JP2010006664A - Green fluorescent glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide new fluorescent glass exhibiting green fluorescence with high luminance even when being excited with ultraviolet light having a wavelength of ≥365 nm by a UV light emitting diode (LED), and also having excellent durability. <P>SOLUTION: The fluorescent glass emitting a green light by being excited by ultraviolet light contains, by mol, ≥85% SiO<SB>2</SB>, 0.04-0.75% Tb, 0.09-1.5% Ce and a rare earth element 0-2 times of Tb quantity, is obtained by firing porous glass and is characterized in that the content of Ce is larger than that of Tb. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fluorescent glass that emits green light when excited by ultraviolet rays, and particularly relates to a fluorescent glass that emits green light with high brightness even when irradiated with ultraviolet rays having a wavelength of 350 nm or more.

In recent years, ultraviolet light emitting diodes (LEDs) with an emission wavelength of 365 nm to 380 m have been mass-produced at a low price, and there has been a demand for mercury-free light sources. The use as is expected. However, LED is a point light source,
In order to obtain a long-life planar light source, a fluorescent plate that converts ultraviolet light into a visible surface is required. Glass is a material having high ultraviolet transmittance, good durability and excellent stability, but generally has low luminance and is considered unsuitable for use as a light source.

On the other hand, it has been reported that a fluorescent glass with high brightness can be obtained by improving the glass composition and changing the structure of the center of the rare earth element that is the emission center. For example, as a high-intensity fluorescent glass, fluorophosphate fluorescent glass containing 0.8 to 8% Tb and 0 to 0.2% Ce (see Patent Document 1 below), 0 to 6.5% Tb and 0 to 0.2% Ce Fluorophosphate fluorescent glass (see Patent Document 2 below), fluoride glass (see Patent Document 3 below) having a Tb ³⁺ concentration of 5 to 25 mol% and a Ce ³⁺ concentration of 0.05 mol% to 10 mol% are known. Yes. However, the fluoride glass and fluorophosphate glass used in these fluorescent glasses require a special environment for melting, and thus the manufacturing process is complicated, and the water resistance is inferior. Not suitable for use.

In addition, oxide glass containing Tb or Eu as a fluorescent agent in borosilicate glass containing ₂ to 60 mol% of SiO ₂ and 5 to 70 mol% of B ₂ O ₃ exhibits strong fluorescence in the visible region when irradiated with ultraviolet rays. Has also been reported (see Patent Document 4 below). However, this oxide glass is insufficient in durability. For example, when used for adjusting the laser optical axis of an excimer laser or the like, the oxide glass is gradually deteriorated and cannot exhibit sufficient durability.

In addition, it is known that a high-intensity ultraviolet-excited fluorescent glass can be obtained by doping a rare earth and a sensitizer into porous glass mainly composed of chemically stable silica and baking it (Patent below). Reference 5). Furthermore, fluorescent glass co-doped with Tb and Ce has also been reported (see Non-Patent Document 1 below). However, these glasses emit light with high efficiency when excited with ultraviolet light of 300 nm or less, but when excited with ultraviolet light having a wavelength of about 365 nm to 380 m by an ultraviolet LED, emission with extremely low luminance is obtained. Only.

Patent Document 6 below describes a method for producing a glass that emits green light by introducing an element such as Tb, Gd, Y, or Ce into a porous glass and then firing it. However, the glass having the composition specifically described in this document can only obtain low fluorescence intensity at an excitation wavelength of 350 nm or more, and further emits light in the wavelength region of 400 to 450 nm, and emits green light. Color purity is reduced.

Non-Patent Document 2 below describes a method for producing a fluorescent glass in which Tb and Ce are co-doped by a sol-gel method. However, in this method, in order to use alkoxide as a raw material, it is necessary to increase the brightness by performing a high temperature treatment in hydrogen gas after baking in air or oxygen, and the manufacturing process is complicated. Moreover, since the obtained glass has a large extinction coefficient in the near ultraviolet to visible short wavelength region, the ultraviolet rays do not penetrate into the glass, and the glass is colored. Furthermore, for the excitation spectrum obtained, the peak wavelength is at 330 nm, 365-380 nm
When excited with about ultraviolet rays, sufficient light emission intensity cannot be obtained.
JP 9-206422 A JP-A-8-133780 JP 2006-298743 A JP-A-10-167755 JP2004-224686A CN1736920A W. Liu, DP. Chen, H. Miyoshi, K. Kadono and T. Akai, J. Non-Cryst. Solids, 352 (28-29), 2969 (2006). GE Malashkevich, GI Semkova, AP Stupak and AV Sukhodolov, Phys.Solid State, 46 (8), 1425 (2004).

