JPH03231253A - X-ray electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance contrast of an electrostatic latent image by successively laminating on a conductive substrate an X-ray phosphor layer, an inorganic semiconductor layer, an organic semiconductor layer, and a transparent insulating layer. CONSTITUTION:The X-ray phosphor layer 2, the inorganic semiconductor layer 3, the organic semiconductor layer 4, and the transparent insulating layer 5 are successively laminated on the conductive substrate. The inorganic semiconductor layer 3 is more sensitive to the visible light on the shorter wavelength side, as compared with a usual Se layer, and the X-ray phosphor layer 2 has a large light emitting region on the shorter wavelength side in the visible light on exposure to X-rays. When X-rays are transmitted through the layers 5, 4, and 3, and reaches the layer 2, it is allowed to emit the visible light, and the layer 3 receives it, thus permitting the contrast of the electrostatic latent image to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an X-ray electrophotographic photoreceptor suitable for reverse electric field method.

[Prior art and its problems] 1950, McMaster and 5charf fe
rt discovered that a selenium (Se) deposited layer has X-ray sensitivity, opening up a new field of application for electrophotography. According to this X-ray electrophotograph, medical X-ray diagnosis and
When non-destructive testing is performed using X-ray photography, it is characterized by the fact that images with higher contrast can be obtained compared to conventional X-ray photography using silver salts.

That is, on a conductive flat substrate such as an aluminum (,l) plate, an optical layer of Se or Se and ^52Se or Se is formed.
A photosensitive layer is formed by laminating 5e-Te and 5e-Te, and this sheet-like photoreceptor is placed in a cassette or holder, and a shutter that can be opened and closed is covered thereto to shield or protect the photoreceptor from light. An X-ray electrophotographic photoreceptor having such a configuration has excellent image clarity and contrast gradation due to the edge effect, and allows fine structures to be clearly imaged. Therefore, it is suitable for exposing bones such as vertebrae and ribs of hands, feet, shoulders, and neck, as well as soft tissues such as breast cancer examinations.

However, in the case of the above-mentioned X-ray electrophotographic photoreceptor, the screen type X
The problem is that the sensitivity is lower than that of line film, ranging from one-tenth to one-tenth.

Therefore, for example, it is not suitable for irradiating thick parts such as vertebrae in the abdomen, pelvis, and lumbar region because the amount of radiation will be large.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photoreceptor for X-ray electrophotography which is capable of increasing the sensitivity and the contrast of a charge latent image.

[Means for solving problems]

The X-ray electrophotographic photoreceptor of the first invention includes an X-ray phosphor layer,
The X value of the amorphous silicon (hereinafter abbreviated as a-5i) layer and the compositional formula S i l-X Cx satisfies Q < x < 0.
Amorphous silicon carbide represented by 5 (hereinafter a)
-SiC) layers are laminated so that their optical bandgaps are different from each other, and each layer has a thickness of 20 to 500 layers.It has a structure in which an inorganic semiconductor layer, an organic semiconductor layer, and a transparent insulating layer are sequentially laminated.

Further, the photoreceptor of the second invention includes an X-ray phosphor layer, a transparent conductive layer,
It has a structure in which the above-mentioned inorganic semiconductor layer, organic semiconductor layer, and transparent insulating layer are sequentially laminated on a substrate.

Furthermore, the photoreceptor of the third invention has X on the entire surface of the transparent substrate.
It has a structure in which a linear phosphor layer is formed, at least the other main surface is electrically conductive, and the above-mentioned inorganic semiconductor layer, organic semiconductor layer, and transparent insulating layer are sequentially laminated on the electrically conductive main surface.

Furthermore, the photoreceptor of the fourth invention has an X-ray phosphor layer and a composition formula s;+
- An inorganic semiconductor layer, an organic semiconductor layer, and a transparent insulating layer are laminated with aSiC layers in which the X value of It has a sequentially laminated structure.

The present invention will be explained in detail below.

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 each show layer configurations showing four types of embodiments of the present invention.

First, according to FIG. 1, an X-ray phosphor layer (2), an inorganic semiconductor layer (3), and an organic semiconductor layer (4) are formed on a conductive substrate (1).
and a transparent insulating layer (5) are sequentially laminated.

According to Mr. B in Figure 1, the inorganic semiconductor layer (3) is
It is highly sensitive to visible light on the short wavelength side compared to the e layer,
Furthermore, when the X-ray phosphor layer (2) is irradiated with X-rays, it has a large emission region in visible light on the shorter wavelength side. Then, the X-rays pass through the organic semiconductor layer (4) and the inorganic semiconductor layer (3), and the
When the linear phosphor layer (2) is reached, visible light is emitted along with the light reception 62, and the visible light is received by the inorganic semiconductor layer (3). A feature of the present invention is that when a charge latent image is formed by a reverse electric field method using a photoreceptor whose sensitivity is significantly increased by such light emission and light reception, a charge latent image with high contrast can be obtained.

The substrate (1) may be a metal conductor such as copper, brass, SUS, Al, or Ni, or an insulator such as glass or ceramic coated with a conductive thin film.

This substrate (1) may be a sheet-like, belt-like or web-like flexible conductive sheet; such a sheet may include A1;
A/, metal such as Ni or SnO□, composite oxide of indium and tin: fTO (Indium T
A transparent conductive material such as (in oxide) or an organic conductive material subjected to conductive treatment such as vapor deposition is used.

The following types are used for the X, vI phosphor layer (2).

