JPH0595132A - Infrared visible conversion device and manufacturing method - Google Patents

Abstract

PURPOSE:To provide device that produces a conversion image with good resolution, a high S/N, and high infrared visible conversion efficiency, by using as a material infrared stimulated phosphor, consisting of a single or mixed crystal made of CaS, SrS, CaSe, and SrSe as a phosphor base material with the GaAs substrate. CONSTITUTION:An infrared stimulated phosphor layer 2 is formed on a GaAs substrate 1 in an infrared visible conversion device. In the infrared stimulated phosphor material, at least two elements Ce and Sm or at least two elements Ce and Sm, are added to the phosphor base material. In this case, a single or mixed crystal made of CaS, SrS, CaSe, and SrSe is used as the phosphor base material. While the substrate 1 is heated at temperatures above 300 deg.C and with gas partial pressure over 1X10-<8>Torr by a conducted H2S or H2Se gas, the infrared stimulated phosphor layer 2 is formed after a surface treatment step for the substrate 1 is carried out in a device manufacturing step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared-visible conversion element and a method for manufacturing the same, and more particularly, to a red image which has a high resolution and a high infrared-visible conversion efficiency and which can obtain a converted image with a high S / N ratio. The present invention relates to an outer-visible conversion element and a manufacturing method thereof.

[0002]

An infrared stimulable phosphor is a fluorescent substance which emits light in the visible range when irradiated with infrared light after being irradiated with light of short wavelength, X-rays, radiation or the like in advance. A phosphor obtained by adding two or more kinds of rare earth elements such as europium (Eu) and samarium (Sm) or cerium (Ce) and Sm to a sulfide or selenide of a group of metals may be the phosphor with the highest infrared-visible conversion efficiency. Are known.

An infrared-visible conversion element using such an infrared stimulable phosphor is prepared by mixing phosphor powder with a binder or the like and coating it on a substrate such as glass, or a phosphor dispersed in the binder. It has a structure in which powder is sandwiched between a pair of polymer films and is used for detecting semiconductor laser light, adjusting optical systems, and the like.

In recent years, optical communication technology and optical information processing technology using a semiconductor laser have been developed, and it is necessary to detect infrared light emitted from the semiconductor laser with higher accuracy than before and a mode pattern of the laser light. The need to inspect optical information in dimensions is growing. However, in the device having the conventional structure, since the powder phosphor is used, there is a drawback that the light is scattered by the phosphor particles and the resolution is lowered,
It was impossible to adjust the optical axis with high accuracy and inspect the mode pattern of the semiconductor laser light.

Therefore, the present inventors have reduced the light scattering by thinning the phosphor by using a thin film forming technique such as a vacuum vapor deposition method, a sputtering method or a CVD method for the purpose of achieving high resolution of the device. I tried to achieve it. However, when a thin film is formed using an amorphous substrate such as glass as the substrate, the thin film becomes a polycrystalline film that is an aggregate of microcrystals (hereinafter referred to as crystallites), and thus light scattering also occurs. , It was difficult to improve the resolution sufficiently.

When an infrared image is visualized by using an infrared-visible conversion element in which an infrared stimulable phosphor layer is formed on a transparent substrate, the infrared light is observed from the side opposite to the observation direction. And a transmission method for forming an image on the phosphor layer and observing the image,
There is a reflection method in which infrared light is incident from the observation direction side to form an image on the phosphor layer to observe the image, but in both the transmission method and the reflection method, infrared-visible conversion is performed from the side opposite to the observation direction. Visible light passes through the device and acts as noise, which has the drawback of significantly reducing the S / N ratio when observing infrared-visible converted images.

[0007]

As described above, the prior art has left many problems despite various efforts.

An object of the present invention is to solve the problems of the above-mentioned prior art and to obtain a converted image having a high resolution and a high infrared-visible conversion efficiency and a high S / N ratio. It is to provide a visible light conversion element and a manufacturing method thereof.