  The present invention has been made in view of the above-mentioned problems of the prior art, and its main purpose is to produce high-intensity green fluorescence even when excited by ultraviolet light having a wavelength of 365 nm or more by an ultraviolet light emitting diode (LED). It is another object of the present invention to provide a novel fluorescent glass exhibiting excellent durability.

The present inventor has intensively studied to achieve the above-described object. As a result, the glass obtained by doping the porous glass mainly composed of silica with Tb and Ce, and further diluting elements if necessary at a specific ratio, and firing in a reducing atmosphere has a wavelength of It has been found that even when excited by ultraviolet light having a long wavelength of about 350 nm or more, in particular, ultraviolet light of 365 nm or more by an ultraviolet light emitting diode, the fluorescent glass exhibits high-intensity green fluorescence and excellent in transparency. The present invention has been completed as a result of further research based on such knowledge.

That is, the present invention provides the following fluorescent glass that emits green light and a method for producing the same.
1. A glass containing 85 mol% or more of SiO ₂ , 0.04 to 0.75 mol% of Tb, 0.09 to 1.5 mol% of Ce, and 0 to 2 times mol of a dilution element with respect to the amount of Tb, and firing the porous glass A fluorescent glass that emits green light by excitation with ultraviolet rays, characterized in that the Ce content is greater than the Tb content.
2. The dilution element is selected from the group consisting of Li, B, Na, Mg, Al, P, K, Ca, Zn, Ga, Ge, Rb, Sr, Y, Zr, Sn, Cs, Ba, La, Gd and Tl Item 2. The fluorescent glass according to Item 1, which is at least one kind.
3. Item 3. The fluorescent glass according to Item 1 or 2, wherein the total content of Ce and diluting elements is at least twice as much as the Tb content.
4). Item 4. The fluorescent glass according to any one of Items 1 to 3, which is excited by ultraviolet rays having a wavelength of 350 nm or more and emits green light with high luminance.
5). Any one of the above items 1 to 4, wherein the porous glass mainly composed of SiO ₂ is doped with Tb, Ce and, if necessary, a dilution element, and then fired in a reducing atmosphere. The manufacturing method of fluorescent glass which emits green light of description.
6). Item 6. The method for producing fluorescent glass according to Item 5, wherein the porous glass is a porous body containing 90 mol% or more of SiO ₂ and having continuous pores having an average pore diameter of 1 to 10 nm.
7). Item 7. The method according to Item 5 or 6, wherein baking is performed at a temperature of 950 ° C or higher.

  Hereinafter, the fluorescent glass of the present invention and the manufacturing method thereof will be described in detail.

Method for Producing Fluorescent Glass The fluorescent glass of the present invention can be produced by doping Tb and Ce into a porous glass containing SiO ₂ as a main component and then baking it in a reducing atmosphere. Hereinafter, this manufacturing method will be described.

(1) Porous glass The porous glass used in the method for producing a fluorescent glass of the present invention may be a porous glass mainly composed of SiO ₂ , and particularly contains about 90 mol% or more of SiO _2. The content is preferably about 95 mol% or more. In the porous glass, SiO
Components other than ₂ may contain elements such as Al and B depending on the production method.

The shape of the pores in the porous glass is preferably continuous pores so that ions can be introduced from the outside into the inside. The pore diameter is preferably about 1 nm to 10 nm, and 2 nm to 6 nm.
More preferably, it is about. By using a porous glass having a pore diameter in this range, an element described later can be uniformly doped to the inside of the glass, and a phosphor having high luminance can be obtained. If the pore diameter is too small, the probability that Tb and Ce will be adjacent to each other decreases, resulting in a decrease in luminance. On the other hand, if the pore size is too large, the glass after firing tends to become opaque, and further, cracks are likely to occur during firing. . In this case, the pore diameter is a value obtained by the BET method using the nitrogen adsorption method.

  In the case of producing a flat phosphor, the thickness of the porous glass is preferably about 0.3 mm to 2.5 mm, and about 0.5 to 2 mm in order to obtain a phosphor that emits light uniformly. Is more preferable. If the porous glass is too thick, the distribution of the doped element tends to be non-uniform, while if it is too thin, cracking tends to occur during firing, which is not preferable.

