JP2004307808A - Gadolinium oxide-vanadium oxide multicomponent oxide white luminous fluorescent material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gadolinium oxide-vanadium oxide multicomponent oxide white luminous fluorescent material which has high brightness, high color purity and high stability and to provide a white luminous thin film electroluminescent element which uses a thin film of the fluorescent material as a luminescent layer. <P>SOLUTION: The gadolinium oxide-vanadium oxide multicomponent oxide white luminous fluorescent material comprises a gadolinium oxide-vanadium oxide multicomponent oxide as a base material, whose main component is gadolinium(Gd) and vanadium(V), and contains as luminescence center materials thulium(Tm), erbium(Er) and europium(Eu) to gadolinium(Gd) each 0.9-2.0 atom%, 0.2-1.0 atom% and 0.05-0.4 atom%, preferably each 1.0-1.5 atom%, 0.5-0.9 atom% and 0.1-0.3 atom%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

DETAILED DESCRIPTION OF THE INVENTION

Industrial applications

The present invention relates to a gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor and a thin film electroluminescent device using a thin film of the phosphor for a light emitting layer.

As a conventional white light-emitting phosphor thin film for an electroluminescence element (hereinafter referred to as an EL element), a plurality of metal elements such as cerium (Ce), potassium (K), and europium (Eu) are simultaneously applied to strontium sulfide (SrS) or the like. Sulfide phosphor thin films added as emission center materials and charge compensation materials have been developed.

Problems to be solved by the invention

However, the above-mentioned sulfide-based phosphor thin film has not been able to realize sufficient characteristics in both luminance and white purity. In addition, all of the above-mentioned sulfide phosphor thin films are chemically unstable, and particularly extremely unstable with respect to moisture. Therefore, a special sealing for completely removing moisture is required at the time of manufacturing a thin film EL device. Stop processing must be performed, which has a fatal drawback that it increases the manufacturing cost of the device.

In view of such circumstances, the present invention provides a novel gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor using a chemically extremely stable oxide as a base material, and a thin film of the phosphor as a light-emitting layer. It is an object to provide a thin-film electroluminescence element.

Means for solving the problem

According to a first aspect of the present invention for solving the above-mentioned problem, in a Gd-VO-based oxide containing gadolinium (Gd) and vanadium (V) as main components, a metal element added as a luminescent center material is thulium. (Tm), erbium (Er) and europium (Eu), respectively, from 0.9 to 2.0 atomic%, 0.2 to 1.0 atomic% and 0.05 to 0 atomic% with respect to gadolinium (Gd). Gadolinium oxide-vanadium oxide, characterized by containing 0.4 at%, preferably 1.0 to 1.5 at%, 0.5 to 0.9 at% and 0.1 to 0.3 at%, respectively. Multi-component oxide white light emitting phosphor.

According to a second aspect of the present invention, there is provided gadolinium oxide-vanadium oxide multi-component oxide white light-emitting fluorescence, which contains 40 to 60 atomic%, preferably 45 to 55 atomic% of vanadium (V) in a base material. In the body.

In a third aspect of the present invention, the base material is a composite oxide composed of gadolinium oxide (Gd ₂ O ₃ ) and vanadium oxide (V ₂ O ₅ ), wherein gadolinium oxide-vanadium oxide multi-component oxidation is performed. In the white light-emitting phosphor thin film.

A fourth aspect of the present invention resides in a gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor, wherein the base material is mainly composed of GdVO ₄ which is a ternary compound.

A fifth aspect of the present invention is characterized in that the gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor according to any one of the first to fourth aspects is thinned by a known method and used as a light emitting layer. White light-emitting thin film electroluminescent element.

The present invention relates to a Gd-VO-based oxide which is a new base material system, which has been invented in the research on multi-component oxide phosphors conducted by the applicants, and uses thulium (Tm) as a luminescent center material. , Erbium (Er) and europium (Eu) can be used simultaneously as a white thin-film phosphor.

That is, the base material is an oxide containing gadolinium (Gd) and vanadium (V), and Tm, Er, and Eu are used as the activator.

Thulium (Tm), erbium (Er), and europium (Eu), which are luminescent center materials serving as luminescent centers, are 0.9 to 2.0 atomic% and 0.2 to 1.0 atomic% with respect to gadolinium (Gd), respectively. At% and 0.05 to 0.4 at%, preferably 1.0 to 1.5 at%, 0.5 to 0.9 at% and 0.1 to 0.3 at%, respectively. do it.

The Gd-V-O-based oxide as a base material of the present invention, gadolinium oxide - can be exemplified GdVO ₄ or the like as a composite oxide or 3 Motoka such oxide vanadium oxide.

