JPH08225782A - Production of electroluminescent thin film - Google Patents

Abstract

PURPOSE: To obtain the subject film having a high emission luminance in a short time by forming the film containing a IIa-sulfur compound semiconductor as a matrix in sulfur gas atmosphere under a low pressure and then heat- treating the resultant film according to a specific method. CONSTITUTION: This method for forming an electroluminescent thin film comprises forming a thin film containing a IIa-sulfur compound semiconductor as a matrix in a gas atmosphere selected from sulfur, diethyl sulfide and dimethyl sulfide under a low pressure and subsequently heat-treating the resultant film in a gas atmosphere comprising an inert gas and any of the above gases under atmospheric pressure. In the case of the sulfur gas, the pressure in forming the film is preferably 8×10<-3> to 6.7×10<-2> Pa and the partial pressure for the inert gas in the heat treatment is preferably 2.7×10<4> to 8×10<4> Pa. In the case of the diethyl sulfide gas, the pressure in forming the film is 8×10<-4> to 8×10<-3> Pa and the partial pressure for the inert gas in the heat treatment is preferably 1.3×10<3> to 8×10<3> Pa. Furthermore, in the case of the dimethyl sulfide gas, the pressure in forming the film is preferably 6.7×10<-4> to 1.2×10<-2> Pa and the partial pressure for the inert gas. in the heat treatment is preferably 6.7×10<3> to 1.7×10<4> Pa.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent thin film containing a IIa-VIb group compound semiconductor as a base material.

[0002]

2. Description of the Related Art Electroluminescent (hereinafter abbreviated as EL) elements for displays have achieved high brightness and long life by applying a double insulating layer structure, and have been put to practical use as lightweight and thin display devices. . FIG. 13 is a cross-sectional view of a double insulating layer structure EL element. On the glass substrate 1, a transparent electrode layer 2, a first insulating layer 3, an EL light emitting layer 4,
The second insulating layer 5 and the back electrode layer 6 are sequentially stacked.

The transparent electrode layer 2 is, for example, a vapor-deposited or sputtered thin film of indium tin oxide (ITO). For the first insulating layer 3 and the second insulating layer 5, thin films of silicon dioxide, silicon nitride and other metal oxides are used. Usually, the insulating layers are symmetrically arranged with the EL light emitting layer 4 sandwiched therebetween, because they are driven and emitted by an AC voltage applied between the transparent electrode layer 2 and the back electrode layer 6. The second insulating layer 5 completely covers the side surface of the EL light emitting layer 4, and the conductive carrier in the EL light emitting layer 4 is not supplied from the outside to stabilize the luminance characteristic. Shut off from the outside air,
A long life is achieved because the EL element is prevented from being altered.

The back electrode layer 6 is a vapor-deposited or sputtered thin film of metal such as aluminum. Each electrode layer is often patterned according to the purpose of display. The EL light emitting layer 4 is composed of a IIa-VIb group compound semiconductor as a base material, and rare earth elements are often added as a light emission center. AC voltage is applied to the transparent electrode layer 2 and the back electrode layer 6 to increase the voltage, and when the electric field of the EL light emitting layer 4 reaches a light emission starting electric field of about 1.3 × 10 ⁶ V / cm, light emission starts, and a little more than that. The emission brightness is saturated in a high electric field. The conditions for the EL light emitting layer are that the light emission starting electric field is low and the brightness is high.

In the case where the base material is a IIa-VIb group compound semiconductor and the added luminescence center is a rare earth element. The EL emission mechanism is recombination emission of electrons ionized from the emission center hit by hot electrons excited by an electric field with holes. A typical example is ZnS: Ce. In order for the electric field excitation to be performed efficiently, it is necessary to obtain as high energy as possible from the electric field without causing hot electrons to collide with defects other than the emission center. This can be achieved by the fact that there are few defects other than the emission center and the conduction electron source in the host crystal.

