JP2002171018A - Light-emitting device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve laser action from an organic solid material by improving stability in an organic molecule under high current injection, and by reducing excitation energy threshold. SOLUTION: Thin films 4 and 5 are laminated on a glass substrate 3. In the thin films, a metal fine particle 11 manufactured by the sol-gel method, and an organic fluorescent dye 19 are doped separately and independently. By resonance excitation in the surface plasmon of the metal fine particle 11, the light emission of the organic fluorescent dye 19 is reinforced cooperatively, thus reducing the excitation energy threshold of the laser oscillation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device for realizing an organic thin film laser and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, ultrafine particle dispersion glass of metal or semiconductor has a large nonlinear optoelectronic characteristic when the host glass is transparent and the particle diameter of the particles is sufficiently smaller than the wavelength of light. Attention has been paid to the electron tunneling phenomenon, and application studies on high-speed optical devices, quantum dot lasers, and the like have been actively conducted to apply these nonlinear optoelectronic characteristics to optical devices. Examples thereof include a method for producing ultrafine metal particles dispersed glass by a vapor phase synthesis method disclosed in JP-A-2-44031, and a non-linear optoelectronic material for ultrafine particles dispersed cadmium sulfide quantized by sol-gel method disclosed in JP-A-1-79038. Production. These conventional techniques make use of the characteristics of the ultrafine particles of the quantized metal or semiconductor, but do not utilize the effect of interaction with the surroundings.

On the other hand, glass materials in which organic molecules having various optical functions are dispersed have attracted attention as organic / inorganic hybrid optoelectronic materials, and are expected to be applied to organic thin-film lasers and the like. In order to realize a laser action from an organic solid material, it is important to improve the stability of organic molecules under high current injection and to lower the excitation energy threshold.

[0004]

In view of the above problems, in order to realize the application of a glass thin film to an organic thin film laser, a light emitting device in which a film doped with an organic fluorescent dye and metal fine particles is formed on a substrate has been developed. As proposed by the inventor, it is necessary to further reduce the threshold value of the excitation energy by using an interaction effect between metal fine particles having nonlinear optoelectronic characteristics and organic molecules having an optical function. Therefore, an object of the present invention is not only to lower the threshold value of the excitation energy but also to achieve high-efficiency light emission amplification by using the interaction effect with an organic molecule having a light function.

[0005]

The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

That is, in the first aspect, in a light emitting device having a layered film formed on a substrate, a film containing metal fine particles is formed on the substrate, and a film containing an organic fluorescent dye is formed thereon and laminated.

According to a second aspect, in the light emitting device according to the first aspect, the metal of the metal fine particles is gold (Au).

According to a third aspect, in the light emitting device according to the first aspect, the organic fluorescent dye is rhodamine B (rhodamin B).
e B).

In a fourth aspect, in the light emitting device according to the first aspect, the organic fluorescent dye is coumarin.

According to a fifth aspect of the present invention, in the light emitting device according to any one of the first to fourth aspects, at least one of the films is a silica (SiO ₂ ) / titania (TiO ₂ ) thin film.

According to a sixth aspect, in the light emitting device according to the first aspect, the light emitting element is used as an optical device material.

According to a seventh aspect, in the light emitting device according to the first aspect, the light emitting element is used as a laser material.

According to the present invention, in a light emitting device having a layered film formed on a substrate, (1) a film forming step of forming a film containing metal ions on the substrate, and (2) selecting metal ions in the thin film. A selective reduction process of forming a light emitting region by forming a metal fine particle by performing specific reduction, and (3) a film forming process of forming a film containing an organic fluorescent dye on a substrate were sequentially performed.

According to a ninth aspect of the present invention, in the method of manufacturing a light emitting device, at least one of the film forming processes includes a silica (SiO ₂ ) / titania (TiO ₂ ) precursor sol solution containing an organic luminescent dye, or Silica containing metal ions (SiO ₂ )
A film was formed by a sol-gel method using a sol solution of a / titania (TiO ₂ ) precursor.