The vanadium (V) content in the Gd-VO-based oxide of the present invention is 40 to 60 atomic%, preferably 45 to 55 atomic% with respect to gadolinium (Gd).

The gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor of the present invention is achieved by adding a luminescent center to a host material and optimizing the phosphor production conditions such as the chemical composition of the host material and firing conditions. it can. The phosphor can be used as a light emitting layer for an EL element by processing it into a desired shape.

Examples of the structure of the light emitting layer for a thin film EL element include a known thin film insulating structure, a thin film double insulating structure, a single insulating structure using a ceramic type insulating layer, and a double insulating structure of a thin film and ceramics. It is not limited to these.

FIG. 1 shows an example of a typical thin film EL element having a thin film piece insulating structure. As shown in FIG. 1, a gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor thin film according to the present invention is formed on an insulating substrate such as a BaTiO ₃ substrate. A transparent conductive film of ZnO: Al or the like is provided on the phosphor thin film by sputtering or the like, and a back electrode made of an evaporated Al film or the like is provided on the opposite side of the insulating substrate. Is configured.

In such a thin film electroluminescent element, when an AC voltage of 50 to 600 V is applied between the transparent conductive film and the back electrode, the phosphor thin film emits light.

The thin film of the white light-emitting oxide phosphor according to the present invention is formed by using a known thin film deposition technique such as a sputtering method, a chemical vapor deposition (CVD) method, an electron beam evaporation method, an atomic layer epitaxy method, or a laser ablation method. After film formation, heat treatment in air, in an atmosphere containing inert gas or sulfur, in vacuum, in a non-oxidizing gas, or in a non-oxidizing gas atmosphere containing a partially oxidizing gas or a partially reducing gas and sulfur By applying, a sufficient function as a light emitting layer for a thin film electroluminescence element can be provided. The preferred temperature range for the heat treatment is 850-1100 ° C, preferably 950-1050 ° C.

In addition, taking advantage of the chemical stability of the oxide phosphor of the present invention, a known chemical film forming method using an aqueous solution, for example, a film forming method using a solution coating method or a sol-gel method, followed by heat treatment Is also effective.

The thickness of the oxide thin film phosphor formed using the above-described thin film deposition technique is 0.1 to 10 μm, and more preferably 0.5 to 3 μm. In the above-described film forming method, by setting appropriate film forming conditions, it is possible to control the characteristics of the thin film EL element and realize white light emission.

As the transparent electrode, a transparent conductive film such as ZnO: Al, SnO ₂ : F, SnO ₂ : Sb, and indium tin oxide (ITO) can be used. As an example of the insulating layer, BaTiO ₃ can be given, but it is sufficient that the relative dielectric constant is 100 or more, and BaTiO ₃ is not necessarily required as long as it can withstand a heat treatment at about 900 ° C. There is no particular limitation on the element structure, and various types of ceramics such as quartz and alumina having a heat resistance of 900 ° C. or more and various single crystals such as sapphire are used as a base material, and a conventional double insulating structure is employed. That is no problem.

The above-mentioned base material is easily crystallized by performing a heat treatment at about 900 to 1000 ° C., so that a highly crystalline phosphor can be manufactured. As a result, in an EL element using this as a light-emitting layer, the generation efficiency of hot electrons when a high electric field is applied is increased, so that the excitation efficiency of the emission center is also greatly improved, and a high light emission luminance is obtained.

Hereinafter, embodiments of the present invention will be described with reference to examples, but are merely examples, and the present invention is not limited thereto.
(Example 1)

As a luminescent center material, thulium dioxide (Tm ₂ O ₃ ) powder, europium dioxide (Eu ₂ O ₃ ) powder, and erbium dioxide (Er ₂ ) as a luminescent center material in a powder in which vanadium (V) is mixed with gadolinium (Gd) at 50 atomic%. O ₃ ) powder was sufficiently mixed with Gd to contain 1.0 atomic%, 0.2 atomic%, and 0.7 atomic%, respectively, and then at 1000 ° C. in an argon (Ar) gas atmosphere. By calcination for a period of time, a gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor powder was produced, which was co-added with Tm, Eu, and Er. A sputtering target is prepared using the phosphor powder, and a sintered barium titanate (BaTiO ₃ ) ceramic substrate / insulator layer is provided with a gas pressure of 6 Pa, a sputtering power of 100 W, a substrate temperature of 275 in argon (Ar) gas. A Tm, Eu, and Er co-doped gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor thin film light-emitting layer was formed under the conditions of a temperature of 390C to 390C and a distance between the substrate and the target of 25 mm. Thereafter, an annealing treatment was performed at 1020 ° C. for one hour in the air. After the heat treatment, the phosphor thin film realized high-efficiency white light emission in both photoluminescence (PL) and cathodoluminescence (CL).

