JP2009117239A - Inorganic electroluminescent element, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inorganic EL element which improves luminance by irradiating a laser on a light emitting layer containing sulfur, capable of further improving the luminance by laser irradiation. <P>SOLUTION: In the manufacturing method of the inorganic EL element, a lower electrode 12, a lower insulating layer 13, a light emitting layer 14 formed of SrS:Cu and Ag as a light emitting layer containing the sulfur, an upper insulating layer 16, and an upper electrode 17 are sequentially formed on a glass substrate 11. The manufacturing method includes a process for forming a cap layer 15 formed by adding the sulfur to the insulating layer mainly containing silicon oxide as a layer containing the sulfur on the light emitting layer 14 after forming the light emitting layer 14, a process for irradiating the laser on the light emitting layer 14 through the cap layer 15 from above the cap layer 15, and a process for subsequently forming the upper insulating layer 16 on the cap layer 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inorganic electroluminescent device (hereinafter referred to as an inorganic EL device) used for, for example, a transparent display and a method for producing the same, and more particularly to a device for increasing luminance by irradiating a light emitting layer containing sulfur with a laser. .

  An inorganic EL element utilizes a phenomenon that emits light when an electric field is applied to a phosphor such as zinc sulfide (ZnS), and has attracted attention as a self-luminous flat display. In general, an inorganic EL element is formed by sequentially forming a lower electrode, a lower insulating layer, a light emitting layer, an upper insulating layer, and an upper electrode on an insulating substrate, and at least the light extraction side is formed of an optically transparent material. It becomes.

Here, conventionally, there has been proposed a method for realizing high luminance by irradiating a light emitting layer with a laser after forming the light emitting layer and annealing the light emitting layer with heat generated at that time (for example, Patent Document 1).
JP 2006-32289 A

  However, according to the study by the present inventor, in the conventional laser annealing method, since the laser is directly irradiated from the light emitting layer, when the light emitting layer contains sulfur (S), sulfur is released by the laser irradiation and the light emitting layer is exposed. It was found that the composition of was shifted. As a result, the effect of increasing the brightness by laser annealing is reduced.

  The present invention has been made in view of the above problems, and in an inorganic EL element in which a light emitting layer containing sulfur is irradiated with a laser to increase the brightness, further enhancement of the brightness by laser irradiation is realized. With the goal.

  In order to achieve the above object, the present invention provides a lower electrode (12), a lower insulating layer (13), a light emitting layer (14) containing sulfur (S), and an upper insulating layer (16) on an insulating substrate (11). ), In the method of manufacturing an inorganic EL element in which the upper electrode (17) is sequentially formed, after forming the light emitting layer (14), a cap layer (15) which is a layer containing sulfur (S) is formed on the light emitting layer (14). ), A step of irradiating the light emitting layer (14) with a laser from above the cap layer (15) through the cap layer (15), and then an upper insulating layer (on the cap layer (15)). 16) is a first feature.

  The present invention has been found experimentally, and by performing laser irradiation in a state where the light emitting layer (14) is covered with a cap layer (15) containing sulfur, the sulfur of the light emitting layer (14) can be obtained. By suppressing the omission, as shown in FIG. 3 to be described later, it is possible to realize further higher luminance by laser irradiation as compared with the conventional case.

  In addition, in the above conventional laser annealing method, high energy laser irradiation is necessary for high brightness, but when the laser is irradiated with high energy, the light emitting layer is ablated, and the luminance improvement effect is small. Problems such as narrow windows are likely to occur. However, according to the present manufacturing method, the cap layer (15) plays a role of blocking heat radiation from the light emitting layer (14) during laser irradiation, so that the laser irradiation energy is less than the irradiation energy that the light emitting layer ablates efficiently. The light emitting layer (14) can be annealed.

  Here, in the step of forming the cap layer (15), a layer is formed on the light emitting layer (14) with a material excluding sulfur among the materials constituting the cap layer (15), and then the layer is heated to 200 ° C. or higher. If the heat treatment is performed to diffuse sulfur from the light emitting layer (14) to the layer, the cap layer (15) can be appropriately formed.

The cap layer (15) can be formed by adding sulfur to an insulating layer mainly composed of silicon oxide (SiO ₂ ).

  The light emitting layer (14) is preferably formed as a light emitting layer containing strontium sulfide (SrS) as a main component, and in the laser irradiation step, it is preferable to perform laser irradiation using an excimer laser of 308 nm.