[0015]

Next, embodiments of the present invention will be described. FIG. 1 is a flowchart showing an overall flow of a method for manufacturing a light emitting device according to the present invention, FIG. 2 is a diagram showing a flow of a film forming process, and FIG. 3 is a schematic sectional view in which a gel film is also dipped on a substrate. FIG. 4 is a schematic cross-sectional view in which a metal fine particle-doped thin film is formed on a substrate. 5 is an explanatory diagram of a selective reduction process using a photomask, FIG. 6 is an explanatory diagram of a selective reduction process using a spot beam, FIG. 7 is an explanatory diagram of a selective reduction process using an atomic force microscope, and FIG. FIG. 3 is a view showing a light emitting device after a selective reduction process. FIG. 9 is a cross-sectional view schematically showing one example of a longitudinal section of the light emitting device according to the present invention, and FIG. 10 is a schematic diagram of a fluorescent image obtained by observing the light emitting device with a fluorescent microscope. FIG. 11 is a cross-sectional view schematically showing an example of a vertical cross section of a light emitting device doped only with an organic light emitting device. FIG.
FIG. 13 is a cross-sectional view schematically showing an example of a longitudinal section when the light emitting device according to the present invention is optically excited, FIG. 13 is a view showing a mechanism of the laser oscillation enhancing action of the organic fluorescent dye, and FIG. FIG. 15 is a diagram showing the oscillation intensity of such a light emitting device, FIG. 15 is a diagram showing the relationship between the oscillation intensity and the excitation energy of the light emitting device according to the present invention and a light emitting device doped only with an organic fluorescent dye, and FIG. It is a figure which shows the fluorescence of rhodamine.

First, a method for manufacturing a light emitting device according to the present invention will be described. The overall flow of the manufacturing method will be described with reference to the flowchart shown in FIG. In this example, a fluid sol is prepared by hydrolyzing a metal alkoxide or the like, and the sol is heated and dried, and gelled by dehydration condensation to produce glass or the like. A film is formed on a glass substrate by using a sol-gel method. However, the film forming method is not limited to the sol-gel method, and another film forming method may be adopted.

First, a precursor sol solution containing metal ions is prepared (31). The process of forming a gel film (32) from the precursor sol solution (31) via the sol solution (36) is shown in the flow chart of FIG.

As the precursor sol solution (31), FIG.
As shown in, chloroauric acid is a metal ion source (HAuCl ₄ · 4
H ₂ O) in ethanol (0.05 M), Si (OC ₂ H ₅ ) ₄ and Ti (OC ₂ H ₅ ) _{4 as} the main components of the film, and HCl as the acid catalyst
/ H ₂ O is added. Note that Si
The ratio (Si / Ti) of silicon and titanium contained in (OC ₂ H ₅ ) ₄ and Ti (OC ₂ H ₅ ) ₄ is preferably, for example, about 2/1. Then, the precursor sol solution (31) adjusted as described above is hydrolyzed to produce a silica (SiO ₂ ) / titania (TiO ₂ ) sol solution (36). In this embodiment, gold is used as the metal, but the metal is not limited to gold, and another metal may be used.

The glass substrate 3 is immersed in the sol solution (36) prepared as described above to apply (dip coat) the sol solution to the glass substrate 3, and then thermally dehydrated and condensed (for example, at 150 ° C. for 1 minute). By heating, the sol solution is gelled, and as shown in FIG.
a is generated (32). The thickness of the gel film 4a is, for example, about 0.1 to 1 μm, but can be increased to a desired thickness by repeating dip coding or the like.

As described above, by forming a film by a sol-gel method using a silica / titania precursor sol solution, the film formation process can be performed at a low temperature. it can. Further, the metal ions can be arranged almost uniformly in the film. Therefore, in the present embodiment, the metal fine particles can be arranged almost uniformly in the form of a gel film. Although the silica / titania precursor is used as the sol solution, a silica precursor or a titania precursor containing the organic fluorescent dye 19 and a metal ion may be used alone.

Next, the metal ions present in the gel film 4a formed as described above are reduced to form light emitting regions 9 as metal fine particles. Here, the light emitting region 9 is a region where the metal fine particles are present, and the region where the metal fine particles are not present is the non-light emitting region 7 because the metal ions quench the fluorescence of the organic fluorescent dye. Hereinafter, the one in which the light emitting region 9 is formed on the gel film 4a in this manner is referred to as a metal fine particle-doped thin film 4.