[0009]

Means for Solving the Problems The above-mentioned object is to provide an infrared-visible conversion device comprising an infrared stimulable phosphor layer formed on a gallium arsenide (GaAs) substrate, wherein the infrared stimulable phosphor is An infrared stimulable phosphor in which at least two kinds of elements of Eu and Sm, or at least two kinds of elements of Ce and Sm are added to the body matrix, and the above-mentioned phosphor matrix is calcium sulfide (CaS). , Strontium sulfide (SrS), calcium selenide (CaSe), strontium selenide (SrSe), or an infrared-visible conversion element that is a mixed crystal thereof, and a red color on a GaAs substrate. In the production of an infrared-visible conversion element formed by forming an external stimulable phosphor layer, the above-mentioned substrate is heated to 300 ° C. or higher, and sulfurization is performed so that the gas partial pressure at the substrate position becomes 1 × 10 to ⁸ Torr or higher. by introducing hydrogen (H ₂ S) gas or hydrogen selenide (H ₂ Se) gas It can be achieved by using a method of forming an infrared accelerated phosphorescence fluorescent layer after the surface treatment of the substrate.

[0010]

1 is a cross-sectional view showing a schematic structure of the infrared-visible conversion device of the present invention, showing that it comprises a GaAs substrate 1 and an infrared stimulable phosphor layer 2 formed on the substrate 1.

At present, GaAs is already used in semiconductor devices and the like, and a single crystal having few defects and good crystallinity has been obtained. Therefore, when the phosphor layer is formed on the GaAs substrate, a phosphor thin film that is homogeneous and has few defects can be formed over the entire substrate.

FIG. 2 is a diagram showing the relationship between the lattice constant of GaAs and the lattice constants of CaS, SrS, CaSe, and SrSe which are the phosphor matrix. As is clear from the figure, the lattice constant of CaS and
The difference from the lattice constant of GaAs is small, and the highest quality single crystal film is obtained when CaS is used as the matrix of the infrared stimulable phosphor. Although the difference in lattice constant is relatively large for other phosphor host materials, the results of repeated experiments showed that CaS, SrS, CaSe, SrS on GaAs substrates using the manufacturing method of the present invention.
When a thin film made of any one of e or a mixed crystal thereof is formed, the growth direction is defined by the substrate plane orientation, and a polycrystalline film or a single crystal film with a uniform growth direction can be obtained. Became clear. For this reason,
The obtained crystal film has excellent smoothness, light scattering is extremely small, and thus extremely high resolution can be obtained. In addition, since there are very few defects in the film as compared with a polycrystalline state in which the growth directions are not uniform, the infrared-visible conversion efficiency of the phosphor becomes extremely high.

Further, the fundamental absorption wavelength of GaAs is about 0.83 μm, and light of 0.83 μm or less is not transmitted. Therefore, when using the transmissive infrared-visible conversion element of the present invention, only infrared light necessary for infrared-visible conversion is transmitted through the substrate, and reaches the phosphor layer to be converted into visible light. The converted image can be observed with good contrast without being disturbed by visible light noise. Even when the reflective infrared conversion device of the present invention is used, since the GaAs substrate is black, the converted image has a high contrast and is easy to observe.

Next, it will be explained that the crystallinity is remarkably improved when the method of the present invention is used in the production of the infrared-visible conversion element of the present invention. The surface of the GaAs substrate after being subjected to normal cleaning treatment is covered with an oxide film.
Although As must be supplied by heating to ℃ or more to remove the surface oxide film and at the same time to prevent As desorption, the oxide film can be removed at a low temperature by using the method of the present invention.
Since it is not necessary to supply s, contamination of the phosphor by As can be prevented, and at the same time, a high quality phosphor film can be formed.

