JP2008078597A - Radiographic image detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent crystallization at the interface with a lower layer and at the interface with an upper layer, to improve the electron transit properties, and to prevent the increase in image failures occurring with the passage of time, with reference to a radiographic image detector. <P>SOLUTION: This radiographic image detector comprises a first electrode 1 that an electromagnetic wave for recording carrying radiographic images penetrates, a photoconductive layer for recording 3 made of amorphous selenium containing alkali metal as a principal component, where electrical charges are generated by irradiation of the electromagnetic wave for recording that has penetrated the first electrode 1, a plurality of charge collection electrodes 4, and a substrate 5, which are laminated in the above sequence. In the radiographic image detector, between the first electrode 2 and the photoconductive layer for recording 3, an amorphous selenium layer that contains 5% to 40% of at least one element chosen from a group consisting of As, Sb and Bi is provided, as a crystallization prevention layer 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a radiation image detector capable of recording image information as an electrostatic charge pattern (electrostatic latent image) formed by irradiation with radiation such as X-rays.

  Conventionally, in medical X-ray photography, a photoconductive layer sensitive to X-rays has been used as a photoconductor to reduce the exposure dose received by subjects and improve diagnostic performance. A radiation image detector that reads and records the electrostatic latent image formed by light or multiple electrodes is known. These are superior in that the resolution is higher than the indirect photographing method using a TV image pickup tube which is a well-known photographing method.

  The radiation image detector described above generates charges corresponding to X-ray energy by irradiating the charge generation layer provided in the radiation image detector with X-rays, and reads the generated charges as an electrical signal. The photoconductive layer functions as a charge generation layer. Conventionally, amorphous selenium (a-Se) has been used as the photoconductive layer.

  The amorphous selenium can easily cope with an increase in area by using a thin film forming technique such as a vacuum deposition method, but has a tendency to include many structural defects, so that sensitivity is likely to deteriorate. Therefore, in order to improve the performance, it is a common practice to add (doping) an appropriate amount of impurities.

  For example, Patent Document 1 describes that an a-Se or a-Se: As alloy is doped with 5 to 5000 ppm of alkali metal to form a good photoconductive layer in which both electrons and holes travel. Has been. However, if Na is doped to 0.01 ppm or more in a-Se, interface crystallization is likely to occur at the contact interface with the electrode, and image defects are likely to occur, and characteristics are likely to change due to humidity, resulting in durability. There is a problem that it is difficult. The problem that the a-Se containing the alkali metal is easily crystallized at the interface is that the Na amount at the interface is 0.01 ppm even when the Na doping amount in the bulk of the a-Se is less than 0.01 ppm. This is the case. In particular, when the electrode substrate is a substrate in which a large number of switching elements (TFTs) and pixel electrodes are arranged two-dimensionally, or a substrate in which a large number of linear electrodes for reading are arranged, the electrodes are finely patterned. Since there is a step, crystallization is likely to occur at the electrode step portion. In addition, when an upper electrode for applying a bias electric field is provided on the photoconductive layer, crystallization is likely to occur immediately below the upper electrode due to thermal radiation damage during film formation of the upper electrode.

In Patent Document 2, in order to suppress sensitivity deterioration, 0.01 to 10 ppm of alkali metal is doped into a-Se, and in order to suppress dark current, between the lower electrode (TFT) and the a-Se layer, A configuration is described in which a lower carrier selection layer such as AsSe or Sb ₂ S ₃ is provided, and an upper carrier selection layer such as CdS or Sb ₂ S ₃ is provided between the upper electrode and the a-Se layer. In this configuration, the recording photoconductive layer mainly composed of a-Se containing an alkali metal is provided on the lower carrier selection layer which is a different material not containing Se as a main component. Further, stress is easily applied to the joint surface due to a difference in coefficient of thermal expansion, and Se crystallization is likely to occur at the interface. In addition, since the upper carrier selection layer, which is a different material not containing Se as a main component, is provided on the recording photoconductive layer mainly containing a-Se containing an alkali metal, the difference in lattice constants, the coefficient of thermal expansion, and the like. Due to the difference in the rate and the like, stress is easily applied to the joint surface, and thermal radiation damage is applied when forming the upper carrier selection layer, so that crystallization at the interface is likely to occur.