  Further, according to the present invention, in the inorganic EL element, a cap layer (15) that is a layer containing sulfur (S) is interposed between the light emitting layer (14) and the upper insulating layer (16). The second feature.

  The inorganic EL element of the present invention is appropriately manufactured by the manufacturing method having the first feature, and in this case as well, as shown in FIG. High brightness can be realized.

Also in this inorganic EL element, the light emitting layer (14) can be a light emitting layer mainly composed of strontium sulfide (SrS), and the cap layer (15) is composed mainly of silicon oxide (SiO ₂ ). It can be made by adding sulfur to the insulating layer.

  In addition, the code | symbol in the bracket | parenthesis of each means described in the claim and this column is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, parts that are the same or equivalent to each other are given the same reference numerals in the drawings for the sake of simplicity.

  In this embodiment, after forming the light emitting layer and before forming the upper insulating layer, the light emitting layer is irradiated with a laser to perform heat treatment, thereby improving the crystallinity of the light emitting layer and increasing the luminance of the inorganic EL element. It is something that is going to be raised.

  FIG. 1 is a diagram showing a schematic cross-sectional configuration of an inorganic EL element 100 according to this embodiment. The inorganic EL element 100 is configured by sequentially stacking the following thin films on a glass substrate 11 that is an insulating substrate.

  In the inorganic EL element 100 of the present embodiment, since the upper and lower layers of the light emitting layer 14 are all transparent, light from the light emitting layer 14 can be extracted from both sides of the insulating substrate 11 and the upper electrode 17.

  The glass substrate 11 is a transparent electrically insulating substrate such as soda glass. An optically transparent lower electrode 12 is formed on the glass substrate 11. The lower electrode 12 of the present embodiment is made of an ITO (indium tin oxide) film.

On the lower electrode 12, a lower insulating layer 13 that is optically transparent and electrically insulating is formed. In the present embodiment, the lower insulating layer 13 is made of an Al ₂ O ₃ / TiO ₂ laminated structure film in which Al ₂ O ₃ and TiO ₂ are alternately laminated, and has a thickness of about 400 nm. Here, Al ₂ O ₃ is alumina and TiO ₂ is titania.

  A light emitting layer 14 containing sulfur (S) is formed on the lower insulating layer 13. The light emitting layer 14 of the present embodiment is SrS: Cu, Ag using SrS (strontium sulfide) as a base material and Cu (copper) and Ag (silver) added as the emission center. The thickness of the light emitting layer 14 is about 1.5 μm.

In this embodiment, a cap layer 15 that is a layer containing sulfur (S) is formed on the light emitting layer 14. The cap layer 15 is composed of silicon oxide (SiO ₂ ), which is an inorganic insulating material, as a main component, that is, a base material, to which sulfur is added. The cap layer 15 has a function of suppressing sulfur escape from the light emitting layer 14 in a laser irradiation process to be described later.

  Here, the sulfur concentration in the cap layer 15 is desirably 1 mol% or more and 20 mol% or less. This is based on the result of the experiment by the present inventor. If the sulfur concentration is 1 mol% or more, the above-described sulfur desorption suppression function is appropriately exhibited. Further, when the amount exceeds 20 mol%, the details are unknown, but it has been experimentally confirmed that the luminance of the inorganic EL element 100 decreases.

  It is desirable that the cap layer be as thin as possible. As is well known, the drive voltage of the inorganic EL element is determined by the thickness of the light emitting layer 14 and the capacitance of the insulating layers (the lower insulating layer 13 and the upper insulating layer 16). Here, since the cap layer 15 is an insulating layer, the capacity is reduced by the thickness of the inserted cap layer, and as a result, the drive voltage of the inorganic EL element is increased.

  In the case of this embodiment, since the cap layer 15 mainly composed of silicon oxide (SiO 2) corresponding to the film thickness of 400 nm of the upper insulating layer 16 that is the Al 2 O 3 / TiO 2 laminated structure film is 90 nm, the cap layer 15 The film thickness is preferably smaller than 90 nm. However, if the film thickness of the cap layer 15 is 90 nm, the film thickness of the upper insulating layer 16 becomes zero due to the limitation of the driving voltage, and the reliability of the inorganic EL element is lowered. In order to ensure the reliability of the inorganic EL element, the thickness is preferably 50 nm or less.