The EL light emitting layer 4 has a thickness of about 0.5 μm IIa-
It is a VIb group compound semiconductor thin film, and there are several types of film formation methods.However, since it is easy to add impurities and form large areas, the electron beam evaporation method and the sputtering method are mainly used at the manufacturing level. is there. The VIb group element has a higher saturated vapor pressure than the IIa group element, and the VIb group element is easily dissociated. In each of the film forming methods, measures are taken to prevent dissociation of the VIb group element, but it is impossible to completely eliminate defects due to the VIb group element deficiency. The EL emission layer immediately after film formation is II
Not only defects due to stoichiometric difference between the group VI element and the group VI element (VIb group element is insufficient), but the amorphous layer and the fine particles generated from it due to the film formation on materials with different crystal types. It also has crystal grain boundaries. for that reason,
The light emission starting electric field is high and the light emission luminance is low. Since the amorphous layer does not emit EL light, it is called dead layer. In addition, the oxygen taken into the light emitting layer during the film formation by the above method acts as an electron trap and deteriorates the light emitting property.

In order to solve the problems of high emission starting electric field and low emission brightness after film formation, attempts have been made to improve the film formation method and heat treat the EL light emitting layer immediately after film formation to improve the crystallinity. ing. The heat treatment of the EL light emitting layer in a vacuum or in an inert gas atmosphere does not improve the crystallinity due to the generation of vacancies due to the dissociation of the Group VI element from the compound semiconductor base material. In order to prevent the dissociation of the VIb group element during the heat treatment, the heat treatment atmosphere and the treatment conditions are set to 700 ° C. in a sulfur gas or an inert gas containing sulfur gas or hydrogen sulfide, as proposed in JP-A 1-272093. Processing for 5 hours, or Japanese Patent Laid-Open No. 4
650 ° C. in sulfidizing gas as proposed by -121995
Attempts have been made to carry out the treatment at the above temperature for 4 hours. However, in the latter case, the EL emission layer to which an additive other than the emission center is added is targeted.

There is no known heat treatment for a thin film containing a Group IIa-selenium compound semiconductor as a base material in a low pressure selenium gas atmosphere or after the film formation in a selenium atmosphere.

[0009]

However, in such a heat treatment method, since the sulfur gas concentration is low not only when sulfur gas is not added but also when sulfur gas is added, the oxygen in the EL thin film is reduced. Are not sufficiently removed or the crystallinity is not improved. Further, the heat treatment time is long, and there is a possibility that the substrate may be deformed or the transparent electrode may be deteriorated.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a high emission luminance of a group IIa-sulfur compound semiconductor and a group IIa-.
An object of the present invention is to provide a method for manufacturing an EL thin film using a selenium compound semiconductor as a base material.

[0011]

In order to achieve the above object, the first invention is that a thin film containing a group IIa-sulfur compound semiconductor as a base material is selected from low-pressure sulfur, diethyl sulfide and dimethyl sulfide. A method for producing an electroluminescent thin film is one in which film formation is performed in any gas atmosphere, and then heat treatment is performed in a gas atmosphere of an inert gas at atmospheric pressure and one of the sulfurizing gases.

In the manufacturing method according to the first aspect of the invention, the pressure of the sulfur gas atmosphere during film formation is 8.0 × 10 ^{−3 to} 6.7 × 10 ^−2.
Pa and the partial pressure of sulfur against the inert gas during heat treatment
2.7 × 10 ^{4 to} 8.0 × 10 ⁴ Pa is preferable. In the manufacturing method according to the first aspect of the present invention, the pressure of the diethyl sulfide gas atmosphere during film formation is 8.0 × 10 ^-4 to 8.0 × 10 ^-3 Pa, and the partial pressure of diethyl sulfide with respect to the inert gas during the heat treatment is 1.3. ×
It is good to set it to 10 ^{3 to} 8.0 × 10 ³ Pa.