Sulfide type...ZnS:Ag, (Zn, Cd)S: 8g
, (Zn, Cd)S:Cu, (Zn,Cd)S:C
u, Ag, etc., tungstate type...Ca-04, Mg-04, Ca-04:Pb, etc. Terbium activated rare earth oxysulfide type'...YzO'zS:Tb, Gd20zS:T,
LazOzS:Tb.

(Y, Gd)zOzs:Tb 1(Y,Gd)zOzs
:Tb, Tm, etc. terbium-activated rare earth phosphate system YPO, :Tb 5GdPO, :Tb, La
PO, :Tb etc. Terbium activated rare earth oxyhalide system... La0Br:Tb, La0B
r: Tb, Tm.

La0C1:Tb, La0C1:Tb, Tm.

Thulium-activated rare earth oxyhalide system such as Gd0Br:Tb, Gd0C1:Tb...La0Br:Tm,
Barium sulfate system such as La0C1:Tm...Ba5O,:Pb, Ba5Ot:Eu" (Ba
, 5r) SO4:Eu"su divalent europium activated alkaline earth metal phosphate system...
Ba, (PO4)2:Eu2F (Ba, Sr):I (PO4)2:Eu" Equivalent divalent europium activated alkaline earth metal fluoride halide system...BaFCl:Eu", BaFBr:Eu"BaFC
l:Eu'', Tb, BaFBr:Eu'', Tb, B
aFz・BaCl21(C1:Eu”(Ba, Mg)F
z HBaC1z・KCl: Iodide system such as Eu24 --
CsI:N'a, Csr:Tl, Nal, Kl:T
Primary hafnium phosphate system...HfP2O, :Cu etc.Europium activated rare earth oxysulfide system...YzOzS:Eu1GdzOzS:Eu 1La
20zS: Eu % (Y, Gd)zOzs: Europium activated rare earth oxide system such as Eu... YJ3: Eu -Gdz032Eu
.

La, 0. :Eus (Y,Gd)zO:+:Europium-activated rare earth phosphate system such as Eu...YPO4:Eu, GdPO4:Eu, La
PO4: Eu, etc. Eurobium activated rare earth vanadate system YVOn: Eu % GdVO4: Eu, LaVO
4:Eu.

(Y, Gd) VO4:Eu, etc. These X-ray phosphor layers (2) can be formed by thin film forming methods such as plasma MOCVD method using RF or ECR, sputtering method, vacuum deposition method, or by coating phosphor particles with polymer resin. It is formed by a thick film forming method of mixing with a binder such as and applying it.

Examples of the binder used in the latter thick film forming means include the following.

Proteins...Gelatin and other polysancharides...Natural polymeric substances such as dextran...Synthetic polymeric substances such as gum arabic...Polyvinyl butyral, polyvinyl acetate, nitrocellulose, ethylcellulose, hynylidene chloride/vinyl chloride copolymer, Polyalkyl (meth)acrylate, vinyl chloride/vinyl acetate copolymer, polyurethane, cellulose acetate butyrate, polyvinyl alcohol, linear polyester, among others, nitrocellulose, linear polyester, polyalkyl (meth)acrylate, nitrocellulose and linear A mixture with polyester and a mixture of nitrocellulose and polyalkyl (meth)acrylate are desirable because they are excellent in the dispersibility of phosphor particles, the stability of coating film formation, and the transparency to fluorescence.

The thickness of the X-ray phosphor layer (2) is 1 to 10 μm if it is a thin film, preferably 2 to 8 μm, and preferably 20 to 500 μm if it is a thick film. ~300
Any μ amount is sufficient.

Regarding the inorganic semiconductor layer (3), the a-5i layer and the a-5i
It has a superlattice structure layer structure in which CFfls are combined and laminated alternately, and the optical band gap of both layers (hereinafter referred to as optical band gap is abbreviated as Eg) is made to be different from each other. By setting the thickness within a predetermined range, this increases the amount of photocarriers generated, increases the mobility of the photocarriers, and lengthens the lifetime, resulting in high photosensitivity and low residual potential. Become.

The thickness of each of the above layers is 20 to 500 people, preferably 30 to 500 people.
It is sufficient to set the range to 300 people, and this range significantly increases the light sensitivity. When the thickness of each layer is less than 20 layers, sufficient conduction due to the tunneling effect of carriers generated within the superlattice structure cannot be obtained, and good running properties and life of the carriers cannot be obtained.

Furthermore, when the number of people exceeds 500, the kinetic energy of carriers obtained by the tunnel effect is lost due to scattering within each layer.
Good runnability and life of the carrier cannot be obtained.

Further, each of the above layers only needs to have excellent photoconductivity, and for this purpose, the composition of one a-3iC layer may be set as follows.

Composition formula 5il-XCX 0<X<0゜5 Preferably 0.05<x<0.4 When the above X value is 0.5 or more, the photoconductive layer becomes extremely low, and the photocarrier excitation function is impaired. descend.

The a-Si layer only needs to have an excellent photoconductive layer, and the a-Si layer may contain germanium (Ge), tin (Sn), and oxygen (0) within the range where Eg is different from the a-5iCJii above. , nitrogen (N) and carbon (C)
It may also contain at least one element selected from.

The inorganic semiconductor layer (3) with such a superlattice structure contains hydrogen (
H) elements and halogen elements are contained for the termination of dangling bonds, but among these elements, the H element is easily incorporated into the termination, which causes the localized level density in Eg to disappear. desirable in that respect. Further, the thickness of the inorganic semiconductor layer (3) is 0.05 to 5 μm, preferably 0.05 to 5 μm.
It is sufficient if it is in the range of 1 to 3 μm, and within this range,
High photosensitivity is obtained and residual potential is low.