It does not specifically limit about the method of manufacturing porous glass, What is necessary is just the method which can manufacture porous glass which satisfies above-described conditions. For example, it can be obtained by a method in which borosilicate glass is spinodal phase-separated into a boric acid phase and a silica phase, and the boric acid phase is leached with an acid to obtain porous silica. This method is particularly advantageous in that the pore diameter and surface area can be freely changed, and is commercially available, for example, as Vycor glass (trade name). These commercially available products generally contain about 95 mol% or more of SiO ₂ , and in addition, impurities such as Al and B are generally present in a small amount.

(2) Doping process of additive element In the fluorescent glass of the present invention, Tb and Ce are used as elements to be doped into the porous glass. Among these, Tb is an element that becomes a light emission center, and is an essential element for green light emission. Ce is an element that acts as a sensitizer.

  Furthermore, in the fluorescent glass of the present invention, in addition to the above-described Tb and Ce, a dilution element can be added as necessary. The diluting element can be used without particular limitation as long as it is colorless and does not emit fluorescence and can be easily introduced into the porous glass. For example, Li, B, Na, Mg, Al, P, K, Ca, Zn, Ga, Ge, Rb, Sr, Y, Zr, Sn, Cs, Ba, La, Gd, Tl, etc. Two or more kinds can be mixed and used.

The method for doping each element described above is not particularly limited, and for example, a method of doping by a vapor phase method such as a CVD method, a method of immersing porous glass in a solution containing the element described above, and the like can be applied. In particular, the method of immersing in a solution is advantageous in that the element is easily uniformly doped.

In the method of immersing the porous glass in the solution, it is sufficient that each element can be doped so as to be in the concentration range of each element in the fluorescent glass described later. The concentration of each element in the solution is not particularly limited. For example, the concentration of Tb is usually preferably about 0.01 mol / L to 3 mol / L, preferably about 0.1 mol / L to 1 mol / L. More preferably. Ce is 0.1 to 2.5
About mol / L is preferable, and about 0.2 to 1.5 mol / L is more preferable. In addition, when doping diluted elements, the concentration of these elements is preferably about 0.05 to 2.5 mol / L, and more preferably about 0.1 mol / L to 1 mol / L.

  As a solvent for the solution, water is usually used, but organic solvents such as ethanol and acetone can also be used as appropriate. When water is used as a solvent, each element may be dissolved in water as a water-soluble compound such as nitrate or chloride.

  As a specific dipping method, the porous glass may be dipped in a solution containing each of the above elements and allowed to stand. The temperature of the solution may be about room temperature, and the immersion time may be about 2 minutes to 60 minutes.

(3) Firing step After immersing the porous glass in a solution containing each of the elements described above, the porous glass is taken out from the solution and baked at 950 ° C or higher.

Usually, after removing the porous glass from the solution, the temperature is slowly raised to about 350 ° C. over several hours and dried. Care should be taken because the glass may break if the heating time is too early. When nitrate is used as the raw material, nitrate is decomposed, but in order to avoid a rapid reaction with the reducing agent, drying in air or an inert gas is preferred. After drying, it is usually once cooled to room temperature.

Next, the glass is densified by firing at 950 ° C. or higher in a reducing atmosphere. The firing temperature is preferably about 950 ° C to 1200 ° C, more preferably about 1000 to 1150 ° C. If the baking temperature is too low or too high, sufficient fluorescence intensity cannot be obtained, which is not preferable. The firing time may normally be about 0.5 to 2 hours.

In the firing step, a temperature lower by about 50 to 200 ° C. than the firing temperature, preferably 100 to 150 ° C.
It is preferable that the temperature is about 900 to 1050 ° C., preferably about 930 to 1000 ° C., held for about 0.5 to 2 hours, and then heated to the above baking temperature for baking. . Thereby, a brightness | luminance can be improved more.

  The time required to heat the glass after drying to the above holding temperature is usually preferably about 3 to 20 hours, more preferably about 4 to 10 hours.

  The atmosphere during firing needs to be a reducing atmosphere in order to reduce Ce to trivalent. For example, a reducing atmosphere can be obtained by putting carbon powder in an airtight container and baking it. In addition, a method of reducing by flowing nitrogen gas containing hydrogen or the like in an atmosphere adjustment furnace can be employed.

