JPH02234301A - Luminous material - Google Patents

Abstract

PURPOSE:To increase luminous intensity or enable the addition of luminous characteristics by impregnating a luminous material with fine particles of IV group elements containing at least a halogen element. CONSTITUTION:A luminous material emitting light when applied with excitation energy is impregnated with IV group elements containing at least a halogen element. In this case, it is preferable from a viewpoint of easy handling to use a luminous material having an aggregate of fine particles formed in such a way that the fine particles are dispersed in a fine particle film or binder deposited in layer on a substrate. Also, the size of the fine particle may be approximately equal to or less than the wave-length of emitted light. In the case of visible rays, the size is approximately equal to or less than 1mum, or preferably equal to or less than 0.1mum, or more preferably equal to or less than 500Angstrom . According to the aforesaid construction, it is possible to make luminous the material that does not emit light at normal temperature or drastically increase luminous intensity. In addition, the material is almost free from a secular change and it is possible for the material to be luminous stably at all times.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electric field. Electric wire, X-ray. The present invention relates to a light-emitting member that emits light such as fluorescence or phosphorescence by absorbing excitation energy such as ultraviolet light, visible light, or infrared light.

[Conventional technology]

Conventionally, various types of light-emitting members that emit fluorescence or phosphorescence have been known. For example, Ga, which is a direct transition type semiconductor,
■Crystals of Group 1V compounds such as As and InP, ZnS,
When crystals of group ■~■ compounds such as ZnSe are irradiated with light of energy greater than the band gap of these materials, they absorb it and emit light with lower energy than the irradiated light, that is, the excitation light, and emit light. do. Furthermore, even a so-called indirect transition type material, such as SiC, emits considerably strong light if a recombination center is created within the band gap. Further, in highly ionic crystals, fluorescence occurs due to impurities. For example, in MCI: Tl'', Tl◆ ions are excited by short wavelength excitation light, and 196n [and 2
A fluorescence spectrum peak appears at 49 nm. Such light emission is caused not only by electromagnetic waves but also by electron beams. For example, Y,02 is a phosphor used in cathode ray tubes.
In S, Eu″4 is added as an activator impurity,
Red light emission is caused by electron beam irradiation. Many examples of this are known, such as blue fluorescence due to 8g8 to ZnS and orange fluorescence due to Mn addition to ZnF2. Also, for example, Applied Physics
Another conventionally known method is to apply an electric field to a light-emitting member by attaching an electrode to the light-emitting member to emit light, as shown in ``S Letters 13, 210 (1968).

For example, when microcrystalline grains such as ZnS doped with Mn or ZnS doped with Cu and CI are dispersed in a binder as a light emitting member and an alternating current electric field is applied to it, light is emitted by so-called electroluminescence (EL). Can be seen. These are used for displays, etc.

Injection light emission using a p-ro junction of a direct transition type semiconductor such as an m-V group compound is also a well-known technology at present. Furthermore, a semiconductor laser is an improved version of such a so-called LED and has made it possible to generate laser oscillation. For example, S. M. P by Sze
dynamics of Se+siliconductor
Devices Chapter 12 (John Ililey &
Sons. (1981) and other standard reference books, and there are many products on the market.

By applying excitation energy in various ways like this,
Light-emitting members that emit light such as ultraviolet light, visible light, or infrared light are well known. Generally, these luminescent characteristics can be checked by first examining the presence or absence of photoluminescence, its intensity, and its emission wavelength distribution.

[Problem that the invention is trying to solve]

However, on the other hand, there were also many that had low luminescence intensity or did not emit light to the extent that their luminous properties could be used for practical purposes. In addition, even if a material has a fairly high internal quantum efficiency for light emission, its high refractive index means that the critical angle at which the emitted light can exit is small, so it cannot escape from the inside and is unable to escape before exiting. In many cases, the light is attenuated due to repeated multiple reflections. Furthermore, since the wavelength of the emitted light is often easily absorbed, multiple internal reflections are disadvantageous in terms of the utilization of the emitted light, and have become a major problem. In order to solve these problems, it is necessary not only to improve the physical properties of the light emitting material, but also to devise ways to efficiently extract the emitted light to the outside as described above. The phenomena became quite complex, and it was difficult to solve them comprehensively.

An object of the present invention is to provide a novel light-emitting member in which the substantial light-emitting intensity of the above-mentioned weak light-emitting materials is increased or new light-emitting characteristics are added.