Furthermore, the inorganic semiconductor layer (3) may be made to contain a Group Ma element (hereinafter abbreviated as Ma group element) or a Group Va element (hereinafter abbreviated as Va group element) of the periodic table for negative charging or positive charging. A suitable electrophotographic photoreceptor can be produced.

When the NLA group element is contained in an amount of 1 to 11,000 ppm, it is suitable for negative charging, and when the Va group element is contained in an amount of 500 ppm or less, or when these older elements are not contained, it is suitable for positive charging.

The above I [group 1a elements include B, ^1. Although there are elements such as Ga + In, element B is preferable because it has excellent covalent bonding properties and can sensitively change semiconductor properties, and also provides excellent charging ability and photosensitivity.

Further, Va group elements include elements such as N, P, As, Sb, and old, but it is preferable to use the P element for the same reason as above.

To form such an inorganic semiconductor layer (3), there are thin film forming methods such as a glow discharge decomposition method, an ion blating method, a reactive sputtering method, a vacuum evaporation method, and a CVD method.

Further, the photoreceptor of the present invention can be set to be a negatively charged type or a positively charged type by selecting a material for the organic semiconductor layer (4).

That is, in the case of a negatively charged photoreceptor, an electron-donating compound is selected for the organic semiconductor layer (4), while in the case of a positively charged photoreceptor, an electron-withdrawing compound is selected for the organic semiconductor layer (4). .

Electron-donating compounds include poly-N-
Examples include vinylcarbazole, polyvinylpyrene, polyvinylanthracene, pyrene-formaldehyde condensation polymer, and low molecular weight ones such as oxadiazole,
These include oxazole, pyrazoline, triphenylmethane, hydrazone, triarylamine, N-phenylcarbazole, and stilbene.These low-molecular substances include polycarbonate, polyester, methacrylic resin, polyamide, acrylic epoxy, polyethylene, phenol, polyurethane, and butyral resin. It is used after being dispersed in a binder such as polyvinyl acetate or urea resin.

Electron-withdrawing compounds include 2.4.7-)linitrofluorenone.

The organic semiconductor layer is formed by a dip coating method or a coating method. In the former method, the photosensitive material is immersed in a coating solution in which it is dispersed in a solvent, then pulled up at a constant speed, and then
This method involves natural drying and heat aging (approximately 150°C, approximately 1 hour), and the latter coating method involves applying a photosensitive material dispersed in a solvent using a coater <=n>. , followed by hot air drying.

The transparent insulating layer (5) may be formed of either an organic material or an inorganic material.

Examples of organic materials include mylar, polycarbonate, polyester, polyvaraxylene, etc., and are formed by coating or gluing.

Inorganic materials are selected that have a sufficiently large optical breadth, are transparent to visible light, and have high resistance, such as amorphous silicon, silicon carbide, silicon nitride, silicon oxide, and silicon oxycarbide. , silicon oxynitride, etc., which are formed by thin film forming means.

The thickness of the transparent insulating layer (5) is 2 to 50μ, preferably 5 to 50μ
If it is less than 2μ, this N
In (5), a sufficient potential cannot be maintained, and as a result, the surface potential cannot be increased or the potential contrast cannot be increased, and when used repeatedly, the life is shortened due to wear. If it exceeds 50 μm, the electric field (1 is the electric force wA) in this N(5) will spread in the direction of the film surface when forming a fine charge pattern, resulting in a decrease in resolution and insufficient Can't get resolution.

Thus, according to the embodiment of FIG. 1, high sensitivity is achieved by forming the inorganic semiconductor layer (3) that has high sensitivity to visible light on the short wavelength side, and moreover, the transparent insulating layer (5) is formed. As a result, it was possible to provide an x441Ait photographic photoreceptor in which the contrast of the charge latent image was enhanced using the reverse electric field method.

Next, in the case of pG shown in Fig. 2, on the substrate (6) there is an
), an organic semiconductor layer (4) and a transparent insulating layer (5) are sequentially laminated, and compared to the embodiment shown in Fig. 1, a transparent conductive layer (7) is formed, and X-rays are transparent. Insulating layer (5
), the organic semiconductor layer (4), the inorganic semiconductor layer (3), and the transparent conductive layer (7). The light is received by the inorganic semiconductor layer (3) via the transparent conductive layer (7),
The feature is that the sensitivity is significantly increased by such light emission and light reception.

The XvA phosphor Fii (2) with this configuration, the inorganic semiconductor layer (
3), the organic semiconductor layer (4) and the transparent insulation N (5) are the first
It may be the same as each layer shown in the embodiment of the figure.

Furthermore, since some of the photocarriers generated in the inorganic semiconductor FJ (3) flow to the transparent conductive layer (7), the substrate (6) may be either conductive or insulating.

If the substrate (6) is conductive, it may be the same as the substrate (1), and if it is insulative, it may be glass or a polymeric sheet such as a polyester film.

The transparent conductive layer (7) is made of ITO, 5nOz, etc., and its formation methods include sputtering, vapor deposition, and coating.

Thus, even in the embodiment shown in FIG. 2, a highly sensitive X-ray electrophotographic photoreceptor could be provided.

