are 0.045 weight, it weight, and 0.020 weight weight, respectively.

The two moisture-proof films (3) cover both electrodes (5) (7).
FIL element (2) sandwiching E L element (2) from the side.
are thermocompressed together around the periphery. Since this thermocompression bonding is carried out in dry Ar or N2 gas, this dried 2 Ar-? N2 gas has been used for months. Moisture-proof film (3) For example, fluorohalocarbon film (for example, Aclar manufactured by Allied Chemical Company, USA), polychlorotribroroethylene film, etc. are used.

Electrode (5) (71 is the power supply for the outer lit (not shown)
Terminals (not shown) of leads (not shown) are pasted for connection to the film, and these leads extend outward from between the two moisture-proof films (3). .

Electrodes (5) (7) of the EL device (1) configured as above
) when an alternating current voltage is applied through a lead (not shown).

The light emitting layer (6) emits light. This light is transmitted through the transparent electrode (5),
The transparent polyester film (4) and the transparent moisture-proof film (3) are taken out through the passage, and the EL device # (1) is used as a surface light source.

Figure 2 shows the relationship between the wavelength and relative energy of light obtained by IJ.As is clear from Figure 2, the light emitted by the EL device (1) is
It has two peaks of relative energy at wavelengths near 0λ and near 5700i, but the former is ZnS:Ou(M
The latter is an orange light from Rhodamine 30G.

FIG. 6 is an xy chromaticity diagram showing the chromaticity points of the light shown in FIG. The chromaticity point of the light shown in Figure 2 is x = 0.5
486, y=0.3620, and as shown by the point X in FIG. 6, it is found that the white color is very pure.

Rhodamine 50G is excited by light with a wavelength of around 5000λ and fluoresces, but as is clear from Figure 2, the blue-green light produced by Zn8:Ou(M) has a relatively high relative energy at a wavelength around 5000A. The results show that rhodamine 3GG is effectively excited by blue-green light from ZnS:Ou(M) and emits light with high relative energy.

Figure 4 shows that the luminescent materials are ZnS: 0uOl and Zn8.
: l1i which is a mixture of fluorophores called OuMn
The luminance of light of the 3L device and the ET device (1) according to the present example is shown. In this figure 4, the frequency is I K
The results are shown when the voltage of the alternating current voltage of l(z) is changed to various values.
The case of an EL device using a mixture of iOuOl and ZnS:OuMn is shown, and the case of the EL device (1) according to the present example is shown using real rice. As mentioned above, rhodamine 6()G 11 Zn8:Ou(M) is effectively excited by the blue-green light and fluoresces strongly, so as is clear from FIG.
Device (1) can obtain high-intensity light even at low voltage.

Application Examples The present invention has been described based on one embodiment, but the present invention is not limited to this embodiment, and various modifications can be made. It is Noh.

For example, in the above example, Zn8:Ou(M) was used as the phosphor to be mixed with Rhodamine 60G, but if it is a phosphor that emits blue-green light, 1jZns+ou(M)
It may be something other than that.

Further, in the two-way embodiment, the present invention was applied to the 7 flexible type EL device (1), but the present invention can also be applied to EL devices other than the flexible type.

Further, in the above embodiment, the EL element (2) to which the present invention is applied is a single-sided light-emitting EL element in which only one electrode (5) is transparent.
The present invention can also be applied to a double-sided emitting EL device in which one or both electrodes are transparent.

Effects of the Invention As described above, in the EL device according to the present invention, a mixture of a phosphor that emits blue-green light and Rhodamine 30G is contained in the luminescent layer as a luminescent material. Since different types of phosphors are not mixed, white light with good color purity can be obtained regardless of the passage of time.

tyc and Rhodamine 3GG are excited by blue-green light and fluoresce strongly in orange, so high-intensity white light can be obtained even at low voltage.

[Brief Description of the Drawings] Fig. 1 is a schematic cross-sectional view showing a flexible hlL device using the EL element according to the present invention, and Fig. 2 shows the light obtained by the Ifl L device shown in Fig. 1. Figure 6 is a graph showing the xy chromaticity point of the light shown in Figure 2, Figure 4 is a graph showing the relationship between the wavelength and relative energy of As shown in 7'c
It is a graph showing the brightness of each light of the LL device. Regarding the symbols used in the drawings, (2)...
......Flt L element (5)...
・・・・・・Transparent electrode (6)・・・・・・・・・・・・
Light-emitting layer (force.........back electrode. Agents: Masaru Ueya, Yoshio Tsuneko I, Toshihiro Sugiura, Figure 1, Figure 2)

Claims (1)

[Claims] An EL single element in which a mixture of a phosphor that emits blue-green light and rhodamine 60G is contained in a luminescent layer as a luminescent material and 17.