FIG. 3 (a) is a diagram showing the relationship between the substrate temperature and the half-width of the X-ray rocking curve during the surface treatment with H ₂ S when the CaS film is formed on the GaAs (111) substrate. The H ₂ S partial pressure at this time is 1 × 10 to ⁸ Torr. Here, the X-ray rocking curve full width at half maximum serves as an index showing the good crystallinity, and the smaller this numerical value, the better the crystallinity. When the crystallinity is improved, the surface flatness of the device is improved, the resolution is increased, and the defects are reduced, so that the conversion efficiency is also increased. From the results shown in the figure, when the substrate temperature is 300 ° C or higher, X
The line rocking curve full width at half maximum is significantly reduced, and it is clear that the method of the present invention has a great effect on improving the crystallinity, that is, improving the resolution of the device and improving the conversion efficiency.
Further, this effect was the same when the infrared stimulable phosphor layer was formed after the surface treatment with H ₂ Se. That is, FIG.
(b) H ₂ S when a CaS film is formed on a GaAs (111) substrate
FIG. 6 is a diagram showing the relationship between the substrate temperature and the X-ray rocking curve half width during surface treatment with e. The H ₂ Se partial pressure at this time is 1 × 10 to ⁸ Torr. From the results in the figure, in this case as well, H ₂
Similar to the case of the S treatment, the half width of the X-ray rocking curve is remarkably reduced at the substrate temperature of 300 ° C. or higher, and the method of the present invention has a great effect on improving the crystallinity, that is, improving the resolution of the device and improving the conversion efficiency. You can see that

Further, FIG. 4 (a) shows that CaS is formed on a GaAs (111) substrate.
FIG. 6 is a diagram showing the relationship between the H ₂ S partial pressure during surface treatment with H ₂ S when a film is formed and the half-width of the X-ray rocking curve of the CaS film. At this time, the substrate surface temperature was 300 ° C. From the results in the figure, it is understood that the half-width of the X-ray rocking curve is remarkably reduced at the H ₂ S partial pressure of 1 × 10 to ⁸ Torr or more, and the method of the present invention has a great effect on the improvement of crystallinity. Similar results were obtained when the surface treatment gas was H ₂ Se. The results are shown in Fig. 4 (b).

When the substrate surface treated by the method of the present invention was inspected by Auger electron spectroscopy, no oxygen signal was detected, and the method of the present invention is effective in removing the surface oxide film. It was also made clear.

[0018]

EXAMPLES The infrared-visible conversion element of the present invention and the method for producing the same will be specifically described below with reference to examples.

[0019]

EXAMPLE 1 In FIG. 1, an infrared-visible conversion device having a structure in which a substrate 1 is a GaAs single crystal substrate having a plane orientation of (111) and a phosphor layer 2 is a CaS phosphor layer containing Eu and Sm. Will be described.

In the fabrication of this element, first, the GaAs substrate 1 is washed with pure water, trichlene, etc., then immersed in an ammonium sulfide solution for surface stabilization treatment, washed again with pure water and dried. It is installed in a molecular beam epitaxy system and exhausted to 10 to ⁸ Torr or less. While heating the substrate to 300 ° C, the flow rate of H ₂ S gas is controlled by a mass flow controller.
The substrate was irradiated while adjusting to 10 sccm. At this time, the H ₂ S partial pressure at the substrate position was 7 × 10 to ⁶ Torr. In this state, after the substrate surface treatment for 10 minutes, the substrate temperature was raised to 500 ° C and the CaS phosphor layer 2 containing Eu and Sm was added to 20 μm.
Formed on the substrate 1. Here, in the formation of the phosphor layer 2, Ca metal, Eu metal, and Sm metal, which are filled in different evaporation sources, are adjusted and heated and evaporated so that the Eu concentration is 500 ppm and the Sm concentration is 150 ppm. It was carried out by irradiating the substrate 1 with H ₂ S gas at the same time as depositing it on the substrate 1. The thin film formation rate at this time was 50 nm / min.

The CaS phosphor layer 2 formed as described above was inspected by using a reflection electron beam diffractometer, an X-ray diffractometer and a transmission electron microscope. As a result, it was confirmed that it was a single crystal film epitaxially grown on the substrate 1. Was done. Further, when the surface roughness was measured using a stylus type surface roughness meter, it was confirmed that the surface roughness was 10 nm or less and that the film was an extremely smooth film.