In order to form the light emitting region 9 and the non-light emitting region 7 on the gel film 4a, as shown in FIG.
Must be selectively present (hereinafter, referred to as selective reduction), and in the non-light-emitting region 7, the metal ions 13 must remain in the gel film 4 a as they are. Then, as examples of the method of selective reduction, the following (A) and (B)
And (C).

(A) Photomask As shown in FIG. 5, a photomask 15 in which a pattern corresponding to the light emitting region 9 is formed in advance is brought close to the gel film 4a of the light emitting element. (For example, λ = 365 μm).

As a result, in the region corresponding to the light emitting region 9 irradiated with the ultraviolet light, the metal ions 13 in the gel film 4 are photoreduced, and a large number of metal fine particles 11 are formed. The light-emitting region 9 is formed by selectively reducing the metal ions 13 and depositing a large number of metal fine particles 11 on the gel film 4a formed in the above-described film forming process. By performing the reduction in response, the light emitting device 1 having a desired fine pattern can be formed.

According to the method using the photomask 15, photoreduction can be performed by irradiating ultraviolet light through the photomask 15. Therefore, even the light emitting region 9 having a complicated pattern can be formed in a relatively short time, which is suitable for mass production of the light emitting element 1.

(B) Spot Beam As shown in FIG. 6, a spot beam 21 is formed by using an optical system 17 for condensing ultraviolet rays (for example, ultraviolet laser) into irradiation light having a small diameter. Irradiation is performed while moving to an area corresponding to the light emitting area 9. As a result, in the region irradiated with the ultraviolet light, the metal ions 13 in the gel film are photoreduced, and the metal fine particles 11 are formed.

According to the method using the spot beam as described above, the spot beam can be irradiated locally while being moved only to the portion corresponding to the light emitting region 9, whereby the photoreduction can be performed locally. Therefore, it is possible to cope with various patterns of the light emitting region 9, and it is particularly suitable for high-mix low-volume production.

(C) Atomic Force Microscope In this method, as shown in FIG. 7, before the sol solution is dip-coated on the glass substrate 3,
The transparent electrode 23 is put on top. The transparent electrode 23 is, for example, an indium tin oxide (ITO) thin film, which is preferable because it has lower resistivity and less change with time than other types of transparent electrodes.

In the cantilever 25 of the atomic force microscope,
A metal coating 27 has been deposited in advance to provide conductivity. A bias power supply 29 is connected to the metal film 27 of the cantilever and the transparent electrode 23. Then, when the cantilever is moved to a position corresponding to the desired light emitting region 9 and a voltage is applied to the bias power supply 29, electrochemical local reduction of the metal ions 13 starts immediately below the cantilever 25. After the nucleus is formed, the metal ions 13 are supplied from the surrounding gel film 4a by diffusion and gradually increase in diameter to grow into metal particles 11.
According to the above-described means, only the extremely narrow area can be electrochemically reduced by moving the cantilever 25 of the atomic force microscope only to the area corresponding to the light emitting area 9 and applying a voltage. In addition, single metal fine particles can be formed, and an extremely fine pattern can be formed. As a result, utilization in single-electron devices such as single-electron transistors is also expected.

Further, since the size of the metal fine particles 11 formed on the gel film 4 can be controlled by making the voltage variable, it can be utilized for various optical functions.
For example, by forming metal fine particles 11 according to information, a CD-ROM, CD-R, CD-RW, DVD-
There is a possibility that a recording medium capable of writing information at an extremely high density as compared with a ROM or the like can be realized. In this case, the reading may be performed by using the principle of a proximity microscope (also called SNOM or NSOM) to read the presence or absence of the metal fine particles 11.

When the light emitting region 9 is formed on the sol film 4a to form the metal fine particle-doped thin film 4, a precursor sol solution (34) containing the organic fluorescent dye 19 is next prepared. The method for preparing the precursor sol solution containing the organic fluorescent dye 19 is as follows.
Is prepared in the same manner as above, except that an ethanol solution (1 × 10 ⁻³ M) of rhodamine B, which is an organic fluorescent dye 19, and Si (OC ₂ H ₅ ) ₄ and Ti (OC ₂ H ₅ ) Prepare by adding ₄ and HCl / H ₂ O as an acid catalyst. The organic fluorescent dye 19 is not limited to rhodamine, and other dyes such as coumarin may be used. Then, the precursor sol solution is hydrolyzed to generate a sol solution.