In the embodiment shown in FIG. 3, an X-ray phosphor layer (2) is formed on the main surface of the transparent substrate (8), and the other main surface is at least electrically conductive, and Inorganic semiconductor layer (3
), an organic semiconductor layer (4), and a transparent insulating layer (5) are laminated, and substrate(
8) and reaches the X-ray phosphor layer (2), visible light is emitted as the light is received, and the visible light is transmitted through the transparent substrate (2).
The light is received by the inorganic semiconductor layer (3) via the transparent insulating layer (5), and the sensitivity is increased by this light emission and light reception.
It is characterized by the fact that the contrast of the charge latent image is significantly enhanced by forming a reverse electric field method.

An X-ray phosphor layer (2) with this configuration, an inorganic semiconductor layer (3),
The organic semiconductor layer (4) and the transparent insulating layer (5) may be the same as the respective layers shown in the embodiment of FIG.

Further, the transparent substrate (8) may be transparent conductive over its entirety, or may be electrically conductive on only one main surface. In the former case, there is a plate-like body made of ITO or Snug, and in the latter case, for example, it is placed on a transparent insulating resin substrate.

A thin metal layer such as Ni, ＾g+ Au, Cr, or Tt is deposited to maintain transparency, or ITO, 5
A transparent conductive layer such as nOz may also be formed.

In this manner, also in the embodiment shown in FIG. 3, it was possible to provide a photoreceptor for X-ray electrophotography with a high degree of anger and a high contrast.

In the embodiment shown in FIG. 4, the layer structure is such that the following inorganic semiconductor layer (9) and organic semiconductor layer (4) are sequentially laminated on the conductive substrate (1), and the present invention is applied to the inorganic semiconductor layer (9). The organic semiconductor N(
4) has a charge transport function, and is characterized in that the sensitivity of XvA is significantly increased by using such a functionally separated photoreceptor.

First, the inorganic semiconductor layer (9) has a layer structure in which an xvA phosphor layer and an a-5iC layer are combined and laminated alternately, and the thickness of each layer is set within a predetermined range. This increases the amount of visible light that accompanies the reception of X-rays, especially visible light on the short wavelength side, and in addition, the visible light is
The 5iC layer efficiently receives light, thereby increasing the amount of optical carriers generated as x'ia light is received by the inorganic semiconductor layer (9).

In order to obtain such effects, the thickness of each of the above layers may be set within a range of 50 to 2,000 people, preferably 50 to 1,000 people. If this thickness is less than 50, the characteristics of the X-ray phosphor layer emitting light upon receiving X-rays and a
The characteristics of the −5iC layer absorbing light and generating carriers are both insufficient, and good carrier excitation characteristics cannot be obtained. Furthermore, when the number of people exceeds 2000, the emission of the X-ray phosphor layer and the light absorption of the a-5iC layer become sufficiently large, but on the other hand, the carriers generated in the a-5iCr WJ become
Due to the tunnel effect, the carrier cannot travel well in the IA phosphor layer, and as a result, good carrier excitation characteristics cannot be obtained.

The composition of the a-5iC layer, which is one of the layers in the above laminated structure, may be set as follows.

Compositional formula: Si, -, CX Q < x < Q, 5 Preferably 0.05 < x < 0.4 When the above X value is 0.5 or more, the photoconductivity becomes extremely low and the excitation of photocarriers Function deteriorates.

Such a-SiC layer contains hydrogen (H) element and halogen element for dangling bond termination, but among these elements, H element is easily incorporated into the termination part, and this causes This is desirable in that the localized level density of is reduced.

Further, by incorporating a Ma element or a Group Va element into the a-SiC layer, an electrophotographic photoreceptor suitable for negative charging or normal charging can be obtained.

(2) When the A-group element is contained in an amount of 1 to 11,000 ppm, it is suitable for negative charging, and when the Va-group element is contained in an amount of 500 ppm or less, or when these elements are not contained, it is suitable for positive charging.

In addition, according to each of the above-mentioned four types, although the case where X-rays are irradiated from the organic semiconductor layer (4) side is explained, the same effect can be obtained when X-rays are irradiated from the opposite side. Effects can be obtained.

Further, the reverse electric field method of this embodiment will be explained using the charge latent image process shown in FIG.

According to the same figure (A), (10) is the substrate, (11)
are inorganic semiconductor layer (3), organic semiconductor layer (4), XvA
It is a photosensitive layer consisting of a phosphor layer (2) and the like, and (12) is a transparent insulating layer.

In (B), corona charging is performed on the surface of the transparent insulating layer (12) while the entire surface is exposed to visible light, and the photo-excited carriers and the carriers injected from the substrate (10) are transferred to the photosensitive layer (11). moving inside, resulting in a transparent insulating layer (
Charges of the same polarity as the corona are induced on the surface of the transparent insulating layer (12) and the photosensitive layer (11), and charges of opposite polarity are induced on the interface between the transparent insulating layer (12) and the photosensitive layer (11).

As shown in (C), when corona charging with the opposite polarity to the corona charging in (B) is performed while performing image exposure with X-rays, photoexcited carriers and substrate The carriers injected from (10) quickly cancel out the charges accumulated on the surface at (B), and new charges of the opposite polarity are induced. In addition, in the area (b) where image exposure is not performed, only a part of the surface charge of the transparent insulating layer (12) is neutralized, and the charge accumulated at the interface between the transparent insulating layer (12) and the photosensitive layer (11) is remain.