  Also, in Patent Document 3, a 200-800 μm thick a-Se added with 0.1 to 1% arsenic and 20-200 ppm alkali metal doped a-Se as a carrier selection layer are laminated. Then, 0.1 to 1% of As is added to the interface between the carrier selection layer and the electrode in order to suppress the dark current by using the recording photoconductive layer mainly containing a-Se containing an alkali metal. It is described that the dark current can be reduced by inserting the formed Se layer.

  Also, in Patent Document 4, a dark current is reduced between an upper electrode and an a-Se photoconductive layer doped with As and Cl having a thickness of between 100 μm and 2 mm. It is described that a-Se doped with 1 to 1000 ppm of alkali is laminated as a monopolar conductive layer. This monopolar conductive layer may contain 0.5 to 5 wt% of As at the same time. However, As cannot be impaired as the monopolar conductive layer, As cannot be contained more than 5 wt%. Moreover, the thickness of the monopolar conductive layer is required to be 0.5 to 10 μm in order to capture the injected charge.

Further, the same patent document 4 discloses that an a-Se photoconductive layer doped with As and Cl having a thickness of between 100 μm and 2 mm and a lower electrode are provided as an interrupt buffer layer. It is described that an As ₂ Se ₃ layer is provided. This interrupt buffer layer is provided to promote electron blocking properties and adhesion with the glass substrate, and requires a film thickness of 0.5 to 10 μm. It is also described that the interrupt buffer layer prevents crystallization at the interface with a-Se doped with As and Cl.
US Pat. No. 3,658,989 JP 2003-315464 A JP-A-6-209097 JP-A-10-104358

  However, the photoconductive layer doped with alkali metal in Se as described in each of the above documents is a lower layer (if there is a lower carrier selection layer made of a different material not containing Se as a main component, lower carrier selection) Means a lower electrode when there is no lower carrier selection layer, hereinafter referred to as a lower electrode, an upper layer (an upper carrier selection layer made of a different material not containing Se as a main component) In some cases, it means an upper carrier selection layer, and in the absence of the upper carrier selection layer, it means an upper electrode (hereinafter referred to as an upper layer). It is impossible to suppress a decrease in durability.

Further, in the configuration described in Patent Document 2, since the mask sizes of the carrier selection layer and the a-Se layer are different, a mask replacement time is generated, and since this time is long, the carrier selection layer and the a-Se There is a problem that impurities (for example, H ₂ O and oxygen) that promote crystallization are mixed between Se layers. The crystallization of the interface cannot be reduced by providing a Se layer added with 0.1 to 1% As at the interface between the carrier selection layer and the electrode as described in Patent Document 3, and Also, image defects cannot be reduced.

Further, the crystallization of the interface is reduced by the method of adding 0.5 to 5 wt% As in the bulk of the alkali-doped a-Se monopolar conductive layer as described in Patent Document 4. And image defects cannot be reduced. Further, the interrupt buffer layer composed of the a-As ₂ Se ₃ layer described in Patent Document 4 has a problem in that the resolution of the holes tends to deteriorate due to large diffusion of holes transferred from the recording photoconductive layer. In addition, the a-As ₂ Se ₃ layer has no description regarding crystallization at the interface with the layer made of a-Se containing an alkali metal.

Further, the use of the Sb ₂ S ₃ in Patent Document 2 as a lower carrier selection layer, Sb ₂ S ₃ is the resolution is not degraded hampered diffusion of charge for a semi-insulating (JP 2001-284628 see However, there is a problem that the interface between the lower layer made of Sb ₂ S ₃ and the recording photoconductive layer made of a-Se containing an alkali metal tends to be crystallized, which is incompatible.

  The present invention has been made in view of the above circumstances, and solves the problem of crystallization at the interface between the photoconductive layer containing an alkali metal and containing a-Se as a main component and the lower layer and the interface with the upper layer. An object of the present invention is to provide a radiological image detector capable of improving the electronic running property and suppressing an increase in image defects over time.

  As a first aspect, the radiation image detector of the present invention includes a first electrode that transmits a recording electromagnetic wave carrying a radiation image, and charges by irradiation of the recording electromagnetic wave that has passed through the first electrode. In the radiation image detector formed by laminating a generated photoconductive layer mainly composed of amorphous selenium containing alkali metal, a plurality of charge collecting electrodes, and a substrate in this order, the first electrode and the An amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb and Bi is provided as an anti-crystallization layer between the recording photoconductive layer. To do.