  At the time of firing, the glass is warped by heating by placing the porous glass on the ceramic flat plate and further placing the ceramic flat plate thereon. The material of the ceramic flat plate is not particularly limited, and alumina or the like can be used. In order to prevent cracking due to shrinkage of the glass during firing, it is desirable that the surface of the ceramic flat plate be free of irregularities.

Fluorescent glass The fluorescent glass of the present invention can be produced by the above-described production method, contains SiO ₂ at 85 mol% or more, Tb at 0.04 to 0.75 mol%, and Ce at 0.09 to 1.5 mol%, and has a Ce content. More than the Tb content. Tb and Ce are usually present as oxides in the fluorescent glass of the present invention.

  In particular, the Tb content is preferably about 0.1 to 0.75 mol% in order to produce high-luminance green light emission with high purity.

The fluorescent glass is one in which Tb and Ce are uniformly dispersed and fixed in the above-described concentration range in a mother glass mainly composed of SiO ₂ obtained by firing porous glass. Among these components, Tb is an element that becomes a light emission center that generates green fluorescence by ultraviolet excitation. When the Tb content is too low, it is difficult to obtain sufficient fluorescence intensity. On the other hand, when the Tb content is too high, the brightness decreases due to concentration quenching, and the glass tends to be devitrified. . Ce acts as a sensitizer for increasing the luminance of green light emission. If the Ce content is too low, sufficient luminance cannot be obtained, while the Ce content is too high. And the emission color is blue.

  A dilution element can be further added to the fluorescent glass of the present invention as necessary. The diluting element can be used without particular limitation as long as it is colorless and does not emit fluorescence and can be easily introduced into the porous glass. For example, Li, B, Na, Mg, Al, P, K, Ca, Zn, Ga, Ge, Rb, Sr, Y, Zr, Sn, Cs, Ba, La, Gd, Tl, etc. Two or more kinds can be mixed and used. These diluting elements have functions of preventing concentration quenching due to adjacent Tb elements, suppressing blue light emission by Ce, and helping to increase the excitation wavelength by Ce. For this reason, the content of Ce can be reduced by adding these dilution elements.

  The content of the diluting element is set to about 2 times or less the Tb content. That is, the content of the diluting element is in the range of about 0 to 2 moles relative to the Tb content. If the content of the dilution element exceeds this range, the glass becomes opaque, which is not preferable.

  In the fluorescent glass of the present invention, the total content of the above-described dilution element and Ce content is preferably 2 times mol or more, more preferably 2.5 times mol or more of the Tb content. preferable. That is, when the diluent element is not included, the Ce content may be at least twice as much as the Tb content. When the diluent element is included, the total content of the diluent element and Ce is 2 times the Tb content. What is necessary is just to be more than double mole. By satisfying the above conditions, concentration quenching due to the adjacent Tb elements can be prevented.

  In order to obtain a glass having particularly good transparency, the value obtained by adding the Tb content and the content of the additive element to twice the Ce content is preferably 1.0 or less.

  The fluorescent glass of the present invention only needs to contain each element in the above-described concentration range, and in addition to the above-described components, elements such as Al and B may be contained depending on the production method of the porous glass. .

The fluorescent glass of the present invention emits green light with high luminance by containing each element in combination in the concentration range described above. In addition, the glass of the present invention contains SiO ₂ at a high concentration, is highly transparent, is not susceptible to defects caused by ultraviolet irradiation, and has excellent durability and can be used stably for a long period of time.

The fluorescent glass of the present invention is a glass exhibiting green fluorescence having a high intensity and a wavelength of about 543 nm by ultraviolet excitation, and can be a glass having a low emission intensity of about 450 nm or less and a high green purity. As the excitation light, for example, ultraviolet rays having a wide wavelength range of about 200 to 380 nm can be used. The fluorescent glass of the present invention can emit green light with high brightness even when long wavelength ultraviolet light having a wavelength of about 350 nm or more, especially ultraviolet light having a wavelength of about 365 nm to 380 nm by an ultraviolet LED is used as excitation light. It has excellent performance.

As described above, the fluorescent glass of the present invention is a fluorescent glass that emits green light with high luminance even by ultraviolet rays having a long wavelength of 350 nm or more, and has excellent durability with little deterioration due to ultraviolet rays. Therefore, by combining the fluorescent glass of the present invention with an ultraviolet LED that is a solid state light emitting device, a long-life illumination and display device can be produced.