Next, when the entire surface is uniformly exposed to visible light as shown in (D), in (C), the transparent insulation J! ! The charges accumulated at the interface between (12) and the photosensitive layer (11) are reduced to the same number as the charges on the surface of the transparent insulating layer (12) by photoexcited carriers and carriers injected from the substrate (10), and ( It will be as shown in E). As a result, a latent image with enhanced contrast is obtained.

〔Example〕

Next, an example will be described taking as an example a case in which each layer is formed on an Al conductive substrate by the following method.

X-ray phosphor layer...MOCVD method a-5iC layer...RF Blaze 7CVD method Organic semiconductor layer...Coating method Transparent insulating layer...Coating method and glow discharge decomposition device used in this example This will be explained with reference to FIG.

In the figure, the first tank (13), the second tank (14), and the third tank
Tank (15), 4th tank (16), 5th tank (1
7) respectively 5iHa, CJz, NH3, Bz
sealed with Ha (diluted with Hz gas) and H2, each of which is connected to a corresponding first regulating valve (18);
It is released by opening the second regulating valve (19), the third regulating valve (20), the fourth regulating valve (21), and the fifth regulating valve (22). The flow rate of the released gas is determined by the mass flow controller (23) (24) (25) (26).
(27), each gas is mixed and sent to the main pipe (28). Note that (29) and (31) are stop valves.

Gas flowing through the main pipe (28) flows into the reaction tube (31), and a capacitively coupled discharge electrode (32) is installed inside this reaction tube (31), and a cylindrical film-forming substrate (33) is placed on a substrate support (34), the substrate support (34) is rotationally driven by a motor (35), and the substrate (33) rotates accordingly. Then, the electrode (3
2) Apply high frequency power with a frequency of 1 to 50 MHz to 3), and heat the substrate (33) to about 200 to 400° C., preferably about 200 to 300° C., by appropriate heating means.
Heat to a temperature of 50°C. In addition, the reaction tube (31) is connected to a rotary pump (36) and a diffusion pump (37), which create a vacuum state (gas pressure at the time of discharge of 0.01 to 2.0 mm) required during film formation by glow discharge. 0 Torr) is maintained.

The substrate (3
3) When forming an a-SiC layer on top of the first regulating valve (
18), the second regulating valve (19) and the fifth regulating valve (22) are opened to release each gas of Si1(a, CzHz+Hz), and the released amount is controlled by the mass flow controller (23).
(24) and (27), each gas is mixed and flows into the reaction tube (31) via the main pipe (28).

Then, when the vacuum state inside the reaction tube, the substrate temperature, and the high-frequency power applied to the electrodes are set to predetermined conditions, a glow discharge occurs, and an a-5iC film is rapidly formed on the substrate as the gas decomposes.

(Example 1) In this example, a photoreceptor having the embodiment shown in FIG. 1 was produced.

First, a ZnS layer having a thickness of 3 μm as an X-ray phosphor layer was formed on an Al conductive substrate by MOCVD.

According to this MOCVD method, a ZnS layer is grown in a vapor phase by using dimethylzinc Zn(CHi)z and hydrogen sulfide H2S as source gases. And further copper (Cu)
In order to add an appropriate amount of aluminum (A), β-diketonate compound C0 (CslbOi)z and triethylaluminum Aj! (CJs)s are added.

Next, on the ZnS layer, an inorganic semiconductor layer (3) having a superlattice structure consisting of an a-SiC layer/a-Si layer is laminated to a thickness of 1 μm using the RF Blaze TCVD method under the film-forming conditions shown in Table 1. The composition of this layer (3) was measured by the XMA method.

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After that, an organic semiconductor layer (4) was formed to a thickness of 20 μm. According to its formation, 2.4.7-) Add 114 volumes of linitrofluorenone to 1,4-dioxane.
Container, and polyester resin (Refsan-LS2-1
1) was added, and ultrasonic dispersion was performed for 40 minutes. The solution thus obtained was applied using a bar coater and then
Hot air drying was performed at 0°C.

Thereafter, a polyester resin is coated on the organic semiconductor layer (4) to a thickness of about 15 μm, and a transparent insulating layer (5
).

In this way, an X-ray electrophotographic photoreceptor in which the bright area potential in the reverse electric field method was positively charged was fabricated.

In addition, as a comparative example, a positively charged photoreceptor was prepared by not forming a transparent insulating layer on the photoreceptor of this example and using the same layer structure as that of this example.

When the photoconductor of the comparative example was corona charged to +6kV based on the Carlson method, it showed a charge of +600V.Next, the photoconductor was irradiated with X-rays of 100kVp and 20a+^ for about 1 second, and its surface was When I measured the potential, it was +6
The contrast potential decreased to 0V, and a contrast potential (surface potential difference between bright and dark areas) of about 540V was obtained.

Next, the charging and sensitivity of the photoreceptor of this example were measured by a reverse electric field method. In this case, the surface potential has a reverse polarity compared to the comparative example.

That is, when charging was performed using a corona charger that applied a voltage of 6 kV while exposing the entire surface of the photoreceptor to white light,
It shows a charge of about -930v, and +6kV (7):!
t) + charging, 100 kV, 2 On + A (
7) X-ray irradiation was performed for about 1 second, and then the entire surface of the photoreceptor was exposed to white light to measure the surface potential. The result was -450V in the dark area (B) and -450V in the bright area (A) 'T: +T50V
A contrast potential of about 1200V was obtained.

Further, a contrast potential of about 540 ν similar to that of the comparative example was obtained by irradiating X-rays for about 0.5 seconds.