In the manufacturing method according to the first invention, the pressure of the dimethyl sulfide gas atmosphere during film formation is 6.7 × 10 ^-4 to 1.
It is preferable that the pressure is 2 × 10 ⁻² Pa and the partial pressure of dimethyl sulfide with respect to the inert gas during the heat treatment is 6.7 × 10 ^{3 to} 1.7 × 10 ⁴ Pa. A second invention is an electroluminescent thin film in which a thin film containing a Group IIa-selenium compound semiconductor as a base material is formed in a low-pressure selenium gas atmosphere and then heat-treated in a mixed gas atmosphere of an inert gas and selenium gas under normal pressure. The manufacturing method of

In the manufacturing method according to the second aspect of the invention, the pressure of the selenium gas atmosphere during film formation is 9.3 × 10 ^{−3 to} 6.7 × 10.
^{It is} preferable that the pressure is ⁻² Pa and the partial pressure of selenium with respect to the inert gas during the heat treatment is 6.7 × 10 ^{3 to} 3.3 × 10 ⁴ Pa.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A thin film containing a IIa-VIb group compound semiconductor as a base material is prepared by using a VIb group alone at a pressure higher than the critical pressure for dissociation of a VIb group element from a IIa-VIb group compound, or a VIb of dimethyl or diethyl. Deposition of the evaporation source of the IIa-VIb group compound can be suppressed to some extent by forming the film in a gas atmosphere of the group compound.

The IIa-VIb group compound semiconductor EL thin film thus formed still contains VIb group vacancies and oxygen, and the emission brightness is not sufficiently high. These E
The L thin film has a pressure of 10 ³ to 10 ⁴ Pa, which is much higher than that at the film formation
Group VIb alone, or VIb of dimethyl or diethyl
The heat treatment of the group compound in a gas atmosphere not only fills the holes of the group VIb element but also replaces oxygen with the group VIb element.

Regarding the promotion of the above-mentioned action, the following is important. By increasing the decomposition temperature of the 8-membered ring molecule of the VIb group element to 200 ° C. or higher as in the present invention,
Since the VIb group element gas contains a large amount of diatomic molecules having a size smaller than that of polyatomic molecules of 4 atoms or more, it easily penetrates into the light emitting layer in a short time during the heat treatment to cause a reaction.

Further, the gas of the VIb group compound of dimethyl or diethyl used in the present invention contains only one VIb group atom per molecule, and is easily decomposed to produce a VIb group element simple substance, so that it contains many diatomic molecules. It is more likely to enter the EL layer deeper in a short time than in a VIb group element simple gas atmosphere and cause a reaction. A method of manufacturing a double insulating layer structure EL element which is common to all the following examples will be described below.

Using a non-alkali glass of 50 × 50 mm ² as a substrate, an ITO film having a thickness of 170 nm is formed on the surface by a sputtering method, then a silicon dioxide film having a thickness of 30 nm is formed, and further a silicon nitride film having a thickness of 180 nm is formed. To film. An EL layer is formed thereon in a gas atmosphere of any one of sulfur, diethyl sulfide and dimethyl sulfide as described in detail in the following examples, and an inert gas and one of sulfur, diethyl sulfide and dimethyl sulfide is formed. After heat treatment in a gas atmosphere with gas,
A 180 nm silicon nitride film and a 30 nm silicon dioxide film are formed. Finally, an aluminum film having a film thickness of 400 nm is formed as an electrode.

The brightness of the EL device thus manufactured was evaluated by applying a sine wave of 1 kHz between the ITO film and the aluminum electrode film and measuring with a commercially available brightness meter. The light emission intensity when a voltage of light emission start voltage +60 V is applied is the luminance of the light emitting layer. Example 1 As an example of the present invention, a method for manufacturing an EL layer of SrS doped with Eu will be described.

SrS doped with 0.1 mol% of Eu
Using sinter pellets as evaporation source, film thickness of 8
A film of SrS of 00 nm was formed. The substrate temperature was 500 ° C. In order to examine the effect of the gas atmosphere during film formation, the atmosphere during film formation was a sulfur (hereinafter referred to as S) gas atmosphere, and the pressure range of S in the S gas atmosphere was 2.7 × 10 ^{−3 to} 8.0 × 10 ^−1. Pa
And In order to secure the pressure of S, the temperature of the entire film forming chamber is set to 2
The temperature was maintained at 00 ° C or higher. The EL layer was not heat-treated in an S gas atmosphere.