  Further, among the fluorescent glasses of the present invention, those having good transparency are transparent when not irradiated with ultraviolet rays. Therefore, taking advantage of this feature, for example, a transparent sign that emits light only at night, a field sequential It can be used for LCD R, G, B switching backlight. Furthermore, since it has high water resistance, there is an advantage that it can be used outdoors when used as an illumination light source.

  Furthermore, since the fluorescent glass of the present invention has a low Tb content, the cost is lower when compared with a conventional fluorescent glass having the same brightness.

In addition, the fluorescent glass of the present invention generates fluorescence with ultraviolet rays of 191 nm to 351 nm, and therefore can be used for excimer laser position adjustment. In particular, since it is a glass mainly composed of silica, it has an advantage that it is less deteriorated by ArF excimer laser irradiation.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1
Porous glass (10 × 10 × 2 mm) having an SiO ₂ content of 99 mol% and an average pore diameter of 4 nm was used as a raw material, and this was used in the aqueous solution described in each item of the present invention products 1 to 5 in Table 1 below. It was immersed for 5 minutes at 25 ° C., then taken out of the aqueous solution, heated to 350 ° C. over 3 hours and dried. In addition, each element described in Table 1 was added as a nitrate.

Thereafter, the porous glass dried by the above-described method was heated to 1000 ° C. in an alumina container with a lid containing carbon powder for 5 hours, held at this temperature for 1 hour, and then further 1120 over 1 hour. The glass was produced by heating to 0 ° C. and sintering for 1 hour. The content of each element in each obtained glass is shown in Table 1 below. The balance was Al ₂ O ₃ 0.4 mol% and Na ₂ O 0.2 mol%.

Each obtained glass was placed on a fluorescent lamp (4 W) having a wavelength of 365 nm, and the emission color and transparency were visually observed. At this time, the ultraviolet intensity was measured with a UV meter and found to be 3.6 mW / cm ² .

  The emission color, brightness, and transparency of each glass are shown in Table 1 below.

The glasses of the present invention products 1 to 5 described above were glasses that had a Ce concentration higher than twice the Tb concentration, were transparent to translucent and had high luminance, and emitted green light. In addition, the glass of the products 1 and 2 of the present invention having a Tb content of less than 0.1 mol% had a slightly bluish green emission color.

Example 2
Porous glass (10 × 10 × 2 mm) having a SiO ₂ content of 99 mol% and an average pore diameter of 4 nm was used as a raw material, and this was used for each item of the present invention products 6 to 11 and comparative products 1 to 4 in Tables 2 and 3 below. A fluorescent glass was produced in the same manner as in Example 1 except that the glass was immersed in the aqueous solution described in 5 at 25 ° C. for 5 to 20 minutes.

Each obtained glass was placed on a fluorescent lamp (4 W) having a wavelength of 365 nm, and the luminance and transparency were visually observed. At this time, the ultraviolet intensity was measured with a UV meter and found to be 3.6 mW / cm ² .

  Further, the emission intensity was measured for the case of excitation with a fluorescent lamp with a wavelength of 355 nm and the case with excitation with a fluorescent lamp with a wavelength of 254 nm, and the intensity ratio was determined.

  The results are shown in Tables 2 and 3 below.

  As is clear from the above results, the glasses 6 to 11 of the present invention are all transparent or translucent and have high luminance and emit green light.

On the other hand, Comparative products 1 to 3 in which the Ce content is lower than the Tb content have low luminance, and the emission intensity at 355 nm in the excitation spectrum is lower than the emission intensity at 254 nm excitation. It can be seen that the intensity of green light emission due to is low. Further, the comparative product 4 having a Ce content less than twice the T content and containing no diluting element had a low emission intensity, and the emission of blue light due to Ce became strong.

  In addition, about this invention products 6-8, the value which added the value of Tb and Gd content to twice Ce content was 1.0 or less, and became glass with high transmittance.

Further, for the glass of the product 7 of the present invention, FIG. 1 shows an excitation spectrum of fluorescence having an emission wavelength of 543 nm. It can be seen that the peak of the excitation spectrum exists in the vicinity of 350 nm, and that sufficient fluorescence intensity is exhibited even with excitation with a wavelength of 365 nm or more.

  FIG. 2 shows an emission spectrum at an excitation wavelength of 350 nm. The peak of the emission spectrum was in the vicinity of 545 nm, and the emission intensity of 400 to 450 nm by Ce was a low value.