The content of the above element is% by weight, and the recording photoconductive layer containing amorphous selenium as a main component means the one having the highest weight% component of amorphous selenium among the components of the recording photoconductive layer (hereinafter, The same applies to the radiation image detector according to another aspect of the present invention).
The film thickness of the anti-crystallization layer is preferably 0.05 μm to 0.3 μm.

  As another aspect of the first radiographic image detector, the radiographic image detector of the present invention transmits a first electrode that transmits a recording electromagnetic wave carrying a radiographic image, and transmits the first electrode. Radiation image detection formed by laminating a recording photoconductive layer mainly composed of amorphous selenium containing alkali metal, a plurality of charge collecting electrodes, and a substrate, which generate charges by irradiation of the recording electromagnetic wave. And an amorphous selenium layer containing at least one element selected from the group consisting of As, Sb, and Bi as an anti-crystallization layer between the first electrode and the recording photoconductive layer. The crystallization preventing layer includes at least a region where the element concentration has a maximum value and a region where the element concentration has a concentration of 80% or less of the maximum value concentration. The element concentration in a region where the element concentration takes a maximum value is preferably 5% to 40%.

  The element concentration in the anti-crystallization layer is within the region of 50 nm interface with the upper layer not containing selenium as a main component located on the opposite side of the anti-crystallization layer from the photoconductive layer for recording. It is preferable to take the maximum value.

  Alternatively, the element concentration in the anti-crystallization layer may take a maximum value within a region of 50 nm interface with the recording photoconductive layer.

  Furthermore, the upper layer side region of the interface 50 nm with the upper layer not containing selenium as a main component located on the opposite side of the recording photoconductive layer with respect to the anti-crystallization layer in the anti-crystallization layer, and In the crystallization prevention layer, the average concentration of the element in the crystallization prevention layer other than the recording photoconductive layer side region at the interface of 50 nm with the recording photoconductive layer is the lower one in the upper layer side region. It may be 80% or less of the concentration.

  The upper layer that does not contain selenium as a main component means that the weight percentage component of amorphous selenium is not the highest among the components of the upper layer, and the upper layer means that the radiation image detector does not contain amorphous selenium as the main component. In the case of having an upper carrier selection layer made of a different material, it means the upper carrier selection layer, and in the absence of the upper carrier selection layer, it means the first electrode.

  The average concentration of the element means an average concentration calculated by adding the weight percent of each element when there are two or more elements selected from the group consisting of As, Sb, and Bi (hereinafter referred to as “the average concentration”). Mean concentration means this).

As a second aspect, the radiation image detector of the present invention includes a first electrode that transmits a recording electromagnetic wave carrying a radiation image, and charges by irradiation of the recording electromagnetic wave that has passed through the first electrode. In the radiation image detector formed by laminating the generated photoconductive layer mainly composed of amorphous selenium containing alkali metal, a plurality of charge collection electrodes, and a substrate in this order, the charge collection electrode and the recording An amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb and Bi is provided as an anti-crystallization layer between the photoconductive layer for use. Is.
The film thickness of the anti-crystallization layer is preferably 0.05 μm to 0.3 μm.

  As another aspect of the second radiological image detector, the radiographic image detector of the present invention transmits a first electrode that transmits a recording electromagnetic wave carrying a radiographic image, and transmits the first electrode. Radiation image detection formed by laminating a recording photoconductive layer mainly composed of amorphous selenium containing alkali metal, a plurality of charge collecting electrodes, and a substrate, which generate charges by irradiation of the recording electromagnetic wave. And an amorphous selenium layer containing at least one element selected from the group consisting of As, Sb, and Bi as an anti-crystallization layer between the charge collection electrode and the recording photoconductive layer, The crystallization preventing layer includes at least a region where the element concentration has a maximum value and a region where the element concentration has a concentration of 80% or less of the maximum value. The element concentration in a region where the element concentration takes a maximum value is preferably 5% to 40%.

  The element concentration in the anti-crystallization layer is within a region of 50 nm interface with the lower layer containing as a main component amorphous selenium located on the opposite side of the anti-crystallization layer from the photoconductive layer for recording. It is preferable to take the maximum value.