Then, an aluminum-added zinc oxide (ZnO: Al) transparent electrode was formed on the light-emitting layer thin film, and a metal Al electrode was formed on the back surface, to produce an EL element. When a 1-kHz sine-wave AC voltage was applied to the EL element, white EL light emission of color purity enough to withstand practical use was realized as shown in FIG. In addition, as shown in FIG. 3, high-brightness white EL light emission that can withstand practical use was realized. Thereby, the Tm, Eu, and Er co-added gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor thin film sufficiently functioned as a light emitting layer thin film for an EL element.
(Example 2)

Thulium dioxide (Tm ₂ O ₃ ) powder, europium dioxide (Eu ₂ O ₃ ) powder, and erbium dioxide (Er ₂ O) as emission center materials in a powder obtained by mixing vanadium (V) with gadolinium (Gd) at 50 atomic%. ₃ ) The powder is sufficiently mixed with Gd so as to contain 1.0, 0.1 and 0.7 atomic%, respectively, and then fired at 1000 ° C. for 1 hour in an argon (Ar) gas atmosphere. , Tm, Eu and Er co-added gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor powder was prepared. A sputtering target was prepared using the fired phosphor powder, and an antimony-added tin oxide (SnO ₂ : Sb) transparent electrode was grown on a single crystal sapphire substrate, and an aluminum oxide (Al ₂ O ₃ ) insulating layer was grown thereon. Tm, Eu, Er co-added gadolinium oxide-vanadium oxide phosphor under argon (Ar) gas, gas pressure of 6 Pa, sputter input power of 100 W, substrate temperature of 250 to 800 ° C., and substrate-target distance of 25 mm A thin film light emitting layer was formed. Thereafter, an annealing treatment was performed at 1000 ° C. for one hour in the air. After the heat treatment, the phosphor thin film realized high-efficiency white light emission in both photoluminescence (PL) and cathodoluminescence (CL).

Then, an aluminum oxide (Al ₂ O ₃ ) insulating layer was formed on the light emitting layer thin film, and a metal Al electrode was further formed thereon to manufacture an EL element. When a 1-kHz sine-wave AC voltage was applied to the EL element, white EL light emission of color purity sufficiently endurable for practical use was realized. In addition, high-luminance white EL light emission that can withstand practical use was realized. As a result, the Tm, Eu, and Er co-doped gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor thin film sufficiently functioned as a light-emitting layer thin film for an EL element using a single crystal as a base.
(Example 3)

As a luminescent center material, thulium dioxide (Tm ₂ O ₃ ) powder, europium dioxide (Eu ₂ O ₃ ) powder, and erbium dioxide (Er ₂ ) as a luminescent center material in a powder obtained by mixing vanadium (V) with gadolinium (Gd) at 50 atomic%. After sufficiently mixing O ₃ ) powder with Gd to contain 1.0, 0.1 and 0.7 atomic%, respectively, and firing at 1000 ° C. for 1 hour in an argon (Ar) gas atmosphere. Thus, a Tm, Eu, and Er co-added gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor powder was produced. A sputtering target was prepared using the fired phosphor powder, and an antimony-added tin oxide (SnO ₂ : Sb) transparent electrode was grown on a quartz glass substrate, and an aluminum oxide (Al ₂ O ₃ ) insulating layer was grown thereon. Tm, Eu, and Er co-added gadolinium oxide-vanadium oxide multi-component oxidation under argon (Ar) gas, gas pressure of 6 Pa, sputtering power of 100 W, substrate temperature of 250 to 800 ° C., and substrate-target distance of 25 mm. A white light emitting phosphor thin film light emitting layer was formed. Thereafter, an annealing treatment was performed at 1000 ° C. for one hour in the air. After the heat treatment, the phosphor thin film realized high-efficiency white light emission in both photoluminescence (PL) and cathodoluminescence (CL).