FIG. 1 shows the pressure of the S gas atmosphere during film formation.
It is a graph of the brightness. Line 1x is the gas atmosphere during film formation
Is the residual gas from the atmosphere without the introduction of a specific gas.
4.0 x 10^-3Luminance when Pa and no heat treatment
Is. From FIG. 1, the brightness in the S gas atmosphere is indicated by the broken line 1x.
8.0 x 10 than the brightness with residual gas shown^-3~ 6.7 x 10 ^-2
It was found that the pressure exceeded the Pa S gas atmosphere pressure range.
It Of the effect of the pressure of the S gas atmosphere during film formation on the brightness
Optimal value is 2.7 x 10^-2It turns out that it is Pa. Next, S
The effect of heat treatment in the atmosphere was investigated. Atmosphere during film formation
Is the residual gas. The heat treatment atmosphere of the EL layer is Ar and S
It is a mixed gas and the total pressure is 1 atm (about 1 × 10^FivePa)
Was. The partial pressure range of S is 2.7 × 10^Four~ 8.0 x 10^FourP
a, the substrate temperature range is 560 to 700 ° C., and the heat treatment time is 1
It was time.

FIG. 2 is a graph of luminance against partial pressure of S during heat treatment in an S gas atmosphere. A broken line 1x similar to that in FIG. 1 is additionally shown in FIG. From Fig. 2, 63 during heat treatment
It can be seen that the luminance exceeds the broken line 1x when the partial pressure range of S is 2.7 × 10 ^{4 to} 8.0 × 10 ⁴ Pa at 0 ° C. The optimum value of the partial pressure of S is 5.3 × 10 ^{4 to} 6.0 × 10 ⁴ P regardless of the substrate temperature.
It can be seen that the optimum value of the substrate temperature is 630 ° C.

FIG. 3 is a brightness graph with respect to the applied voltage of the EL element when the pressure of the S gas atmosphere at the time of film formation and the partial pressure of S at the time of heat treatment are paired. Table 1 shows these manufacturing conditions.

[0025]

[Table 1] It can be seen from FIG. 3 that the light emission start voltage hardly changes, but the luminance changes greatly, and the luminance of C is the best. It can be seen that the optimum pressure is C curve, which is 2.7 × 10 ^-2 Pa during film formation and 5.3 × 10 ⁴ Pa during heat treatment. Embodiment 2 As another embodiment of the present invention, Ce-doped SrS
The method for manufacturing the EL layer of is described.

Using a sintered pellet of SrS doped with 0.2 mol% of Ce as an evaporation source, a film thickness of 80 was obtained by the EB method.
A 0 nm SrS film was formed. The substrate temperature was 550 ° C. In order to investigate the effect of the gas atmosphere during film formation, the gas atmosphere during film formation was a diethyl sulfide (hereinafter referred to as DES) gas atmosphere, and the pressure range was 8.0 × 10 ^-4 to 8.0 × 10 ^-3 Pa.
And

The EL layer was not heat-treated in a DES gas atmosphere. FIG. 4 is a graph of luminance against pressure in the DES gas atmosphere during film formation. The straight line 2x is the brightness of the EL layer when the optimum pressure of the S gas atmosphere during film formation is 2.7 × 10 ⁻² Pa and the optimum partial pressure of S in the S gas atmosphere during heat treatment is 5.3 × 10 ⁴ Pa. This experimental result shows that the effect of the DES gas atmosphere on the brightness exceeds the effect of the S gas atmosphere in the DES gas atmosphere in the pressure range of 8.0 × 10 ⁻⁴ to 8.0 × 10 ⁻³ Pa. It can be seen from FIG. 4 that the optimum pressure for the effect of the DES pressure on the luminance during film formation is 2.7 × 10 ⁻³ Pa.