  Alternatively, the element concentration in the anti-crystallization layer may take a maximum value within a region of 50 nm interface with the recording photoconductive layer.

  Furthermore, the lower layer side region of the interface 50 nm with the lower layer not containing amorphous selenium as a main component located on the opposite side of the recording photoconductive layer with respect to the anti-crystallization layer in the anti-crystallization layer, and The average concentration of the element in the crystallization preventing layer other than the recording photoconductive layer side region at the interface with the recording photoconductive layer in the crystallization preventing layer in the 50 nm interface is the element concentration in the lower layer side region. 80% or less of the smaller one of the maximum value and the maximum value of the element concentration in the recording photoconductive layer side region.

  The lower layer that does not contain selenium as the main component means that the weight percentage component of amorphous selenium is not the highest among the components of the lower layer, and the lower layer does not contain the amorphous selenium as the main component. When it has a lower carrier selection layer made of a different material, it means a lower carrier selection layer, and when there is no lower carrier selection layer, it means a first electrode.

The lower layer is preferably a semi-insulator layer. The semi-insulator layer is a charge transport layer made of a semi-insulator having a specific resistance value of 10 ⁶ Ω · cm or more and 10 ¹² Ω · cm or less. The junction with the layer (a-Se) has a diode characteristic in which the charge transport layer is a cathode and the recording photoconductive layer (a-Se) is an anode. Preferred examples of the semi-insulator layer include antimony sulfide (Sb ₂ S ₃ ) and arsenic sulfide (As ₂ S ₃ ). Hereinafter, the semi-insulator layer has this meaning.

As a third aspect, the radiation image detector of the present invention includes a first electrode that transmits a recording electromagnetic wave carrying a radiation image, and charges by irradiation of the recording electromagnetic wave that has passed through the first electrode. A photoconductive layer for recording mainly composed of amorphous selenium containing alkali metal, a power storage unit for accumulating charges generated in the photoconductive layer for recording, and reading light for generating charges by irradiation of reading light In a radiation image detector in which a conductive layer, a number of linear electrodes for reading, and a substrate are laminated in this order, a crystallization-preventing layer is provided between the first electrode and the recording photoconductive layer. As a characteristic feature, an amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb, and Bi is provided.
The film thickness of the anti-crystallization layer is preferably 0.05 μm to 0.3 μm.

  As another aspect of the third radiological image detector, the radiological image detector of the present invention transmits a first electrode that transmits a recording electromagnetic wave carrying a radiographic image, and transmits the first electrode. A recording photoconductive layer mainly composed of amorphous selenium containing an alkali metal, which generates a charge when irradiated with the recording electromagnetic wave, a power storage unit for accumulating the charge generated in the recording photoconductive layer, and reading light In the radiographic image detector in which a reading photoconductive layer that generates an electric charge by irradiation, a number of linear electrodes for reading, and a substrate are laminated in this order, the first electrode and the recording photoconductive layer Between the layers, there is an amorphous selenium layer containing at least one element selected from the group consisting of As, Sb, and Bi as an anti-crystallization layer, and the anti-crystallization layer has at least the highest element concentration. The value A region that, the element concentration is characterized in that including the region to take 80% or less of the concentration of the concentration of said maximum value. The element concentration in a region where the element concentration takes a maximum value is preferably 5% to 40%.

  The element concentration in the anti-crystallization layer is within a region of 50 nm interface with the upper layer containing as a main component amorphous selenium located on the opposite side of the anti-crystallization layer from the photoconductive layer for recording. It is preferable to take the maximum value.

  Alternatively, the element concentration in the anti-crystallization layer may take a maximum value within a region of 50 nm interface with the recording photoconductive layer.

  Further, an upper layer side region having an interface of 50 nm with an upper layer containing as a main component amorphous selenium located on the opposite side of the recording photoconductive layer with respect to the anti-crystallization layer in the anti-crystallization layer, and The average concentration of the element in the crystallization prevention layer other than the recording photoconductive layer side region at the interface of 50 nm with the recording photoconductive layer in the crystallization prevention layer is the element concentration in the upper layer side region. 80% or less of the smaller one of the maximum value and the maximum value of the element concentration in the recording photoconductive layer side region.