Example 3
Porous glass (80 × 80 × 2 mm) having an SiO ₂ content of 99 mol% and an average pore diameter of 4 nm was used as a raw material, and this was made from 0.1 mol / L of Tb (NO ₃ ) ₃ .5H ₂ O, Gd (NO ₃ ) It was immersed in an aqueous solution containing 0.1 mol / L of ₃ · 6H ₂ O and 0.3 mol / L of Ce (NO ₃ ) ₃ · 6H ₂ O at 25 ° C. for 5 minutes. The temperature was raised to 350 ° C. in the air over time, and drying was performed.

  Thereafter, in a alumina container with a lid containing carbon powder, a sandwiched porous glass plate was placed between two 100 × 100 × 2 mm SSA-S alumina plates and 1000 ° C. over 5 hours. The temperature was raised to 1,120 ° C. for 1 hour, and further heated to 1120 ° C. over 1 hour and sintered for 1 hour.

By the above-described method, a green fluorescent glass plate (invention product 12) without warping was obtained. Its _{composition, SiO 2 98.7mol%, Al 2} O 3 0.3mol%, Na 2 O 0.3mol%, TbO 1.5 0.15mol%, CeO 2 0.40mol%, was GdO _1.5 0.15 mol%. The obtained glass plate was colorless and showed slight scattering, and the visible light transmittance per 1 mm thickness was 70% at 425 nm and 87% at 600 nm. The luminance on the 365 nm UV lamp was 600 cd / m ² .

Example 4
Porous glass (10 × 10 × 1.5 mm) having an SiO ₂ content of 99 mol% and an average pore diameter of 4 nm was used as a raw material, and this was made from 0.1 mol / L of Tb (NO ₃ ) ₃ .5H ₂ O, Ce (NO ₃ ) Immerse it in an aqueous solution containing 0.3 mol / L of ₃ · 6H ₂ O and 0.1 mol / L of the nitrate of the dilution element shown in Tables 4 and 5 below at 20 ° C., and then remove it from the aqueous solution. Then, the temperature was raised to 350 ° C. in the air over 3 hours, and drying was performed.

  Thereafter, the temperature was raised to 1000 ° C. over 5 hours in an alumina crucible with a carbon powder and held at this temperature for 1 hour, and then heated to 1120 ° C. over 1 hour and sintered for 1 hour. Glass was produced. The contents of each element in each obtained glass are shown in Tables 4 and 5 below.

Each glass obtained was placed on a fluorescent lamp (4 W) having a wavelength of 365 nm, and the luminance was measured. Each glass showed a green color with high brightness. The measurement results of luminance are shown in Tables 4 and 5 below.

6 is a graph showing an excitation spectrum at an emission wavelength of 543 nm in the glass of the product 7 of the present invention in Example 2. 6 is a graph showing an emission spectrum at an excitation wavelength of 350 nm in the glass of Product 7 of the present invention in Example 2.

Claims (7)

A glass containing 85 mol% or more of SiO ₂ , 0.04 to 0.75 mol% of Tb, 0.09 to 1.5 mol% of Ce, and 0 to 2 times mol of a dilution element with respect to the amount of Tb, and firing the porous glass A fluorescent glass that emits green light by excitation with ultraviolet rays, characterized in that the Ce content is greater than the Tb content. The dilution element is selected from the group consisting of Li, B, Na, Mg, Al, P, K, Ca, Zn, Ga, Ge, Rb, Sr, Y, Zr, Sn, Cs, Ba, La, Gd and Tl The fluorescent glass according to claim 1, which is at least one kind. The fluorescent glass according to claim 1 or 2, wherein the total content of Ce and diluting elements is at least twice as much as the Tb content. The fluorescent glass according to any one of claims 1 to 3, which emits green light with high brightness when excited by ultraviolet rays having a wavelength of 350 nm or more. The porous glass containing SiO ₂ as a main component is doped with Tb, Ce, and, if necessary, a diluting element, and then fired in a reducing atmosphere. The manufacturing method of fluorescent glass which emits green light of description. The method for producing a fluorescent glass according to claim 5, wherein the porous glass is a porous body containing 90 mol% or more of SiO ₂ and having continuous pores having an average pore diameter of 1 to 10 nm. The method according to claim 5 or 6, wherein baking is performed at a temperature of 950 ° C or higher.

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