Next, the sol solution is dip-coated on the metal fine particle-doped thin film 4 described above, and the sol solution is gelled by thermal dehydration condensation (for example, heating at 150 ° C. for 1 minute). As shown in (5), a gel film (organic fluorescent dye-doped thin film 5) containing an organic fluorescent dye 19 is formed on a gel film (metal fine particle-doped thin film 4) containing metal fine particles 11 (35). In this embodiment, this gel film is referred to as an organic fluorescent dye-doped thin film 5.

As shown in FIG. 8, the fine metal-doped thin film 4 containing the metal ions 13 and the metal fine particles 11 grows upward when the metal ions 13 precipitate as the metal fine particles 11, as shown in FIG. In addition, the metal fine particles 11 protrude from the surface of the metal fine particle doped thin film 4 to form irregularities. However, as described above, by stacking different sol films in layers, that is, by forming the organic fluorescent dye-doped thin film 5 containing the organic fluorescent dye 19 on the metal fine particle-doped thin film 4 containing the metal fine particles 11, The fine particles 11 do not project on the surface of the film.

Here, the light emitting device 1 according to the present invention will be described.

As shown in FIG. 9, the light-emitting device 1 produced by the above-described manufacturing method has two layers of gel films, an organic fluorescent dye-doped thin film 5 and a metal fine particle-doped thin film 4, on the upper surface of a glass substrate 3. Do it. The organic fluorescent dye-doped thin film 5 and the metal fine particle-doped thin film 4 are formed of silica (SiO ₂ ) / titania (TiO ₂ ) and have a thickness of, for example, about 0.1 to 1 μm. Although the light emitting region 9 is formed in the metal fine particle doped thin film 4, not only the light emitting region 9 but also the non-light emitting region 7 is formed by using the selective reduction method shown in the above (A), (B) and (C). The light emitting region 9 may be formed. In the light emitting region 9, a large number of metal fine particles 11 having a diameter of about several nm to 20 nm are formed by being deposited almost uniformly spatially, and in the non-light emitting region 7, a large number of metal ions 1 are formed.
3 are arranged substantially evenly. The metal fine particles 11 arranged in the light emitting region 9 are deposited by reducing the metal ions 13. The organic fluorescent dye-doped thin film 5 contains an organic fluorescent dye 19, which also has metal fine particles 11 and metal ions 13.
Are arranged in a dispersed manner as in

In this embodiment, the above-mentioned glass substrate 3 corresponds to the substrate in the present invention, and the gel films above and below the organic fluorescent dye-doped thin film 5 and the metal fine particle-doped thin film 4 correspond to the films. In this embodiment, gold (Au) is used as the metal and rhodamine B (rhodamine B) is used as the organic fluorescent dye.

The use of “gold” as the metal of the metal fine particles 11 and the metal ions 13 as in the above embodiment is a metal in which the gold fine particles can be deposited relatively stably. It is preferable because the light emission can be performed stably. In addition, silver, platinum, etc. other than gold can be used as the metal.

Further, since rhodamine B is employed as the organic fluorescent dye 19, fluorescent light can be generated in the light emitting region 9 and red-based coloring can be performed. In addition, the organic fluorescent dye 19 may be any as long as its luminous body is in a longer wavelength region than the absorber of the metal fine particles 11. For example, when the metal fine particles 11 are gold fine particles, rhodamine 6G (rhodamine 6G) is used. ), Or the like, or when the metal fine particles 11 are silver, coumarin may be used to produce a blue color.

Furthermore, it has been reported that due to the effect of titania (TiO ₂ ), the fine gold particles generated in the film by reduction are not in the form of a series of needle-like crystals or square plate-like crystals, but are easy to form spherical ones. I have. Therefore, the metal fine particle doped thin film 4
Also, since the gel film of the organic fluorescent dye-doped thin film 5 is a silica / titania thin film, the spherical metal fine particles 11 are present in the thin film, the light emitting region 9 can be formed neatly, and turbidity and unevenness of light emission hardly occur. Has become. The gel film is not limited to the silica / titania thin film described above, but may be a silica thin film or a titania thin film.