Then, an aluminum oxide (Al ₂ O ₃ ) insulating layer was formed on the light emitting layer thin film, and a metal Al electrode was further formed thereon to manufacture an EL element. When a 1-kHz sine-wave AC voltage was applied to the EL element, white EL light emission of color purity sufficiently endurable for practical use was realized. In addition, high-luminance white EL light emission that can withstand practical use was realized. As a result, the Tm, Eu, and Er co-doped gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor thin film light-emitting layer thin film sufficiently functioned as a light-emitting layer thin film for an EL element based on quartz glass.
(Example 4)

Thulium dioxide (Tm ₂ O ₃ ) powder, europium dioxide (Eu ₂ O ₃ ) powder, and erbium dioxide (Er ₂ O) as emission center materials in a powder obtained by mixing vanadium (V) with gadolinium (Gd) at 50 atomic%. ₃ ) The powder is sufficiently mixed with Gd so as to contain 1.0, 0.1 and 0.7 atomic%, respectively, and then fired at 1000 ° C. for 1 hour in an argon (Ar) gas atmosphere. , Tm, Eu and Er co-added gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor powder was prepared. A sputtering target is prepared using the fired phosphor powder, and a sintered barium titanate (BaTiO ₃ ) ceramic substrate / insulator layer is provided with an argon (Ar) gas, a gas pressure of 6 Pa, a sputtering power of 100 W, and a substrate temperature. Under the conditions of 275 ° C. to 390 ° C. and a distance between the substrate and the target of 25 mm, a Tm, Eu, and Er co-added gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor thin film light emitting layer containing GdVO ₄ as a main component was formed. Thereafter, an annealing treatment was performed at 1020 ° C. for one hour in the air. After the heat treatment, the phosphor thin film realized high-efficiency white light emission in both photoluminescence (PL) and cathodoluminescence (CL).

Then, an aluminum-added zinc oxide (ZnO: Al) transparent electrode was formed on the light-emitting layer thin film, and a metal Al electrode was formed on the back surface, to produce an EL element. When a 1-kHz sine-wave AC voltage was applied to the EL element, white EL light emission of color purity sufficiently endurable for practical use was realized. In addition, high-luminance white EL light emission that can withstand practical use was realized. Thus, Tm mainly composed of GdVO _4, Eu, Er co-doped gadolinium oxide - vanadium multi-component oxide white-emitting phosphor thin film has sufficiently functions as a light emitting layer thin film EL device.

The invention's effect

According to the present invention, a new oxide phosphor capable of realizing high-brightness white color light emission by preparing a gadolinium oxide-vanadium oxide multi-element oxide base material and simultaneously adding Tm, Er and Eu as emission center materials. A thin film was realized. The thin-film phosphor was able to achieve high-luminance white light emission in any of photoluminescence (PL), cathodoluminescence (CL), and electroluminescence (EL). In particular, as a light emitting layer material for an EL element, high color purity can be realized, and in addition, the phosphor has extremely high chemical stability unique to an oxide. From the above, the thin-film phosphor can be widely applied as a phosphor for a thin-film EL element, a fluorescent lamp, a plasma display, a cathode ray tube, and the like, and the effect is enormous.

FIG. 3 is a diagram illustrating an example of an electroluminescence element. 1 {Transparent electrode layer ceramic sheet 2} Tm, Eu, Er co-doped gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor thin film layer 3} ‥‥‥‥‥‥ Ceramic sheet 4 ‥‥‥‥‥‥‥‥‥ Back electrode layer FIG. 3 is a diagram showing CIE chromaticity coordinates of EL light emission in Example 1. Luminance-applied voltage characteristics of thin-film EL element in Example 1

Claims (5)

A Gd-VO-based oxide containing gadolinium (Gd) and vanadium (V) as main components is used as a base material, and at least thulium (Tm), erbium (Er), and europium (Eu) are used as gadolinium (Gd) as emission center materials. ), Respectively, from 0.9 to 2.0 at%, 0.2 to 1.0 at% and 0.05 to 0.4 at%, preferably 1.0 to 1.5 at%, respectively. A gadolinium oxide-vanadium oxide multi-component oxide white light emitting phosphor characterized by containing 0.5 to 0.9 atomic% and 0.1 to 0.3 atomic%. The gadolinium oxide-vanadium oxide multi-component oxidation according to claim 1, characterized in that vanadium (V) in the base material is contained in an amount of 40 to 60 at%, preferably 45 to 55 at% based on gadolinium (Gd). Object white light emitting phosphor. Vanadium multi-component oxide - gadolinium oxide of the claims 1 and 2 wherein the matrix material is characterized in that it is a composite oxide containing vanadium厶and gadolinium oxide _{(Gd 2 O 3) (V} 2 O 5) White light emitting phosphor. 4. The gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor according to claim 1, wherein the base material is GdVO ₄ which is a ternary compound. A white light-emitting thin-film electroluminescent device, wherein a thin film of the gadolinium oxide-vanadium oxide multi-component oxide white light-emitting phosphor according to claim 1 is used as a light-emitting layer.

Images