  The upper layer that does not contain selenium as the main component means that the weight percentage component of amorphous selenium is not the highest in the components of the upper layer, and the upper layer does not contain amorphous selenium as the main component in the radiographic image detector. In the case of having an upper carrier selection layer made of a different material, it means the upper carrier selection layer, and in the absence of the upper carrier selection layer, it means the first electrode.

As a fourth aspect, the radiological image detector of the present invention includes a first electrode that transmits a recording electromagnetic wave carrying a radiographic image, and charges due to irradiation of the recording electromagnetic wave that has passed through the first electrode. A photoconductive layer for recording, a power storage unit for accumulating charges generated in the photoconductive layer for recording, and a read light mainly composed of amorphous selenium containing an alkali metal that generates charges when irradiated with read light In a radiation image detector in which a conductive layer, a number of linear electrodes for reading, and a substrate are stacked in this order, a crystallization-preventing layer is provided between the linear electrode and the reading photoconductive layer. An amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb, and Bi is provided.
Furthermore, the film thickness of the anti-crystallization layer is preferably 0.05 μm to 0.3 μm.

  As another aspect of the fourth radiation image detector, the radiation image detector of the present invention includes a first electrode that transmits a recording electromagnetic wave carrying a radiation image, and the recording that transmits the first electrode. A recording photoconductive layer that generates charges when irradiated with electromagnetic waves, a power storage unit that stores charges generated in the recording photoconductive layer, and amorphous selenium containing an alkali metal that generates charges when irradiated with reading light. In a radiation image detector in which a reading photoconductive layer as a main component, a number of linear electrodes for reading, and a substrate are laminated in this order, between the linear electrode and the reading photoconductive layer And an amorphous selenium layer containing at least one element selected from the group consisting of As, Sb, and Bi as the anti-crystallization layer, and the anti-crystallization layer has at least the region where the element concentration takes a maximum value. When It is characterized in that the element concentration and a region that takes 80% or less of the concentration of the concentration of said maximum value. The element concentration in a region where the element concentration takes a maximum value is preferably 5% to 40%.

  The element concentration in the anti-crystallization layer is within the region of 50 nm interface with the lower layer containing as a main component amorphous selenium located on the opposite side of the read photoconductive layer with respect to the anti-crystallization layer. It is preferable to take the maximum value.

  Alternatively, the element concentration in the anti-crystallization layer may take a maximum value within a region of 50 nm interface with the reading photoconductive layer.

  Furthermore, the lower layer side region of the interface 50 nm with the lower layer not containing amorphous selenium as a main component located on the opposite side of the reading photoconductive layer with respect to the anti-crystallization layer in the anti-crystallization layer, and The average concentration of the element in the crystallization preventing layer other than the reading photoconductive layer side region at the interface of 50 nm with the reading photoconductive layer in the crystallization preventing layer is the element concentration in the lower layer side region. 80% or less of the smaller one of the maximum value and the maximum value of the element concentration in the reading photoconductive layer side region.

The lower layer that does not contain selenium as the main component means that the weight percentage component of amorphous selenium is not the highest among the components of the lower layer, and the lower layer does not contain the amorphous selenium as the main component. When it has a lower carrier selection layer made of a different material, it means a lower carrier selection layer, and when there is no lower carrier selection layer, it means a linear electrode.
The lower layer is preferably a semi-insulator layer.

  In the radiographic image detector of the present invention, the photoconductive layer mainly composed of amorphous selenium containing alkali metal is not limited to the case where alkali metal is included in the film at a uniform concentration, but is described in Patent Document 3. As described above, the bulk does not contain an alkali metal, and at least one of the interfaces is provided with a region made of amorphous selenium containing an alkali metal, and may be a photoconductive layer made of amorphous selenium containing an alkali metal as a whole. Is included.

  The content of the alkali metal in the radiation image detector of the present invention is preferably 0.01 to 5000 ppm.