Next, in order to show the properties of the light emitting device 1 according to the present invention, the light emitting device 1 using gold ions as the metal fine particles 11 and rhodamine B as the organic fluorescent dye 19 will be described as an example. .

On the upper surface of the glass substrate 3, a light emitting element 1 having an upper and lower two-layered gel film of an organic fluorescent dye-doped thin film 5 and a metal fine particle-doped thin film 4 is applied to an excitation light 30 (for example, λ =
547 nm), and observed with a fluorescence microscope, for example, as shown in FIG. Laser oscillation can also be achieved by injecting and exciting a high current using the conductivity of metal fine particles.

When light is excited as described above, the light-emitting region 9 is irradiated with the excitation light 30 so that the organic fluorescent dye 19, rhodamine B, is emitted.
The fluorescent red color appears to appear. In the drawing, the light-emitting region 9 that emerges in red is represented by white, and the non-light-emitting region 7 that does not emit light and appears to sink in black is represented by hatching.

The non-light emitting region 7 of the light emitting element 1 contains an organic fluorescent dye 19 and metal ions 13, and the light emitting region 9 contains the organic fluorescent dye 19 and metal fine particles 11 precipitated from the metal ions 13. Therefore, in the non-light emitting region 7, light emission by the organic fluorescent dye 19 is suppressed by the metal ions 13. On the other hand, the organic fluorescent dye 19
There is nothing that suppresses light emission due to light emission, and light emission can be generated as it is. Therefore, by selectively reducing the metal ions 13 to precipitate the metal fine particles 11, a light emitting device having a fine pattern of the light emitting region 9 can be obtained.

Further, the metal fine particles 11 and the organic fluorescent dye 1
Light-emitting element 1 in which a film in which N.
/ Nd laser is used for photoexcitation to obtain FIG.
It was confirmed that the laser oscillation as shown in FIG. FIG. 14 shows the oscillation intensity (PL intensity) of the light-emitting element 1 according to the present invention, where the horizontal axis represents the wavelength (wavelength).
It is the graph which showed y).

The dependence of the oscillation intensity of the laser oscillation on the excitation energy was compared with that of the light emitting element 2 in which the thin film 6 doped only with the organic fluorescent dye was provided on the glass substrate 3 as shown in FIG. FIG. 15 shows the oscillation intensity (PL int
is a graph showing excitation energy (Pulse energy) on the vertical axis. In the figure, reference numeral 41 denotes a light emitting element 1 in which a film in which a metal fine particle 11 and an organic fluorescent dye 19 are individually doped is laminated.
In the figure, reference numeral 42 indicates the result of photoexcitation of the light emitting element 2 doped only with the organic fluorescent dye 19 using a YAG / Nd laser. FIG. 15 shows that the light-emitting element 1 according to the present invention can obtain a strong thin-film laser action with low excitation energy. The above-described measurement uses gold fine particles as the metal fine particles 11 and rhodamine B as the organic fluorescent dye 19 as an example.

From the above results, when the light emitting element 1 is optically excited by the excitation light 30, the surface plasmon resonance absorption band of the metal fine particles 11 and the absorption band of the organic fluorescent dye 19 are cooperatively excited, as shown in FIG. Then, a local electromagnetic field 50 is generated due to the plasmon excitation of the metal fine particles, and the stimulated emission 19b of the organic fluorescent dye 19 is amplified. That is, the laser oscillation of the organic fluorescent dye 19 of the organic fluorescent dye-doped thin film 5 is amplified by the action of the metal fine particles 11.

Therefore, compared to the light emitting device 2 doped only with the organic fluorescent dye 19, the light emitting device 1 in which the metal fine particles 11 according to the present invention and the film doped only with the organic fluorescent dye 19 are laminated has a lower excitation energy threshold. Oscillates,
The thin-film laser action based on the emission of the organic fluorescent dye is significantly enhanced. In other words, the light emitting device 1 according to the present invention can be excited at a low energy level, and can stabilize the organic material.