As is clear from the above results, compared to the comparative example, the photoreceptor of this example can obtain even higher contrast under almost the same charging and X-ray irradiation conditions, and on the other hand, can obtain the same contrast potential with a smaller amount of X-rays. It was done.

Furthermore, when the photoreceptor of this example was installed in a copying machine and images were evaluated, high-quality electrophotographic images with good image density and resolution were obtained.

(Example 2) A ZnS layer with a thickness of 3 μm was formed on an Al conductive substrate, and then 1100% of B element was added under the film forming conditions shown in Table 2.
Inorganic semiconductor layers having a superlattice structure consisting of a pp-containing a-5iC layer/a-Si layer were laminated to a thickness of 1 μm.

Note that this B content and the B-P content described below were both measured using a secondary ion mass spectrometer.

After that, an organic semiconductor @ (4) was formed to a thickness of 20 μm. According to its formation, hydrazone was dissolved in 1,4-dioxane solvent, and polyester resin (Refsan-LS2-11) was added in the same weight as hydrazone, ultrasonic dispersion was performed for 40 minutes, and then a bar coater was used. The coating was applied using a vacuum cleaner and then dried with hot air.

[Margin below]

Further, a polyester resin was coated to a thickness of about 15 μm on the organic semiconductor layer (4) to form a transparent insulating layer (5).

In this way, an X-ray electrophotographic photoreceptor with a negatively charged bright area potential in the reverse electric field method was produced.

Further, as a comparative example, a negatively charged photoreceptor was prepared by not forming a transparent insulating layer on the photoreceptor of this example, but using the same layer structure as that of this example.

When the photoreceptor of this comparative example was corona charged at 6 kV based on the Carlson method, it showed a charge of -630 ν. Next, the photoreceptor was irradiated with X-rays of -100 kVp and 20 mA for about 1 second, and its surface potential was measured, and it was found to be -6
The voltage decreased to 0V, and a contrast potential of about 570V was obtained.

Next, while exposing the entire surface of the photoreceptor in this example to white light,
When charging was performed using a corona charger applying a voltage of V, it showed a charge of +920V. -6kV (
7) We irradiated X-rays at 100 kVP and 20 mA for about 1 second while performing co-charging, and then exposed the entire surface of the photoreceptor to white light to measure the surface potential. The result was +430 V in the dark area (b). It becomes -770v in light part (a), and it is 1200v.
A contrast potential of V was obtained. Further, a contrast potential of 570 V similar to that of the comparative example was obtained by approximately 0.5 seconds of X-ray irradiation.

As described above, compared to the comparative example, the photoreceptor of this example obtained a high contrast potential under substantially the same charging and XvA irradiation conditions, and also obtained the same contrast potential with a smaller amount of X-rays.

Similarly to (Example 1), a high quality electrophotographic photoreceptor with good image density and resolution was obtained.

(Example 3) In this example, a photoreceptor having the embodiment shown in FIG. 2 was produced.

First, an X-ray phosphor layer (2) made of ZnS was formed to a thickness of 3 .mu.m on a transparent soda glass substrate (6) in the same manner as in Example 1. However, the A1 element was not added to the nuclear layer (2),
An appropriate amount of Cu element was added using the β-diketonate compound Cu (C, H, 0□)2.

Next, an ITO film was formed as a transparent conductive layer (7) to a thickness of 1000 nm by electron beam evaporation.

Further, on the above layer (7), based on the film forming conditions in Table 3, a
An inorganic semiconductor layer (3) having a superlattice structure consisting of -5iC layer/a-SiN layer was formed to have a thickness of 1μ.

[Margin below]

After that, an organic semiconductor layer (4) and a transparent insulating layer (5) having the same composition as in (Example 1) were formed with a thickness of 20 μm and 15 μm, respectively, so that the bright area potential in the reverse electric field method became positively charged type X. A photoreceptor for line electrophotography was produced.

Further, as a comparative example, a positively charged photoreceptor was prepared by not forming a transparent insulating layer on the photoreceptor of this example, but using the same layer structure as that of this example.

+6k on the photoreceptor of this comparative example based on the Carlson method.
When corona charging of V was performed, it showed a charge of +660V. Next, apply 100kVp and 20mA to the photoreceptor.
When X-rays were irradiated for about 1 hour and the surface potential was measured, it decreased to +60V, and a contrast potential of about 600V was obtained.

Next, the entire surface of the photoreceptor of this example was charged with a corona charger applying a voltage of -6 to ν while exposing the entire surface to white light, and a charge of -980V was obtained. While applying +6kV corona charging to this, 100kVp, 20mA Xv
A was irradiated for about 1 second, and then the entire surface of the photoreceptor was exposed to white light to measure the surface potential.
500v, +780v in the light part (A), 1280V
A contrast potential of In addition, the same 6
A contrast potential of 00■ was obtained by approximately 0.5 seconds of X-ray irradiation.

As described above, compared to the comparative example, the photoreceptor of this example obtained a higher contrast potential under substantially the same charging and X-ray irradiation conditions, and also obtained the same contrast potential with a smaller amount of X-rays.

Similarly to (Example 1), a high quality electrophotographic photoreceptor with good image density and resolution was obtained.

(Example 4) In this example, a photoreceptor of the third embodiment was produced.

First, an ITO film, which is a transparent conductive layer, is deposited on one main surface of a transparent soda glass substrate (8) by an electron beam one-layer method.
On the other main surface, an X-ray phosphor layer (2) made of ZnS was formed to a thickness of 3 μm in the same manner as in Example 1. However, the ^1 element was not added to the core layer (2), and only an appropriate amount of the Cu element was added.