Table 1 shows the infrared-visible conversion efficiency and resolution of the infrared-visible conversion element prepared as described above and the infrared-visible conversion element prepared by forming the phosphor layer on the glass substrate. It is the table shown in comparison. From this result, it is understood that the infrared-visible conversion element of the present invention has a higher infrared-visible conversion efficiency and a higher resolution than the infrared-visible conversion element having the conventional structure. Further, since the device of the present invention uses the GaAs substrate and noise due to visible light is not superimposed, an image with extremely high contrast was obtained.

[0023]

[Table 1]

[0024]

Example 2 In FIG. 1, an infrared-visible conversion device having a structure in which the substrate 1 is a GaAs single crystal substrate whose plane orientation is the (111) direction and the phosphor layer 2 is a CaS phosphor layer to which Eu and Sm are added. Will be described.

[0025] The hitting the preparation of this element, first, placed in a vacuum deposition apparatus after cleaning the GaAs substrate 1, was evacuated to less than 10 ~ ⁶ Torr, H ₂ while heating the substrate 1 to 300 ° C. The substrate 1 was irradiated with S 2 gas while adjusting the flow rate to 10 sccm by a mass flow controller. At this time, the H ₂ S partial pressure at the substrate position was 2 × 10 to ⁵ Torr. In this state, substrate treatment was performed for 10 minutes, and then a CaS phosphor film 2 containing Eu and Sm was formed on the GaAs substrate 1 to a thickness of 20 μm.
In this case, the phosphor film 2 is formed by europium oxide (Eu ₂
O ₃ ) was added at 500 ppm and samarium oxide (Sm ₂ O ₃ ) was added at 150 ppm.
The electron beam evaporation method was carried out using CaS pellets as the evaporation source. At this time, the substrate temperature was 300 ° C. and the thin film formation rate was 50 nm / min.

The CaS phosphor film 2 formed as described above was inspected using a reflection electron beam diffractometer, an X-ray diffractometer and a transmission electron microscope. As a result, the polycrystal and the substrate 1 preferentially oriented in the (111) direction were obtained. It was confirmed that it was a mixed film with a single crystal epitaxially grown. Here, the preferential orientation means a state in which the crystallite size having a specific orientation is larger than the crystallite size having another orientation. In addition,
When the surface roughness of the film was measured using a stylus type surface roughness meter, it was confirmed that the unevenness of the surface was 10 nm or less, and an extremely smooth surface was obtained.

Table 2 compares the infrared-visible conversion efficiency and resolution of the infrared-visible conversion element prepared as described above and the infrared-visible conversion element prepared by forming the phosphor layer on the glass substrate. The result is shown. From this result, it is understood that the infrared-visible conversion element having the configuration of the present invention has higher infrared-visible conversion efficiency and higher resolution than the infrared-visible conversion element having the conventional structure. Further, since the device of the present invention uses the GaAs substrate and noise due to visible light is not superimposed, an image with extremely high contrast was obtained.

[0028]

[Table 2]

[0029]

Example 3 In FIG. 1, an infrared-visible conversion device having a structure in which the substrate 1 is a GaAs single crystal substrate having a plane orientation of (100) direction and the phosphor layer 2 is a CaS phosphor layer to which Eu and Sm are added. Will be described.

In the fabrication of this element, first, the GaAs substrate 1 is washed with pure water, acid, etc., then placed in a vacuum vapor deposition apparatus, and the substrate 1 is evacuated to 10 to ⁶ Torr or less, and the substrate 1 is heated to 300 ° C. The substrate was irradiated with H ₂ S gas while being heated to 10 nm while adjusting the flow rate to 10 sccm by a mass flow controller. At this time,
The H ₂ S partial pressure at the substrate position was 2 × 10 to ⁵ Torr. In this state, after the substrate surface treatment for 10 minutes, Eu on the substrate 1
A CaS phosphor film 2 containing Sm and Sm was formed to a thickness of 20 μm. Here, the phosphor layer 2 is formed by adding 5% of Eu ₂ O ₃ .
The electron beam evaporation method was carried out by using CaS pellets added with 00 ppm and Sm ₂ O ₃ of 150 ppm as an evaporation source. The thin film formation rate was 500 nm / min.