  The radiation image detector according to the first aspect of the present invention includes a first electrode that transmits a recording electromagnetic wave carrying a radiation image, and charges by irradiation of the recording electromagnetic wave transmitted through the first electrode. In a radiation image detector in which a generated photoconductive layer mainly composed of amorphous selenium containing alkali metal, a plurality of charge collection electrodes, and a substrate are laminated in this order, the first electrode and the recording Since an amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb, and Bi is provided as an anti-crystallization layer between the photoconductive layer and the photoconductive layer for recording. Interfacial crystallization that occurs when the upper layer is formed on the layer can be prevented, and the image quality can be improved. Furthermore, performance degradation such as crystallization due to humidity can be prevented. Furthermore, if the film thickness of the anti-crystallization layer is 0.05 to 0.3 μm, it is possible to prevent the dark current from deteriorating while preventing the interface from being crystallized.

  The radiation image detector according to the second aspect of the present invention includes a first electrode that transmits a recording electromagnetic wave carrying a radiation image, and charges by irradiation of the recording electromagnetic wave that has passed through the first electrode. In a radiation image detector in which a recording photoconductive layer mainly composed of amorphous selenium containing alkali metal, a plurality of charge collection electrodes, and a substrate are laminated in this order, the charge collection electrode and the recording light An amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb, and Bi is provided as an anti-crystallization layer between the conductive layer and the photoconductive layer for recording. Interfacial crystallization that occurs when the layer is provided on the lower layer can be prevented, and the image quality can be improved. Furthermore, performance degradation such as crystallization due to humidity can be prevented. Furthermore, if the film thickness of the anti-crystallization layer is 0.05 to 0.3 μm, it is possible to prevent the dark current from deteriorating while preventing the interface from being crystallized. Furthermore, if the lower layer is a semi-insulator layer, the diffusion of carriers that have moved into the lower layer, which is a semi-insulator layer, is prevented while preventing the crystallization of the interface, thereby suppressing degradation of resolution. can do.

  The radiographic image detector according to the third aspect of the present invention includes a first electrode that transmits a recording electromagnetic wave carrying a radiographic image, and charges by irradiation of the recording electromagnetic wave transmitted through the first electrode. A photoconductive layer for recording mainly composed of amorphous selenium containing alkali metal, a power storage unit for accumulating charges generated in the photoconductive layer for recording, and reading light for generating charges by irradiation of reading light In a radiation image detector in which a conductive layer, a number of linear electrodes for reading, and a substrate are laminated in this order, As is provided as an anti-crystallization layer between the first electrode and the recording photoconductive layer. Is generated when an upper layer is formed on the photoconductive layer for recording because an amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of Sb, Bi is provided. Prevents interface crystallization It can be, it is possible to increase the quality of the image. Furthermore, performance degradation such as crystallization due to humidity can be prevented. Furthermore, if the film thickness of the anti-crystallization layer is 0.05 to 0.3 μm, it is possible to prevent the dark current from deteriorating while preventing the interface from being crystallized.

  According to a fourth aspect of the present invention, there is provided a radiographic image detector comprising: a first electrode that transmits a recording electromagnetic wave carrying a radiographic image; and a charge generated by irradiation of the recording electromagnetic wave transmitted through the first electrode. A recording photoconductive layer that is generated, a power storage unit that accumulates charges generated in the recording photoconductive layer, and a reading light mainly composed of amorphous selenium containing an alkali metal that generates charges when irradiated with reading light In a radiation image detector in which a conductive layer, a plurality of linear electrodes for reading, and a substrate are laminated in this order, As, as an anti-crystallization layer, between the linear electrodes and the reading photoconductive layer, Since an amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of Sb and Bi is provided, interfacial crystallization that occurs when the reading photoconductive layer is provided on the lower layer Can prevent Come, it is possible to increase the quality of the image. Furthermore, performance degradation such as crystallization due to humidity can be prevented. Furthermore, if the film thickness of the anti-crystallization layer is 0.05 to 0.3 μm, it is possible to prevent the dark current from deteriorating while preventing the interface from being crystallized.

  Moreover, in another aspect of the first to fourth radiological image detectors, the crystallization preventing layer includes at least a region where the element concentration has a maximum value, and the element concentration is 80% of the maximum concentration. By including a region having the following concentration, the average element concentration of the entire crystallization prevention layer can be reduced.