(Means for Solving the Problems) The present invention provides a light-emitting member that emits light upon application of excitation energy, characterized in that the light-emitting portion contains fine particles of a group III element containing at least a halogen element. It is a member.

In particular, from the viewpoint of ease of handling, it is desirable to use a light-emitting member in the form of a fine particle film in which aggregates of fine particles are deposited in a layer on a substrate or a binder-dispersed film in which fine particles are dispersed in a binder. Efficacy is not limited to such particulate or binder dispersed films.

The fine particles used in the present invention may have a size comparable to or smaller than the emission wavelength. In the case of visible light emission, the number is approximately 1μ1 or less, preferably 0.1μ or less, and more preferably 500 or less.

Although the shape of the above-mentioned fine particles is not particularly limited,
It is more effective if the particles are relatively spherical and do not contain too large particles. The lower limit of the size is unknown, but according to observation results using a transmission electron microscope (TEM) and a field emission scanning electron microscope, the effect is recognized even with ultrafine particles with an average particle size of several 100 people. .

In practical use, in order to handle the fine particles of the present invention as described above, it is sufficient to place them on some kind of substrate and fix them. In this case, the individual fine particles do not necessarily have to be in contact with each other and may be isolated on the substrate, but in general, in order to increase the overall luminescence intensity, it is necessary to form aggregations of fine particles, such as aggregates or deposited films. etc. is preferable.

In the fine particles according to the present invention, a material containing a halogen and surprisingly increasing the emission intensity is a group II material such as silicon, but Ge, C, and a mixed material thereof are also effective.

The raw material gas used in the light emitting member of the present invention is 5i
In addition to F4 and SiCl4, examples of silane derivatives used in Si film formation, such as Si2F. , St2CI
, etc. can also be used. In addition, other group II gases,
For example, it is possible to use CF4, CF3DH, 02F6 and other hydrocarbon gases, as well as Ge type gases.

There are also two types of gases, such as %Si-based gas and C-based gas, and Si-based gas and Ge-based gas. It is also possible to use a mixture of three types of gases. Furthermore, it is also possible to use these gases to generate active gases that do not exist in nature and dilute them to generate fine particles. For example, ＾1AB,→2＾B2 ＾: Group ■ element B: Halogen element can be reacted to generate active 8n2 gas. In addition, halogen gas is introduced into the carrier gas, and
After the fine particles are prepared, halogen can be introduced by heat treatment in a halogen gas atmosphere or the like.

Furthermore, the amount of halogen to be included is preferably fea
ts% (M.% as number of children) or more, more preferably 2 oat meal% or more.

As a method for forming the fine particles used in the light-emitting member of the present invention, various methods generally used for producing ultrafine particles can be used. For example, Japanese Journal of
Ap9liad Physics, (2), 702
, (1963) and Che.
sitry Letters, 267, (1986
Examples include the thermophoretic CVD method as seen in ), or a method of synthesis in a liquid. Such methods for producing super-featured particles are now well known in the field of super-featured particles, and are not limited to the individual production methods described above. For information on these various methods, see, for example, edited by the Chemical Society of Japan. Chemistry review No. 48 r Super Particles J (1985) and other publications.

Of course, a method other than the above-mentioned method may be used to make the fine particles contain at least halogen.

In any case, it was found that the degree of halogen content affects the luminescence intensity of the light-emitting member.

It is not necessarily clear why the finer particles of the material and the inclusion of a halogen element according to the present invention cause an increase in luminescence intensity.

However, since the surface area has significantly increased due to the material becoming finer particles, it is thought that the surface may become active or some physical property change may occur.

In addition to this, it is also conceivable that the light extraction efficiency is increased due to a decrease in reflectance due to the formation of fine particles when light is emitted from the center of the light emitting member to the outside. Furthermore, when the light-emitting member is a particulate film laminated on a substrate, the light emitted from a deep part of the surface of the film is not scattered much because the size of the particulates is much smaller than the wavelength of the light. It is also conceivable that the luminescence intensity appears to increase due to the fact that it reaches .

Furthermore, it is thought that containing at least a halogen in the fine particles reduces dangling bonds, reduces non-luminous centers, and increases luminescence intensity.

Furthermore, the introduction of halogen makes it possible to obtain a material that is stable against light irradiation and heat.