The CaS phosphor film 2 formed as described above was inspected by using a reflection electron beam diffractometer, an X-ray diffractometer and a transmission electron microscope, and it was found that it was a single crystal film epitaxially grown on the substrate. Was confirmed. Further, the surface roughness was measured using a stylus type surface roughness meter, and it was confirmed that the surface roughness was 10 nm or less, and the film was extremely smooth.

Table 3 shows the infrared-visible conversion efficiency and the resolution of the infrared-visible conversion element prepared as described above and the infrared-visible conversion element prepared by forming the phosphor layer on the glass substrate. The result of comparison is shown. From these results, it is understood that the infrared-visible conversion element of the present invention has higher infrared-visible conversion efficiency and higher resolution than the infrared-visible conversion element having the conventional structure. Further, since the device of the present invention uses the GaAs substrate and noise due to visible light is not superimposed, an image with extremely high contrast was obtained.

[0033]

[Table 3]

[0034]

Example 4 In FIG. 1, an infrared-visible conversion device having a structure in which the substrate 1 is a GaAs single crystal substrate having a (111) plane orientation and the phosphor layer 2 is an SrS phosphor layer containing Eu and Sm. Will be described.

In the fabrication of this element, first, the GaAs substrate 1 was washed with pure water and an acid, then placed in a molecular beam epitaxial apparatus and evacuated to 10 to ⁸ Torr or less, and the substrate 30
The substrate was irradiated with H ₂ S gas while being heated to 0 ° C. while adjusting the flow rate to 10 sccm by a mass flow controller. At this time, the H ₂ S partial pressure at the substrate position was 7 × 10 to ⁶ Torr. After the substrate surface treatment was performed for 10 minutes in this state, the substrate temperature was raised to 500 ° C. and the SrS phosphor layer 2 containing Eu and Sm was formed on the substrate 1 to a thickness of 10 μm. Here, the phosphor layer 2 is formed such that the Eu concentration is 500 ppm and the Sm concentration is 150 ppm.
Sr metal, Eu, filled in separate evaporation sources so that
The metal and the Sm metal were individually adjusted and evaporated by heating, and deposited on the substrate 1, and at the same time, the substrate 1 was irradiated with H ₂ S gas. The thin film formation rate at this time is
It was set to 50 nm / min.

The SrS phosphor layer 2 formed as described above was inspected by using a reflection electron beam diffractometer, an X-ray diffractometer and a transmission electron microscope, and as a result, it was confirmed that it was a single crystal film epitaxially grown on the substrate 1. Was done. Further, when the surface roughness was measured using a stylus type surface roughness meter, it was confirmed that the surface roughness was 10 nm or less and that the film was an extremely smooth film.

Table 4 shows the infrared-visible conversion efficiency and resolution of the infrared-visible conversion element prepared as described above and the infrared-visible conversion element prepared by forming the phosphor layer on the glass substrate. It is the table shown in comparison. From this result, it is understood that the infrared-visible conversion element of the present invention has higher infrared-visible conversion efficiency and higher resolution than the infrared-visible conversion element having the conventional configuration. Further, since the device of the present invention uses the GaAs substrate and noise due to visible light is not superimposed, an image with extremely high contrast was obtained.

[0038]

[Table 4]

[0039]

Fifth Embodiment In FIG. 1, an infrared-visible conversion device having a structure in which the substrate 1 is a GaAs single crystal substrate whose plane orientation is the (111) direction and the phosphor layer 2 is a CaSe phosphor layer to which Eu and Sm are added. Will be described.

In the fabrication of this element, first, the GaAs substrate 1 was washed with pure water and an acid, then placed in a molecular beam epitaxial apparatus and evacuated to 10 to ⁸ Torr or less, and the substrate was set to 30
The substrate was irradiated with H ₂ S gas while being heated to 0 ° C. while adjusting the flow rate to 10 sccm by a mass flow controller. At this time, the H ₂ S partial pressure at the substrate position was 7 × 10 to ⁶ Torr. After the substrate surface treatment was performed for 10 minutes in this state, the substrate temperature was raised to 500 ° C., and the CaSe phosphor layer 2 containing Eu and Sm was formed on the substrate 1 to a thickness of 20 μm. Here, the phosphor layer 2 is formed such that the Eu concentration is 300 ppm and the Sm concentration is 150 p.
Ca metal, Eu, filled in different evaporation sources so that
It was performed by adjusting the metal and the Sm metal, heating and evaporating them, depositing them on the substrate 1, and irradiating the substrate 1 with H ₂ Se gas at the same time. Also, the substrate temperature at this time is 500
The temperature and the thin film formation rate were 50 nm / min.