Next, the effect of heat treatment in a DES gas atmosphere
I checked the fruit. The atmosphere during film formation is residual gas and the pressure is 4.0 ×
Ten^-3Pa. The heat treatment atmosphere of the EL layer is Ar and DE
A mixed gas of S was used and the total pressure was 1 atm. DES partial pressure range
Box is 1.3 × 10³~ 8.0 x 10³Pa, substrate temperature 630 ° C
And Figure 5 shows DE during heat treatment in DES gas atmosphere.
It is a graph of the brightness | luminance with respect to the partial pressure of S. The above figure is shown in FIG.
A straight line 2x similar to that of No. 4 is added. After all, DES
The effect on brightness of the atmosphere is 1.3 × 10³~ 8.0 x 10³
In the partial pressure range of DES, the broken line 2x, that is, S or more,
Is shown. Optimal DES partial pressure is 5.3 x 10 ³Pa
It turns out that

FIG. 6 is a luminance graph with respect to the applied voltage of the EL element when the pressure of the DES gas atmosphere during film formation and the partial pressure of DES during heat treatment are paired. Table 2 shows these conditions.

[0030]

[Table 2] It can be seen from FIG. 6 that the light emission start voltage hardly changes, but the brightness changes greatly, and G has the best brightness. It can be seen from Table 2 that the optimum pressures during film formation and during heat treatment are G curves, which are 2.7 × 10 ⁻¹ and 5.3 × 10 ⁴ Pa, respectively. Example 3 As another example of the present invention, Ce-doped SrS
The method for manufacturing the EL layer of is described.

SrS doped with 0.2 mol% of Ce
A film thickness of 6 is obtained by the EB method using the sintered pellets of
A film of SrS of 00 nm was formed. Substrate temperature is 500 ° C
Was. In order to investigate the effect of atmospheric gas during film formation,
Atmosphere gas of dimethyl sulfide (hereinafter referred to as DMS) atmosphere
I was worried. The pressure range of DMS gas atmosphere is 5.3 × 10 ^-Four~
1.3 x 10^-2It was Pa.

The EL layer was not heat-treated in a DMS gas atmosphere. FIG. 7 is a graph of luminance against pressure in the DMS gas atmosphere during film formation. The broken line 3x represents the brightness of the EL layer when the optimum pressure in the S gas atmosphere during film formation is 2.7 × 10 ⁻² Pa and the optimum partial pressure of S during heat treatment is 5.3 × 10 ⁴ Pa.
The results of this experiment show that the effect on the brightness of the DES gas atmosphere is the effect of the S gas atmosphere and that of the DMS gas atmosphere is 6.7 × 10 ^-4 .
It shows that it exceeds 1.2 × 10 ^-2 Pa. Figure 7
From this, it is understood that the optimum value of the effect of the pressure of the DMS gas atmosphere on the brightness during film formation is 2.7 × 10 ⁻³ .

Next, the effect of heat treatment in a DMS gas atmosphere was investigated. The atmosphere during film formation is residual gas and the pressure is 4.0 ×
It is 10 ⁻³ Pa. The heat treatment atmosphere of the EL layer is Ar and DM
A mixed gas of S was used and the total pressure was 1 atm. Of which DMS
The partial pressure range was 5.3 × 10 ^{3 to} 1.9 × 10 ⁴ Pa and the substrate temperature was 630 ° C. FIG. 8 is a graph of luminance against partial pressure of DMS during heat treatment in a DMS gas atmosphere. A broken line 3x is additionally shown in FIG. 8 similarly to the description in FIG.
It can be seen from FIG. 8 that the partial pressure of DMS exceeds the brightness in the broken line 3x, that is, in the S gas atmosphere, in the range of 6.7 × 10 ^{3 to} 1.2 × 10 ⁴ Pa. The optimum value is D when the substrate temperature is 630 ° C.
It can be seen that the partial pressure of MS is 1.3 × 10 ⁴ Pa.