  The radiological image detector of the present invention stores a charge generated by radiation irradiation, even in a so-called optical reading system that reads by a radiographic image detector using a semiconductor material that generates a charge by light irradiation, A method of reading accumulated charges by turning on and off an electrical switch such as a thin film transistor (TFT) one pixel at a time (hereinafter referred to as a TFT method) may be used. The radiation image detector of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing a first embodiment of the radiation image detector (TFT method) of the present invention. As shown in FIG. 1, the radiation image detector 10 of the first aspect includes a first electrode 1 that transmits a recording electromagnetic wave carrying a radiation image, a crystallization preventing layer 2, and a first electrode 1. A recording photoconductive layer 3 mainly composed of amorphous selenium containing alkali metal, which generates charges when irradiated with a recording electromagnetic wave, a plurality of charge collecting electrodes (TFT electrodes) 4, and a substrate 5 in this order. Laminated.

  FIG. 2 is a schematic cross-sectional view showing a second embodiment of the radiation image detector (TFT method) of the present invention. As shown in FIG. 2, the radiographic image detector 10 according to the second aspect includes a first electrode 1 that transmits a recording electromagnetic wave carrying a radiographic image, and a recording electromagnetic wave that transmits the first electrode 1. A recording photoconductive layer 3 mainly composed of amorphous selenium containing an alkali metal, which generates a charge upon irradiation, a crystallization preventing layer 2 ′, a plurality of charge collecting electrodes (TFT electrodes) 4, and a substrate 5. It is laminated in order.

The crystallization preventing layer 2 shown in FIG. 1 and the crystallization preventing layer 2 ′ shown in FIG. 2 contain at least one element selected from the group consisting of As, Sb, and Bi, 5% to 40%, more preferably 7%. It is preferable that it is an a-Se layer containing ~ 40%, more preferably 10% ~ 40%. The above range is selected depending on the effect of preventing crystallization. The concentration of these specific elements can be measured by XPS (X-ray photoelectron spectroscopy). When the content ratio of at least one element selected from the group consisting of As, Sb, and Bi is less than 5%, the effect of preventing crystallization is not sufficient. When the specific element is contained at 5% or more, sufficient crystallization suppression can be achieved when the upper layer or the lower layer is a chemically stable metal such as Au or Pt. When the specific element is contained in an amount of 7% or more, crystallization at the interface is suppressed even when alkali metal is concentrated at a high concentration (1-1000 ppm) on the interface of the anti-crystallization layer on the recording photoconductive layer side. be able to. When the specific element is contained in an amount of 10% or more, alkali metal concentrates on the interface of the anti-crystallization layer on the recording photoconductive layer side (1-1000 ppm), and Sb ₂ S ₃ , Al, etc. are formed on the anti-crystallization layer. Even when an upper layer having a large influence on the amorphous state is attached, crystallization of the interface can be suppressed.

  In the case where the specific element is contained in an amount of more than 40%, the metal element is deposited, the resistance is locally reduced, and an image defect is caused, which is not preferable.

  The film thickness of the crystallization preventing layer is preferably 0.05 to 0.5 μm. More preferably, it is 0.05-0.3 micrometer. When the film thickness is less than 0.05 μm, a region where crystallization cannot be partially prevented tends to occur. On the other hand, if the film thickness is thicker than 0.5 μm, the electric characteristics are likely to deteriorate, for example, the charge trap increases and the dark current increases. If the film thickness is 0.3 μm or less, an increase in dark current can be suppressed, and charge diffusion can be suppressed to prevent deterioration of resolution.

  The concentration of the specific element is not necessarily uniform in the crystallization preventing layer, and it is sufficient that the specific element is contained in the region having the highest specific element concentration in the layer by 5% to 40%. Taking the case where the specific element is As as an example, the concentration distribution of the specific element in the crystallization prevention layer will be described in detail with reference to FIGS. 4 to 5 are schematic diagrams in which the horizontal axis represents the thickness of the upper layer, the anti-crystallization layer, and the recording photoconductive layer, and the vertical axis represents the relative concentrations of AS and Se (this specific element distribution). Since the same applies to a radiographic image detector of another aspect to be described later, this description of the radiographic image detector of another aspect will be omitted).