The CaSe phosphor layer 2 formed as described above was inspected by using a reflection electron diffraction apparatus, an X-ray diffraction apparatus and a transmission electron microscope, and as a result, it was confirmed that it was a single crystal film epitaxially grown on the substrate 1. Was done. Further, when the surface roughness was measured using a stylus type surface roughness meter, it was confirmed that the surface roughness was 10 nm or less and that the film was an extremely smooth film.

Table 5 shows the infrared-visible conversion efficiency and resolution of the infrared-visible conversion element prepared as described above and the infrared-visible conversion element prepared by forming the phosphor layer on the glass substrate. It is the table shown in comparison. From this result, it is understood that the infrared-visible conversion element of the present invention has higher infrared-visible conversion efficiency and higher resolution than the infrared-visible conversion element having the conventional configuration. Further, since the device of the present invention uses the GaAs substrate and noise due to visible light is not superimposed, an image with extremely high contrast was obtained.

[0043]

[Table 5]

[0044]

[Embodiment 6] An infrared-visible conversion device having a structure in which the substrate 1 in FIG. 1 is a GaAs single crystal substrate whose plane orientation is the (111) direction, and the phosphor layer 2 is an SrSe phosphor layer to which Eu and Sm are added. Will be described.

In the fabrication of this element, first, the GaAs substrate 1 was washed with pure water and an acid, then placed in a molecular beam epitaxial apparatus, and the substrate was evacuated to 10 to ⁸ Torr or less.
The substrate was irradiated with H ₂ Se gas while being heated to 0 ° C. while adjusting the flow rate to 10 sccm by a mass flow controller.
At this time, the H ₂ Se partial pressure at the substrate position was 7 × 10 to ⁶ Torr. After the substrate surface treatment was performed for 10 minutes in this state, the substrate temperature was raised to 500 ° C. and the SrSe phosphor layer 2 to which Eu and Sm were added was formed on the substrate 1 to a thickness of 10 μm. here,
The phosphor layer 2 is formed such that the Eu concentration is 500 ppm and the Sm concentration is 150 ppm.
Sr metal, E, charged in separate evaporation sources to ppm
u metal and Sm metal were adjusted and evaporated by heating, respectively, and deposited on the substrate 1, and at the same time, the substrate 1 was irradiated with H ₂ Se gas. The thin film formation rate at this time was 50 nm / min.

The SrSe phosphor layer 2 formed as described above was inspected using a reflection electron beam diffractometer, an X-ray diffractometer and a transmission electron microscope, and as a result, it was confirmed that it was a single crystal film epitaxially grown on the substrate 1. Was done. In addition, when the surface roughness was measured using a stylus type surface roughness meter, it was confirmed that the unevenness on the surface was 10 nm or less and was an extremely smooth film.

Table 6 shows the infrared-visible conversion efficiency and resolution of the infrared-visible conversion element prepared as described above and the infrared-visible conversion element prepared by forming the phosphor layer on the glass substrate. It is the table shown in comparison. From this result, it is understood that the infrared-visible conversion element of the present invention has higher infrared-visible conversion efficiency and higher resolution than the infrared-visible conversion element having the conventional configuration. Further, since the device of the present invention uses the GaAs substrate and noise due to visible light is not superimposed, an image with extremely high contrast was obtained.