FIG. 9 is a luminance graph with respect to the applied voltage of the EL element when the pressure of the DMS gas atmosphere during film formation and the partial pressure of DMS during heat treatment are paired. Table 3 shows these conditions.

[0035]

[Table 3] From FIG. 9, it can be seen that the light emission start voltage hardly changes, but the brightness changes greatly, and K has the best brightness. It can be seen from Table 3 that the optimum pressures during film formation and heat treatment are 2.7 × 10 ⁻³ and 1.3 × 10 ⁴ Pa for the K curve, respectively. Example 4 As yet another example of the present invention, a method of manufacturing an EL layer of SrSe doped with Ce will be described.

SrS doped with 0.1 mol% of Ce
Using the sintered pellet of e as an evaporation source, SrSe having a film thickness of 600 nm was formed by the EB method. Substrate temperature is 400 ° C
And In order to investigate the effect of the atmosphere during film formation, the atmosphere during film formation was Se gas atmosphere, and the pressure range of Se gas atmosphere was 8.0 × 10 ⁻³ to 8.0 × 10 ⁻² Pa.

The heat treatment of the EL layer in the Se atmosphere was not performed. FIG. 10 is a graph of the luminance against the pressure of the Se gas atmosphere during film formation. The straight line 4x is the luminance when the atmosphere during film formation is residual air and the pressure is 2.7 × 10 ⁻³ Pa, and the heat treatment is not performed. From FIG. 10, it can be seen that the curing with respect to the luminance in the Se atmosphere is higher than the luminance with the broken line 4x, that is, with the residual gas in the range of 9.3 × 10 ^{−3 to} 6.7 × 10 ⁻² Pa. It can be seen that the optimum value of the effect of the pressure of the Se gas atmosphere on the brightness during film formation is 2.7 × 10 ^-2 Pa.

Next, the effect of heat treatment in a Se gas atmosphere
I checked. The atmosphere during film formation is residual gas and the pressure is 2.7 × 10
^-3Pa. The heat treatment atmosphere of the EL layer is made of Ar and Se.
A mixed gas was used and the total pressure was 1 atm. Partial pressure of Se
Range 3.3 x 10³~ 4.0 x 10 ^FourPa, substrate temperature range 5
It was set to 80 ° C. Figure 11 shows heat treatment in Se gas atmosphere.
5 is a graph of luminance against partial pressure of Se in FIG. From Figure 11
Se is 6.7 x 10³~ 3.3 x 10^FourBroken line 4 in the partial pressure range of Pa
x, that is, the brightness is higher than that of the residual gas.
It The optimum value is the partial pressure of Se when the substrate temperature is 630 ℃ 2.
0 x 10^FourIt turns out that it is Pa.

FIG. 12 is a brightness graph with respect to the applied voltage of the EL element when the pressure of the Se gas atmosphere during film formation and the Se partial pressure J during heat treatment are paired. Table 4 shows these conditions.

[0040]

[Table 4] From FIG. 12, it can be seen that the light emission start voltage hardly changes, but the luminance changes greatly, and O has the best luminance. It can be seen from Table 4 that the optimum pressures during film formation and during heat treatment are 2.7 × 10 ⁻⁴ and 2.0 × 10 ⁴ Pa for the O curve, respectively.

[0041]

According to the present invention, a thin film containing a IIa-VIb group compound semiconductor as a base material is prepared by using a group VIb simple substance having a pressure higher than the critical pressure for the dissociation of the VIb group element from the IIa-VIb group compound or dimethyl group. Alternatively, by forming a film in a gas atmosphere of a VIb group compound of diethyl, decomposition of the evaporation source of the IIa-VIb group compound is suppressed to some extent, and further, VIb of 10 ³ to 10 ⁴ Pa at a pressure much higher than that at the time of film formation is used. EL thin film with high brightness in a short time, not only filling the holes of VIb group element by heat treatment of group VI simple substance or VIb group compound of dimethyl or diethyl in gas atmosphere but also replacing oxygen with VIb group element Can be obtained.