  Moreover, according to examination of this inventor, in order for the said sulfur desorption suppression function to be exhibited appropriately, it is desirable that the film thickness of the cap layer 15 is 5 nm or more. If the knowledge regarding the sulfur concentration and film thickness in these cap layers 15 is put together, in this embodiment, it is preferred that cap layer 15 shall be 1-20 mol% of sulfur concentration, and a film thickness shall be 5-50 nm.

On the cap layer 15, an optically transparent and electrically insulating upper insulating layer 16 is formed. In the present embodiment, the upper insulating layer 16 is made of an Al ₂ O ₃ / TiO ₂ laminated structure film having a thickness of about 400 nm, like the lower insulating layer 13.

  An optically transparent upper electrode 17 is formed on the upper insulating layer 16. The upper electrode 17 of the present embodiment is made of an ITO film like the lower electrode 12. In FIG. 1, the lower electrode 12 extends in the left-right direction in FIG. 1 but has a stripe shape in which a plurality of lower electrodes 12 are arranged in the direction perpendicular to the paper surface. The upper electrode 17 is orthogonal to the lower electrode 12. Form a stripe.

  In the inorganic EL element 100 of the present embodiment, a portion sandwiched between the upper and lower electrodes 12 and 17 is configured as a pixel, and the light emitting layer 14 emits light by applying a voltage to the upper and lower electrodes 12 and 17. The light is extracted from the insulating substrate 11 side and the upper electrode 17.

Next, a method for manufacturing the inorganic EL element 100 will be described. First, an ITO film is formed as a lower electrode 12 on the glass substrate 1 by a sputtering method and patterned by a photolithographic technique. On top of this, an Al ₂ O ₃ / TiO ₂ laminated structure film as the lower insulating layer 13 is formed by an ALD (Atomic-Layer-Deposition) method.

Specifically, an Al ₂ O ₃ / TiO ₂ laminated structure film is formed as follows. First, as the first step, aluminum trichloride (AlCl ₃ ) is used as the source gas for aluminum (Al), and water (H ₂ O) is used as the source gas for oxygen (O), and the Al ₂ O ₃ layer is subjected to the ALD method. Form with.

In the ALD method, source gases are alternately supplied in order to form a film by one atomic layer. Therefore, in this case, AlCl ₃ is introduced into the reaction furnace with argon (Ar) carrier gas for 1 second, and then a purge sufficient to exhaust the AlCl ₃ gas in the reaction furnace is performed. Next, H ₂ O is similarly introduced into the reaction furnace with Ar carrier gas for 1 second, and then a purge sufficient to exhaust the H ₂ O in the reaction furnace is performed. This cycle is repeated to form an Al ₂ O ₃ layer having a predetermined thickness.

As a second step, a titanium oxide layer is formed using titanium tetrachloride (TiCl ₄ ) as the Ti source gas and H ₂ O as the oxygen source gas. Specifically, TiCl ₄ is introduced into the reaction furnace with Ar carrier gas for 1 second as in the first step, and then a purge sufficient to exhaust TiCl ₄ in the reaction furnace is performed. Next, H ₂ O is similarly introduced into the reaction furnace with Ar carrier gas for 1 second, and then a purge sufficient to exhaust the H ₂ O in the reaction furnace is performed. This cycle is repeated to form a titanium oxide layer having a predetermined thickness.

Then, the first step and the second step described above are repeated to form an Al ₂ O ₃ / TiO ₂ laminated structure film having a predetermined thickness, and this is used as the lower insulating layer 13. Specifically, both the Al ₂ O ₃ layer and the TiO ₂ layer have a thickness of 5 nm per layer, and a structure in which 40 layers are laminated to a thickness of 400 nm. The first and last layers of the Al ₂ O ₃ / TiO ₂ laminated structure film may be either an Al ₂ O ₃ layer or a TiO ₂ layer.

  In addition, when a film is formed on the atomic layer order using the ALD method, a film thinner than 0.5 nm does not function as an insulator, and when the film thickness per layer is larger than 20 nm, it depends on the laminated structure. The effect of improving the withstand voltage is reduced. Therefore, the film thickness per layer of the multilayer structure film is 0.5 nm to 20 nm, preferably 1 nm to 10 nm.

Then, a light emitting layer 14 made of SrS: Cu, Ag is formed on the lower insulating layer 13 by sputtering. That is, 0.1 to 2.0% by weight of Cu ₂ S powder and 0.1 to 2.0% by weight of Ag ₂ S powder are mixed in SrS powder and molded into a predetermined shape, and then 800 to 1000%. The target is formed by RF magnetron sputtering using a target formed by sintering at a temperature of about ° C.