[0048]

[Table 6]

In the above examples, CaS, SrS, CaSe or SrSe to which both Eu and Sm have been added are used as the phosphor layer, and the electron beam evaporation method and the molecular beam epitaxial method are used as the phosphor layer forming method. Used,
In addition, as the element structure, only the phosphor layer is provided on the substrate 2
The layer structure was explained, but as the phosphor matrix, C
A mixed crystal of aS, SrS, CaSe, and SrSe is used, and Ce is used as an additive.
And Sm, a sputtering method as a phosphor layer forming method,
Even when various thin film forming methods such as the MOCVD method and the CVD method were used, an infrared-visible conversion element having high resolution and high infrared-visible conversion efficiency could be realized. In addition, an infrared-visible conversion element with high resolution and infrared-visible conversion efficiency can be realized even with a multilayer structure element formed by further adding a layer for the purpose of antireflection or a layer for the purpose of protecting the phosphor as the element structure. We were able to.

[0050]

As described above, the infrared-visible conversion element is the infrared-visible conversion element of the present invention, that is, GaAs is used as the substrate, and Eu and Sm are used as the phosphor matrix in the phosphor. Is an infrared stimulable phosphor to which two kinds of Ce or Sm are added, and the phosphor matrix is CaS, Sr.
By using any one of S, CaSe, and SrSe, or an infrared-visible conversion element that uses an infrared stimulable phosphor that is a mixed crystal thereof, the problems that the conventional technology has are solved. As a result, an infrared-visible conversion element having high infrared-visible conversion efficiency and high resolution could be provided.

Further, the manufacturing method of the infrared-visible conversion element is the manufacturing method of the present invention, that is, the gas partial pressure at the substrate position is 1 × 10 ⁸ to ⁸ To while heating the substrate to 300 ° C. or higher.
By introducing H ₂ S gas or H ₂ Se gas to the surface of the substrate so as to obtain rr and then forming the infrared stimulable phosphor layer, the infrared-visible conversion efficiency is high. In addition, it was possible to provide a manufacturing method capable of obtaining an infrared-visible conversion element having high resolution.

[Brief description of drawings]

FIG. 1 is a sectional view showing a basic configuration of an infrared-visible conversion element of the present invention.

[Fig.2] Substrate GaAs lattice constant and phosphor matrix CaS, Sr
The figure which shows the relationship of lattice constant with S, CaSe, and SrSe.

FIG. 3 (a) shows the relationship between the substrate temperature and the half width of the X-ray rocking curve during the surface treatment of the substrate with H ₂ S, and FIG. 3 (b) shows H ₂ Se.
The figure which shows the relationship between the substrate temperature and the X-ray rocking curve half value width at the time of substrate surface treatment by.

[Fig. 4] (a) shows the H ₂ S partial pressure and the X of the produced CaS film when the substrate temperature is 300 ° C and the H ₂ S partial pressure is changed to form the CaS film.
The relationship between the line rocking curve half width, (b) is a substrate temperature of 300 ° C., X-ray rocking curve of the H ₂ Se partial pressure generating CaSe film in the case of forming the CaSe film by changing the H ₂ Se partial pressure The figure which shows the relationship with a half value width.

[Explanation of symbols]

 1 ... GaAs substrate, 2 ... Infrared stimulated phosphor layer.

Claims (2)

[Claims] 1. An infrared-visible conversion device comprising an gallium arsenide substrate on which an infrared stimulable phosphor layer is formed, wherein the infrared stimulable phosphor has at least two types of phosphor matrix, europium and samarium. Alternatively, it is an infrared stimulable phosphor to which at least two kinds of cerium and samarium are added, and the phosphor matrix is any one of calcium sulfide, strontium sulfide, calcium selenide, and strontium selenide. Alternatively, an infrared-visible conversion element characterized by being a mixed crystal thereof. 2. In the manufacture of an infrared-visible conversion element comprising an infrared stimulable phosphor layer formed on a gallium arsenide substrate, the gas partial pressure at the substrate position is 1 while heating the substrate to 300 ° C. or higher. An infrared-visible conversion characterized by forming an infrared stimulable phosphor layer after surface treatment of the substrate by introducing hydrogen sulfide gas or hydrogen selenide gas to a value of × 10 to ⁸ Torr or more. Manufacturing method of device.