Next, on top of the above ITO film is the same inorganic semiconductor layer as (Example 2) (
3) was formed by RF plasma CVD method.

After that, an organic semiconductor layer (4) and a transparent insulating layer (5) having the same composition as in (Example 1) are formed with a thickness of 20 μI and 15 μm, respectively, so that the bright area potential in the reverse electric field method becomes negatively charged type XvA. A photoreceptor for electrophotography was produced.

In addition, as a comparative example, a negatively charged photoreceptor was prepared by not forming a transparent insulating layer on the photoreceptor of this example, but with the other layer configurations being exactly the same as in this example.

When the photoreceptor of this comparative example was corona charged at 6 kV based on the Carlson method, it showed a charge of -650 V. Next, the photoreceptor was irradiated with X-rays of 10 kVp and 20 mA for about 1 second, and its surface potential was measured, and it was found to be -7
The voltage decreased to 0V, and a contrast potential of about 580V was obtained.

Next, while exposing the entire surface of the photoreceptor in this example to white light,
When charging was performed using a corona charger applying a voltage of V, it showed a charge of +930V. This knee 6kV (
7): 100kVP, 20m while performing 10S charging
When the surface potential was measured by irradiating the X-ray A for about 1 second and then exposing the entire surface of the photoreceptor to white light, it was +450V in the dark area (B) and 760V in the bright area (A), 1
A contrast potential of 210V was obtained. Further, a contrast potential of 570 V similar to that of the comparative example was obtained by approximately 0.5 seconds of X-ray irradiation.

As described above, compared to the comparative example, the photoreceptor of this example obtained a higher contrast potential under substantially the same charging and X-ray irradiation conditions, and also obtained the same contrast potential with a smaller amount of X-rays.

Similarly to (Example 1), a high quality electrophotographic photoreceptor with good image density and resolution was obtained.

(Example 5) A ZnS layer as an x'm phosphor layer and an a-SiC layer as a photocarrier excitation layer are alternately laminated on two substrates to a thickness of 100 μm each, and an inorganic semiconductor layer with a thickness of 1 μm is formed. Formed.

Dimethylzinc Zn (CH3) is used as the raw material gas for the ZnS layer.
z and hydrogen sulfide Has, and the β-diketonate compound Cu(C5H,0□)2 and triethylaluminum A1(C2)1. t) Add 3 and add copper (Cu)
A ZnS layer containing an appropriate amount of aluminum (AI) and aluminum (AI) was formed.

In addition, 5IFI4. C
2H4 and H2 gases were used.

When the two layers are alternately laminated, both are performed using a glow discharge plasma CVD apparatus by switching the introduction of the raw material gas and turning the applied high-frequency power ON and OFF.

Next, an organic semiconductor layer is formed to a thickness of 20 μm in the same manner as in (Example 1).

Thereafter, a polyester resin was coated to a thickness of about 15 μm on the organic semiconductor layer to form a transparent insulating layer.

In this way, an X-ray electrophotographic photoreceptor in which the bright area potential in the reverse electric field method was positively charged was fabricated.

In addition, as a comparative example, a positively charged photoreceptor was prepared by not forming a transparent insulating layer on the photoreceptor of this example and using the same layer structure as that of this example.

When the photoreceptor of the comparative example was corona charged to +6 kV based on the Carlson method, it showed a charge of +700 V. Next, the photoreceptor was irradiated with 2001AOX rays at 100kVp for about 1 second, and its surface potential was measured and found to be +7
The voltage decreased to 0V, and a contrast potential of about 630V was obtained.

Next, while exposing the entire surface of the photoreceptor in this example to white light,
When charging was performed using a corona charger applying a voltage of V, it showed a charge of about -1100V, and while applying +6kV corona charging, it was irradiated with X-rays at 100kV and 20mA for about 1 second, and then When the entire surface of the photoreceptor was exposed to white light and the surface potential was measured, it was -600V in the dark area (B) and +800V in the bright area (A), about 140V.
A contrast potential of 0v was obtained. Further, a contrast potential of about 630 V, similar to that of the comparative example, was obtained by irradiating X-rays for about 0.5 seconds.

As is clear from the above results, compared to the comparative example, the photoreceptor of this example can obtain even higher contrast under almost the same charging and X-ray irradiation conditions, and on the other hand, can obtain the same contrast potential with a smaller amount of X-rays. It was done.

Furthermore, when the photoreceptor of this example was installed in a copying machine and images were evaluated, high-quality electrophotographic images with good image density and resolution were obtained.

(Example 6) In this example, when producing the photoreceptor of (Example 5), B2H & gas was added to the raw material gas for the a-SiC layer, so that the B content was 200% for both elements (Si + C).
ppm, and an organic semiconductor layer with a thickness of 20 μm was formed in the same manner as in (Example 2),
Other than that, the layer configuration was the same as in (Example 5).

In this way, an X-ray electrophotographic photoreceptor with a negatively charged bright area potential in the reverse electric field method was produced.

Further, as a comparative example, a negatively charged photoreceptor was prepared by not forming a transparent insulating layer on the photoreceptor of this example, but using the same layer structure as that of this example.

Based on the Carlson method, the photoreceptor of this comparative example had a value of -6.
When corona charging was carried out, the photoreceptor showed a charge of -650 V. When the photoreceptor was irradiated with X-rays of -100 kVp and 20 mA for about 1 second and its surface potential was measured, -
The voltage was reduced to 50V, and a contrast potential of approximately 600V was obtained.