In the graph shown in FIG. 16, the vertical axis represents the absorption spectrum (Absorbance) and the fluorescence spectrum (Fluorescenc).
e) The wavelength (Wavelength) is plotted on the horizontal axis, and the surface plasmon resonance absorption 43 of the fine gold particles and the absorption 44 of rhodamine are measured.
And the fluorescence 45 of rhodamine. In this example, the excitation light 30 used for the measurement had a wavelength indicated by an arrow 46 in the graph of FIG. In order to express the cooperative amplification phenomenon of the metal fine particles 11 and the organic fluorescent dye 19, the organic fluorescent dye 1
Since it is a condition that the emission of No. 9 is not suppressed by the surface plasmon resonance absorption of the metal fine particles 11, it is necessary to design the material so that the surface plasmon band of the metal fine particles 11 overlaps the absorption band of the organic fluorescent dye 19. .

Under the above conditions, the metal fine particles 11
By changing the material type and size of the organic fluorescent dye 19 and the size thereof, light emission having a desired color and intensity can be promoted. Therefore, in addition to changing the material type, for example, the size of the metal fine particles can be controlled by a reduction method, and in the above-described selective reduction methods (A) and (B), the ultraviolet light irradiation time is reduced. With this, it is possible to control the size of the metal fine particles. The refractive index of the thin film can be controlled by the silicon / titanium (Si / Ti) ratio in the thin film, and the film thickness can be controlled by the dipping speed of the gel solution in the process of forming the thin film. In this way, it is possible to emit various lights under various conditions.

[0050]

The present invention is configured as described above.
The following effects are obtained.

That is, in a light emitting device having a layered film formed on a substrate, a film containing fine metal particles is formed on the substrate, and a film containing an organic fluorescent dye is formed thereon. Therefore, utilizing the resonance excitation of metal fine particles,
Oscillation of the organic fluorescent dye-doped thin film can be enhanced cooperatively, and laser oscillation can be generated at a low excitation energy threshold, so that the stability of the organic molecular material can be improved. Further, since an organic molecular material is used, the emission wavelength can be easily selected, and development to an organic laser diode is expected.

Since the metal of the fine metal particles is gold (Au), the fine metal particles can be deposited relatively stably, so that the light emission in the light emitting region can be stably performed. It can be done.

According to the third aspect of the present invention, since the organic fluorescent dye is rhodamine B, it is possible to generate fluorescent light in the light emitting region and to generate reddish color.

According to the fourth aspect, since the organic fluorescent dye is coumarin, it is possible to generate fluorescent light in the light emitting region and to perform blue coloration.

According to a fifth aspect of the present invention, at least one of the films is a silica (SiO ₂ ) / titania (TiO ₂ ) thin film, so that the growth of metal particles is promoted. Easy to form. Therefore, the light emitting region can be formed neatly, and unevenness in light emission hardly occurs. In addition, it is an inexpensive material, which facilitates mass production.

As described in claim 6, when the light emitting element is used as an optical device material, the light emitting element can excite an organic fluorescent dye at a low energy level, and since it is an organic molecular material, it is easy to select an emission wavelength. High speed, high density and large capacity of information and communication are expected.

When the light emitting element is used as a laser material as described in claim 7, laser oscillation can be generated with a low excitation energy threshold, so that the stability of the organic molecular material can be improved. Since the material is suitable for improving the stability of organic molecules under high current injection and lowering the excitation energy threshold, which are issues for realizing a thin film laser, a dramatic improvement in laser characteristics is expected.

In a light-emitting device having a layered film formed on a substrate, (1) a film forming step of forming a film containing metal ions on the substrate, (2) a metal ion in the thin film Is selectively reduced to form metal fine particles to form a light emitting region, and (3) a film forming process of forming a film containing an organic fluorescent dye on a substrate is sequentially performed. By selectively reducing metal ions with respect to the formed film, a light emitting region can be limited, and a light emitting element having a fine pattern can be easily formed. In addition, since the manufacturing process is simple and does not require sophisticated equipment, it can be produced with inexpensive equipment, which facilitates mass production.