Specifically, the glass substrate 11 is set in a vacuum chamber so as to face the target, and heating is performed so that the temperature of the glass substrate is 150 to 300 ° C., more preferably 200 to 250 ° C. After heating the glass substrate 11 to a predetermined temperature, Ar gas is introduced into the vacuum chamber, and the gas flow rate and the like are adjusted so that the pressure in the vacuum chamber is about 1 × 10 ^{−3 to} 3 × 10 ⁻³ Torr. .

  Thereafter, high frequency power is applied to the target and sputtering is performed. At this time, the input power to the target and the sputtering time are adjusted so that the thickness of the light emitting layer 14 is about 1.5 μm. Thus, the light emitting layer 14 is formed.

  Next, the cap layer 15 containing sulfur is formed on the light emitting layer 14 (cap layer forming step). In this cap layer forming step, first, a layer is formed on the light emitting layer 14 by a material excluding sulfur among materials constituting the cap layer 15. In the present embodiment, the material excluding sulfur is silicon oxide, and the layer is formed by sputtering to a thickness of 1 to 20 nm.

  Next, the silicon oxide layer is heat-treated at 200 ° C. or higher by an oven or the like to diffuse sulfur from the light emitting layer 14 to the silicon oxide layer. The atmosphere for this heat treatment can be performed in a vacuum, in an inert gas, or in the air. Thereby, the cap layer 15 of this embodiment is completed as a layer of silicon oxide containing sulfur.

  Here, the reason why the heat treatment temperature is set to 200 ° C. or more is based on the experiment by the inventors. It has been confirmed that the diffusion of sulfur from the light emitting layer 14 to the silicon oxide layer hardly occurs in the heat treatment at room temperature to less than 200 ° C.

  Further, this heat treatment needs to be performed at a temperature below the strain point of the glass substrate 11 which is an insulating substrate. For example, when soda glass having a strain point of about 500 ° C. is used, the heat treatment is performed at 200 ° C. or more and 500 ° C. or less.

  Next, a step of irradiating the light emitting layer 14 with a laser from above the cap layer 15 through the cap layer 15 (laser irradiation step). FIG. 2 is a process diagram showing a laser irradiation process in the manufacturing method of the present embodiment.

  Here, since the light emitting layer 14 is a light emitting layer containing strontium sulfide (SrS) as a main component, laser irradiation is performed using an excimer laser of 308 nm. In the case of a light emitting layer containing strontium sulfide (SrS) as a main component, if the wavelength of the laser to be used is increased, the absorptance in the light emitting layer is reduced and the effect of laser annealing is reduced. Moreover, when the wavelength of the laser to be used is shortened, it is absorbed only on the surface of the light emitting layer. Of the existing lasers, a 308 nm excimer laser is optimal.

  As shown in FIG. 2, the laser irradiated from the direction of the arrow L passes through the cap layer 15 and hits the light emitting layer 14. Thus, high luminance is realized by irradiating the light emitting layer 14 with a laser and annealing the light emitting layer 14 with heat generated at that time.

  Thereafter, the upper insulating layer 16 is formed with the same structure and film thickness as the lower insulating layer 13 by the ALD method, and finally the ITO film is formed as the upper electrode 17 in the same manner as the lower electrode 12. Thereby, the inorganic EL element 100 as shown in FIG. 1 is completed.

  That is, according to the present embodiment, the lower electrode 12, the lower insulating layer 13, the sulfur-containing light emitting layer 14, the upper insulating layer 16, and the upper electrode 17 are sequentially formed on the insulating substrate 11, and at least the light extraction side is formed. In the inorganic EL element 100 formed of an optically transparent material, the inorganic EL element 100 in which a cap layer 15 that is a layer containing sulfur is interposed between the light emitting layer 14 and the upper insulating layer 16. Provided.

  In the manufacturing method for manufacturing the inorganic EL element 100, the cap layer forming process and the laser irradiation process are performed after forming the light emitting layer 14, and then the upper insulating layer 16 is formed on the cap layer 15. is there.

  Thus, in the present manufacturing method, as described above, when the light emitting layer containing sulfur is irradiated with the laser, attention is paid to the effect of increasing the brightness due to the generation of sulfur loss, and the cap layer 15 In this state, a unique method of performing laser irradiation in a state in which is newly provided on the light emitting layer 14 is employed.