Next, while exposing the entire surface of the photoreceptor in this example to white light,
When charging was performed using a corona charger applying a voltage of V, it showed a charge of +105V. This was irradiated with X-rays of 100 kVP and 20 mA for about 1 second while performing corona charging at knee 6 kV, and then the entire surface of the photoreceptor was exposed to white light to measure the surface potential.
Te +570V, light part (I) Chi becomes 780V, 13
A contrast potential of 50V was obtained. Further, a contrast potential of 600 V similar to that of the comparative example was obtained by irradiating X-rays for about 0.5 seconds.

As described above, compared to the comparative example, the photoreceptor of this example obtained a higher contrast potential under substantially the same charging and X-ray irradiation conditions, and also obtained the same contrast potential with less xvAI.

A high-quality electrophotographic photoreceptor with good image density and resolution was obtained.

(Example 7) In this example, when producing the photoreceptor of (Example 5), PE1. gas is added, which increases the P content to 110 for both elements (Si+C).
An a-SiC layer containing 0 pp was formed, and the other layer configurations were the same as in Example 5.

In this way, an X-ray electrophotographic photoreceptor in which the bright area potential in the reverse electric field method was positively charged was fabricated.

In addition, as a comparative example, a positively charged photoreceptor was prepared by not forming a transparent insulating layer on the photoreceptor of this example and using the same layer structure as that of this example.

When the photoreceptor of the comparative example was corona charged to +6 kV based on the Carlson method, it showed a charge of +670V. Next, the photoreceptor is 100kVp, 20mA (7) Xi
was irradiated for about 1 second and the surface potential was measured, +
30V, and a contrast potential of about 640V was obtained.

Next, while exposing the entire surface of the photoreceptor in this example to white light,
When charging was performed using a corona charger applying a voltage of V, it showed a charge of about -1080V, and while corona charging of +6kV was applied to this, the charge was increased to 100kV.

Irradiation with 20mA X-rays was performed for about 1 second, followed by exposure of the entire surface of the photoreceptor to white light, and the surface potential was measured; it was -580V in the dark area (B) and +850V in the bright area (A). A contrast potential of about 1430V was obtained. Further, a contrast potential of about 640 V, similar to that of the comparative example, was obtained by irradiating X-rays for about 0.5 seconds.

As is clear from the above results, compared to the comparative example, the photoreceptor of this example can obtain even higher contrast under almost the same charging and X-ray irradiation conditions, and on the other hand, can obtain the same contrast potential with a smaller amount of X-rays. It was done.

Furthermore, when the photoreceptor of this example was installed in a copying machine and images were evaluated, high-quality electrophotographic images with good image density and resolution were obtained.

〔Effect of the invention〕

As described above, according to the X-ray electrophotographic photoreceptor of the present invention,
We use an inorganic semiconductor layer that is more sensitive to visible light at shorter wavelengths than the conventional Se layer, which allows us to obtain high sensitivity to X-rays. It was possible to increase the contrast of the latent image.

[Brief explanation of drawings]

1 to 4 are all of the present invention X1lii! FIG. 2 is a cross-sectional view showing the layer structure of a photoreceptor for secondary photography. In addition, Fig. 5 (A
) (B) (C) (D) (E) are process diagrams showing the process of the reverse electric field method, and FIG. 6 is a schematic diagram of the glow discharge decomposition apparatus. X-ray phosphor layer...Inorganic semiconductor layer Organic semiconductor layer Transparent conductive layer

Claims (4)

[Claims] (1) An X-ray phosphor layer, an amorphous silicon layer, and an amorphous silicon carbide layer whose compositional formula Si_1_-_XC_X has an X value of 0<X<0.5 are stacked so that their optical band gaps differ from each other. An X-ray electrophotography characterized in that an inorganic semiconductor layer and an organic semiconductor layer each having a thickness of 20 to 500 Å are sequentially laminated on a conductive substrate, and a transparent insulating layer is laminated on the organic semiconductor layer. Photoreceptor for use. (2) The X value of the X-ray phosphor layer, transparent conductive layer, amorphous silicon layer and compositional formula Si_1_-_XC_X is 0<X<
Amorphous silicon carbide layers represented by 0.5 are laminated so that their optical band gaps differ from each other, and an inorganic semiconductor layer and an organic semiconductor layer each having a thickness of 20 to 500 Å are sequentially laminated on a substrate, A photoreceptor for X-ray electrophotography, characterized in that a transparent insulating layer is laminated on the organic semiconductor layer. (3) An X-ray phosphor layer is formed on one main surface of a transparent substrate, and at least the other main surface is electrically conductive, and an amorphous silicon layer and a composition formula Si_1_- are formed on the electrically conductive main surface.
Amorphous silicon carbide layers with an X value of _XC_X of 0<X<0.5 are stacked so that their optical band gaps are different from each other, and each layer has a thickness of 20 to 500 mm.
1. A photoreceptor for X-ray electrophotography, characterized in that an inorganic semiconductor layer and an organic semiconductor layer are sequentially laminated, and a transparent insulating layer is laminated on the organic semiconductor layer. (4) An X-ray phosphor layer and an amorphous silicon carbide layer whose compositional formula Si_1_-_XC_X has an X value of 0<X<0.5 are laminated, and each layer has a thickness of 50 to 2000.
1. A photoreceptor for X-ray electrophotography, characterized in that an inorganic semiconductor layer and an organic semiconductor layer of .