[Brief description of drawings]

FIG. 1 is a graph of luminance against pressure in an S gas atmosphere during film formation.

FIG. 2 is a graph of luminance against partial pressure of S during heat treatment in an Ar—S atmosphere.

FIG. 3 is a brightness graph with respect to an applied voltage of an EL element formed and heat-treated in an S atmosphere.

FIG. 4 is a graph of luminance against pressure in a DES gas atmosphere during film formation.

FIG. 5 is a graph of luminance against partial pressure of DES during heat treatment in an Ar-DES atmosphere.

FIG. 6 is a luminance graph with respect to an applied voltage of an EL element formed and heat-treated in a DES atmosphere.

FIG. 7 is a graph of luminance against pressure in a DMS gas atmosphere during film formation.

FIG. 8 is a graph of luminance against partial pressure of DMS during heat treatment in an Ar-DMS atmosphere.

FIG. 9 is a luminance graph with respect to an applied voltage of an EL element formed and heat-treated in a DMS atmosphere.

FIG. 10 is a graph of luminance against pressure of Se gas atmosphere during film formation.

FIG. 11 is a graph of luminance against Se partial pressure during heat treatment in an Ar—Se atmosphere.

FIG. 12 is a luminance graph against applied voltage of an EL element that is formed and heat-treated in an Se atmosphere.

FIG. 13 is a sectional view of a double insulating layer structure EL device.

[Explanation of symbols]

 1 Glass Substrate 2 Transparent Electrode Layer 3 First Insulating Layer 4 EL Light Emitting Layer 5 Second Insulating Layer 6 Back Electrode Layer A to P Luminance Curve

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical indication H05B 33/14 H05B 33/14

Claims (6)

[Claims] 1. A thin film comprising a Group IIa-sulfur compound semiconductor as a base material is formed in a gas atmosphere selected from low-pressure sulfur, diethyl sulfide and dimethyl sulfide, and then an inert gas at normal pressure is used. A method for producing an electroluminescent thin film, which comprises heat-treating in a gas atmosphere with any of the above gases. 2. The manufacturing method according to claim 1, wherein the pressure of the sulfur gas atmosphere during film formation is 8.0 × 10 ^{−3 to} 6.7 × 10 ⁻² P.
a and the partial pressure of sulfur with respect to the inert gas during heat treatment is
2.7 × 10 ^{4 to} 8.0 × 10 ⁴ Pa, a method for producing an electroluminescent thin film. 3. The manufacturing method according to claim 1, wherein the pressure of the diethyl sulfide gas atmosphere during film formation is 8.0 × 10 ⁻⁴ to 8.0.
A method for producing an electroluminescent thin film, characterized in that it has a pressure of × 10 ^-3 Pa and a partial pressure of diethyl sulfide to an inert gas during heat treatment of 1.3 × 10 ^{3 to} 8.0 × 10 ³ Pa. 4. The manufacturing method according to claim 1, wherein the pressure of the dimethyl sulfide gas atmosphere during film formation is 6.7 × 10 ^{−4 to} 1.2.
× 10 ^-2 is Pa, the manufacturing method of the electroluminescent film, wherein the partial pressure to an inert gas of dimethyl sulfide during the heat treatment is ^{6.7 × 10 3 ~1.7 × 10 4} Pa. 5. Production of an electroluminescent thin film in which a thin film containing a group IIa-selenium compound semiconductor as a base material is formed in a low-pressure selenium gas atmosphere and then heat-treated in an atmosphere of an inert gas and selenium gas at normal pressure. Method. 6. The manufacturing method according to claim 5, wherein the pressure of the selenium gas atmosphere during film formation is 9.3 × 10 ^{−3 to} 6.7 × 10 ^−2.
Pa, and the partial pressure of selenium to the inert gas at the time of heat treatment is 6.7 × 10 ^{3 to} 3.3 × 10 ⁴ Pa, the method for producing an electroluminescent thin film.