According to a ninth aspect of the present invention, at least one of the film forming steps includes a step of forming silica (Si) containing an organic luminescent dye.
O ₂₎ / titania (TiO ₂₎ precursor sol solution, or silica containing metal ions (SiO ₂₎ / titania (TiO ₂₎ with a precursor sol solution, sol - since the deposited gel method,
Since the film formation process can be performed at a low temperature, it can be manufactured relatively easily. In addition, metal ions and organic fluorescent dyes can be arranged almost evenly in the film, and metal fine particles can be arranged almost evenly.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an overall flow of a method for manufacturing a light emitting device according to the present invention.

FIG. 2 is a diagram showing a flow of a film forming process.

FIG. 3 is a schematic sectional view in which a gel film is dip-coated on a substrate.

FIG. 4 is a schematic cross-sectional view in which a metal fine particle-doped thin film is similarly formed on a substrate.

FIG. 5 is an explanatory diagram of a selective reduction process using a photomask.

FIG. 6 is an explanatory diagram of a selective reduction process using a spot beam.

FIG. 7 is an explanatory diagram of a selective reduction process using an atomic force microscope.

FIG. 8 is a view showing a light emitting device after a selective reduction process.

FIG. 9 is a cross-sectional view schematically showing one example of a vertical cross section of the light emitting device according to the present invention.

FIG. 10 is a schematic diagram of a fluorescence image of the light-emitting element observed with a fluorescence microscope.

FIG. 11 is a cross-sectional view schematically illustrating an example of a vertical cross section of a light emitting device doped only with an organic light emitting device.

FIG. 12 is a cross-sectional view schematically showing one example of a vertical cross-section when a light-emitting element according to the present invention is photoexcited.

FIG. 13 is a view showing a mechanism of an action of enhancing the laser oscillation of the organic fluorescent dye.

FIG. 14 is a diagram showing the oscillation intensity of the light emitting device according to the present invention.

FIG. 15 is a diagram showing the relationship between the oscillation intensity and the excitation energy of the light emitting device according to the present invention and a light emitting device doped only with an organic fluorescent dye.

FIG. 16 shows the absorption of rhodamine and gold and the fluorescence of rhodamine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light emitting element 3 Substrate 4 Metal fine particle doped thin film 5 Organic fluorescent dye doped thin film 7 Non-light emitting area 9 Light emitting area 11 Metal fine particle 13 Metal ion 19 Organic fluorescent dye

Claims (9)

[Claims] 1. A light-emitting element having a layered film formed on a substrate, wherein a film containing fine metal particles is formed on the substrate, and a film containing an organic fluorescent dye is formed thereon and laminated. element. 2. The light emitting device according to claim 1, wherein the metal of the metal fine particles is gold (Au). 3. The method according to claim 2, wherein the organic fluorescent dye is rhodamine B (rhod
The light-emitting device according to claim 1, wherein the light-emitting device is amine B). 4. The method according to claim 1, wherein the organic fluorescent dye is coumarin.
The light emitting device according to claim 1 or 2, wherein n) is satisfied. 5. The film according to claim 1, wherein at least one of the films is made of silica (Si
O ₂₎ / titania (TiO ₂₎ light-emitting device according to any one of claims 1 to 4, characterized in that a thin film. 6. The light emitting device according to claim 1, wherein the light emitting device is used as an optical device material. 7. The light emitting device according to claim 1, wherein the light emitting device is used as a laser material. 8. In a light emitting device having a layered film formed on a substrate, (1) a film forming step of forming a film containing metal ions on the substrate, and (2) selective reduction of metal ions in the thin film. And (3) forming a film containing an organic fluorescent dye on a substrate by sequentially performing a selective reduction process of forming a light emitting region by forming metal fine particles. Production method. 9. The method for manufacturing a light emitting device, wherein at least one of the film forming processes includes a silica (SiO ₂ ) / titania (TiO ₂ ) precursor sol solution containing an organic luminescent dye.
Alternatively, using silica (SiO ₂₎ / titania (TiO ₂₎ precursor sol solution containing metal ions, sol - manufacturing process of a light emitting device according to claim 8, characterized in that the film-forming gel method.