  FIG. 3 is a diagram specifically showing the effect of increasing the brightness by laser irradiation in the present manufacturing method, and a comparison corresponding to the inorganic EL element 100 manufactured by the manufacturing method of the present embodiment and the inorganic EL element having the conventional structure. It is a figure which shows the result of having investigated EL light emission luminance by the example.

  Here, in the inorganic EL element 100 of the present embodiment, the light emitting layer 14 is made of SrS: Cu, Ag and has a film thickness of 1.5 μm, and the cap layer 15 has 8 mol% of sulfur using silicon oxide as a base material. The added film thickness is 20 nm. The cap layer 15 was produced by heat-treating a silicon oxide layer formed by sputtering at 300 ° C. in an air atmosphere.

  The comparative example is an inorganic EL element in which the cap layer 15 is omitted in the configuration shown in FIG. Laser irradiation was performed under the same conditions with an excimer laser of 308 nm in both this embodiment and the comparative example. The EL light emission luminance is a luminance when a pulse wave of 240 Hz and 20 μsec is driven with the same voltage in both the present embodiment and the comparative example. In FIG. 3, the luminance level of the comparative example is normalized to 1.

  As shown in FIG. 3, the inorganic EL element 100 according to the present embodiment achieves higher luminance by laser irradiation than the comparative example corresponding to the conventional configuration. And the effect of this embodiment is based on suppressing the escape of sulfur in the light emitting layer 14 by performing laser irradiation in a state where the light emitting layer 14 is covered with the cap layer 15 containing sulfur.

  With respect to this mechanism, conventionally, sulfur in the light emitting layer escapes out of the light emitting layer by laser irradiation of the light emitting layer containing sulfur, whereas in this embodiment, the cap layer that covers the light emitting layer 14 is used. Since 15 contains sulfur, it is difficult for sulfur in the light emitting layer 14 to diffuse into the cap layer 15, and therefore, it is considered that the escape of sulfur is suppressed.

  This mechanism was actually confirmed by investigating the composition of sulfur in the light emitting layer before and after laser irradiation by SIMS analysis (secondary ion mass spectrometry) in this embodiment and the comparative example in FIG. . That is, in this embodiment and the comparative example, the concentration distribution of sulfur in the film thickness direction in the light emitting layer 14 before laser irradiation was constant throughout the light emitting layer regardless of the distance in the film thickness direction.

  In the present embodiment, even after the laser irradiation, the concentration distribution of sulfur in the film thickness direction in the light emitting layer 14 is hardly changed from that before the laser irradiation, and there is substantially no loss of sulfur. It was confirmed that there was no change in the composition.

  On the other hand, in the comparative example, the concentration distribution of sulfur in the film thickness direction in the light emitting layer 14 after laser irradiation increases from the deepest part of the light emitting layer (near the interface with the lower insulating layer) to the part on the surface layer side. It was confirmed that the sulfur concentration was reduced to such an extent that almost no sulfur was confirmed on the surface layer. That is, in the comparative example, it was confirmed that sulfur loss occurred and the composition change of the light emitting layer 14 occurred.

  As described above, according to the manufacturing method and the inorganic EL element 100 of the present embodiment, the laser irradiation can be performed in a state where the light emitting layer 14 is covered with the cap layer 15 containing sulfur. In order to suppress the omission, it is possible to realize further higher brightness by laser irradiation compared to the conventional case.

  In addition, in the above conventional laser annealing method, high energy laser irradiation is necessary for high brightness, but when the laser is irradiated with high energy, the light emitting layer is ablated, and the luminance improvement effect is small. Problems such as narrow windows are likely to occur.

  However, according to the manufacturing method of the present embodiment described above, since the cap layer 15 plays a role of blocking heat radiation from the light emitting layer 14 during laser irradiation, the laser irradiation energy is less than the irradiation energy ablated by the light emitting layer. The light emitting layer 14 can be annealed well.

(Other embodiments)
In the manufacturing method of the above embodiment, after forming a layer with a material excluding sulfur among the materials constituting the cap layer 15, the layer is heat-treated at 200 ° C. or more to diffuse sulfur from the light emitting layer 14 to the layer. Thus, the cap layer 15 is formed, but the method of forming the cap layer 15 is not limited to this.

  For example, when the cap layer 15 is formed by adding sulfur to an insulating layer containing silicon oxide as a main component, the cap layer 15 can be manufactured by doping sulfur into the cap layer 15 by ion implantation.