Further, the fine particle film in which the fine particles are deposited on the substrate in the light emitting member of the present invention may be provided with a protective layer on its surface. This protection layer is effective for increasing the mechanical strength of the fine particle film and for preventing deterioration and other changes in the light emitting layer due to alteration. Boristyrene. Carbonate and other organic polymers, inorganic glasses such as quartz and low-melting glass, or plasma polymerized films such as SiN, a-C, and others can be used. For organic polymers, it is convenient to use methods such as solvent coating. In addition, when forming the fine particles in the form of a binder-dispersed film, there is a method in which a synthetic resin or the like is coated on the surface of the fine particles using a heating vapor deposition method and then deposited, or a method in which the fine particles are kneaded in a binder and stretched into a thin film. etc.

(Examples) The present invention will be specifically described below based on Examples.Example 1 Si:F:H fine particles were deposited on a silicon wafer substrate 7 using the apparatus shown in FIG.

To create the light emitting member, first set the silicon wafer substrate on the substrate holder 6, and then use the exhaust system 11 to open the downstream chamber 4 by 2 x
The pressure was reduced to 10-'Torr. ．． Next is Ar and 11.

SiF4 diluted to 3% with a mixed gas (mixing ratio 1:9) of
Gas is introduced into the air conditioning resonator 5 from the gas introduction pipe lO at a flow rate of 100.
5c (:M).Then, the pressure inside the cavity resonator S was 4
X 10-'Torr, SiF4 from nozzle 1
Gas containing gas was blown out to the downstream chamber 4. At this time, the pressure inside the downstream chamber 4 was 4.5 x 10-3 Torr. Next, microwaves are sent from a microwave generator (not shown) into the cavity resonator 5 through the waveguide 9 and the quartz window 8.
Discharge plasma was generated within the cavity co-container 5. The power of the microwave was 1501#. Then, fine particles are formed in the plasma and flow into the nozzle 1 along with the remaining gas components.
The particles were blown out into the downstream chamber 4 and collided with the substrate 7 in the downstream chamber 4 as a particle beam, thereby fixing the particles on the substrate 7.

The thickness of the layer of fine particles deposited on the substrate 7 was 3.5 μm after 5 minutes of discharge. The color of the fine particle deposits was yellowish-brown and shiny film-like deposits.

Example 2? Using the same method as in Example 1, the raw material gas was converted from StF4 to S.
A deposited film was obtained in exactly the same manner as in Example 1, except that iCl2 was used, the diluting gas was changed to 100% I12, and the microwave power input was changed to 80VI.

Example 3 In the same manner as in Example 1, raw material gas was converted to SiF. From Ge
F4/Sin4=174 and the diluting gas }l
A deposited film was obtained in exactly the same manner except that the ratio was changed from , /Ar=9/1 to ]1■100%.

Example 4 SiF. By passing through it, a reaction of Si+SiF4→2.SjF2 is caused, and active SiF and gas are generated. This active SiF
2 gas is used as the raw material gas, and the gas to be diluted is II, /A
A deposited film was obtained in exactly the same manner as in Example 1 except that r=9/1 was changed to lh 100%.

Comparative Example 1 A deposited film was obtained by the usual glow discharge decomposition method using the same raw materials and diluent gas as in Example 1.

The membrane obtained as described above was evaluated using the following ladder.

(2) Shape of deposited film The shape of the film surface was observed using FE-SEM (manufactured by Hitachi).

■Halogen content Shimadzu EPM^/Model: EMX-SM (Electro
The halogen content in the film was measured using a probe micro analysis.

(2) Photoluminescence Ar ion laser (488 nm) was irradiated at room temperature, and photoluminescence was observed using a photomultiplier tube.

A summary of the evaluation results is shown in Table-1.

Table-! *2 >> Relative value when Example 1 is taken as 100 Further, the spectrum of Example 1 is shown in FIG. 2 as an example of the photoluminescence spectrum.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to make materials that normally do not emit light at room temperature emit light, or to dramatically increase the luminous intensity of materials that normally emit light.

Furthermore, the light-emitting member of the present invention hardly changes over time,
It is capable of constantly emitting stable light.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an apparatus used to produce the light emitting member of the present invention, and FIG. 2 is a diagram showing a fluorescence spectrum caused by excitation light of a 488 nm ion laser. 1...Reduction/expansion nozzle 2...Nozzle throat 2a, 2b...Nozzle opening 3...Magnet 4...Downstream chamber 5. ...Cavity communicator 6 ...Base holder 7 ...Base 8 ...Microwave introduction window 9 ...Microwave waveguide lO ... Gas inlet ■ ... Exhaust system Patent applicant Canon Inc.

Claims (1)

[Claims] 1. A light-emitting member that emits light upon application of excitation energy, characterized in that the light-emitting member contains fine particles of a group IV element containing at least a halogen element.