The insulating substrate 11 may be a substrate made of resin or the like in addition to the glass substrate 11 as long as it is a transparent electrically insulating substrate. The lower and upper electrodes 12 and 17 may be other than the ITO film as long as it is an optically transparent conductive film. The lower and upper insulating layers 13 and 16 may be, for example, an alumina-only film or a silica film in addition to the Al ₂ O ₃ / TiO ₂ laminated structure film.

  Moreover, as the light emitting layer 14, the light emitting material in general inorganic EL can be employ | adopted if it contains sulfur. In addition to the above SrS: Cu, Ag, ZnS (zinc sulfide) is used as a base material, ZnS: Mn to which Mn (manganese) is added as an emission center, and CaS (calcium sulfide) is used as a base material, and Eu ( And CaS: Eu to which europium) is added. These film forming methods are the same as general methods.

The cap layer 15 may be any layer containing sulfur (S). In addition to the above-described insulating layer containing silicon oxide (SiO ₂ ) as a main component, sulfur is added to the cap layer 15. The material may be a base material to which sulfur is added.

  Further, in the inorganic EL element 100 shown in FIG. 1, since the upper and lower layers of the light emitting layer 14 are all transparent, light from the light emitting layer 14 can be extracted from both sides of the insulating substrate 11 and the upper electrode 17. For example, the layer on the upper electrode 17 side with respect to the light emitting layer 14 may be an opaque layer and may extract light only on the insulating substrate 11 side. For example, the electrode opposite to the light extraction side may be a metal electrode that is not transparent, and light may be extracted from one side of the light emitting layer 14.

It is a schematic sectional drawing of the inorganic EL element which concerns on embodiment of this invention. It is process drawing which shows the laser irradiation process in the manufacturing method of the said embodiment. It is a figure which shows concretely the effect of high brightness by laser irradiation in the said embodiment.

Explanation of symbols

11 ... Glass substrate as insulating substrate, 12 ... Lower electrode, 13 ... Lower insulating layer,
14 ... light emitting layer, 15 ... cap layer, 16 ... upper insulating layer, 17 ... upper electrode.

Claims (7)

On the insulating substrate (11), a lower electrode (12), a lower insulating layer (13), a light emitting layer (14) containing sulfur (S), an upper insulating layer (16), and an upper electrode (17) are sequentially formed. In addition, in the method of manufacturing an inorganic electroluminescent element formed by forming an optically transparent material at least on the light extraction side,
Forming the cap layer (15), which is a layer containing sulfur (S), on the light emitting layer (14) after forming the light emitting layer (14);
Irradiating the light emitting layer (14) with a laser from above the cap layer (15) through the cap layer (15);
Then, the process of forming the said upper insulating layer (16) on the said cap layer (15), The manufacturing method of the inorganic electroluminescent element characterized by the above-mentioned. In the step of forming the cap layer (15), a layer is formed on the light emitting layer (14) with a material excluding sulfur among the materials constituting the cap layer (15), and then the layer is formed at 200 ° C. or higher. The method for manufacturing an inorganic electroluminescent element according to claim 1, wherein the cap layer (15) is formed by diffusing sulfur from the light emitting layer (14) to the layer by heat treatment. Said cap layer (15), method of producing an inorganic electroluminescent device according to claim 1 or 2, characterized in that formed as the addition of sulfur to the insulating layer mainly composed of silicon oxide (SiO ₂₎ . The light emitting layer (14) is formed as a light emitting layer mainly composed of strontium sulfide (SrS), and in the laser irradiation step, laser irradiation is performed using an excimer laser of 308 nm. The manufacturing method of the inorganic electroluminescent element as described in any one of thru | or 3. On the insulating substrate (11), a lower electrode (12), a lower insulating layer (13), a light emitting layer (14) containing sulfur (S), an upper insulating layer (16), and an upper electrode (17) are sequentially formed. In an inorganic electroluminescence device comprising at least the light extraction side made of an optically transparent material,
An inorganic electroluminescent element, wherein a cap layer (15), which is a layer containing sulfur (S), is interposed between the light emitting layer (14) and the upper insulating layer (16). 6. The inorganic electroluminescent device according to claim 5, wherein the light emitting layer (14) is a light emitting layer mainly composed of strontium sulfide (SrS). The inorganic electroluminescence device according to claim 5 or 6, wherein the cap layer (15) is obtained by adding sulfur to an insulating layer mainly composed of silicon oxide (SiO ₂ ).

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