  As shown in FIG. 4, in the region of 50 nm interface with the upper layer in the anti-crystallization layer, if As is set to the maximum value, crystallization occurring at the contact interface with the upper layer is effectively suppressed. can do. The crystallization prevention layer has a higher crystallization suppression effect as the concentration of As (specific element) is higher. However, since the upper layer is a different material that does not contain selenium as a main component, crystallization prevention mainly contains selenium. The contact interface with the layer is likely to be stressed due to a difference in lattice constant, a difference in thermal expansion coefficient, and the like, and crystallization is particularly likely to occur. For this reason, if As is set to the maximum value in the region of the interface 50 nm with the upper layer in the crystallization preventing layer, the maximum crystallization suppressing effect can be obtained with a small amount of As added. In this case, the average concentration of As element in the region of 50 nm interface with the recording photoconductive layer in the crystallization preventing layer may be 1% or less.

  Here, the interface between the upper layer and the anti-crystallization layer means that the Se concentration in the anti-crystallization layer is 5% of the Se concentration (maximum value) of the recording photoconductive layer toward the upper layer by XPS measurement. It can be determined as the number of points reduced. Further, the interface between the anti-crystallization layer and the recording photoconductive layer can be defined as a location where the As concentration in the anti-crystallization layer is reduced to 5% of the maximum concentration toward the recording photoconductive layer ( In the present invention, the interface means this).

On the other hand, as shown in FIG. 5, the interface between the recording photoconductive layer and the crystallization preventing layer can be obtained by setting the maximum value of As in the region within 50 nm of the interface between the crystallization preventing layer and the recording photoconductive layer. Can be effectively suppressed. The recording photoconductive layer does not necessarily contain an alkali metal in the film at a uniform concentration. For example, as described in Patent Document 3, there are cases where the interface contains a large amount of alkali metal. It easily reacts with H ₂ O and the like, and crystallization is likely to occur. Therefore, if the As (specific element) takes the maximum value in the region within 50 nm of the interface between the anti-crystallization layer and the recording photoconductive layer, the maximum crystallization suppression effect can be obtained with a small amount of As added. Can do. In this case, the As average concentration in the region of 50 nm interface with the upper layer in the crystallization preventing layer may be 1% or less.

  Further, as shown in FIG. 6, the average of As in the crystallization preventing layer other than the upper layer side region at the interface 50 nm with the upper layer and the recording photoconductive layer side region at the interface 50 nm with the recording photoconductive layer. By setting the concentration to 80% or less of the smaller one of the maximum value of As concentration in the upper layer side region and the maximum value of As concentration in the recording photoconductive layer side region, that is, crystallization While increasing the concentration of both interfaces of the prevention layer, the average concentration of the other regions is selected from the maximum value of As concentration in the upper layer side region and the maximum value of As concentration in the recording photoconductive layer side region. By reducing the smaller concentration (upper layer side region in FIG. 6) to 80% or less, preferably 50% or less, the average element concentration of the entire crystallization preventing layer can be reduced. By doing in this way, the average element concentration of the whole crystallization prevention layer can also be made into 1% or less.

  As shown in FIG. 3, the anti-crystallization layer is provided both between the first electrode 2 and the recording photoconductive layer 3 and between the charge collection electrode 4 and the recording photoconductive layer 3. It may be. In this case, at least one of the crystallization prevention layers may be an amorphous selenium layer containing 5% to 40% of the specific element, but both crystallization prevention layers contain amorphous selenium containing 5% to 40% of the specific element. A layer is more preferable.

  The recording photoconductive layer is a layer mainly composed of amorphous selenium containing an alkali metal such as Na, K, Li, and the alkali metal content is preferably 0.01 to 5000 ppm. Usually, when the content of alkali metal is higher than 0.01 ppm, crystallization is likely to occur at the interface with the upper layer, and thus it is not possible to suppress an increase in image defects and a decrease in durability. Since the image detector is provided with the anti-crystallization layer as described above, it is possible to improve the quality of the image by simultaneously suppressing the crystallization while realizing the prevention of the sensitivity deterioration. An appropriate amount of arsenic may be contained in addition to the alkali metal. By containing arsenic, crystallization in the bulk of amorphous selenium can be reduced.

  The first electrode is suitably a conductive material such as Au or Al that can be deposited by resistance heating and that can suppress the influence of radiant heat to a low level. The charge collection electrode is made of a conductive material such as ITO (indium tin oxide), Au, or Pt.

  The radiation image detector can be manufactured by a known method, but it is preferable that the crystallization preventing layer and the recording photoconductive layer are continuously deposited (film formation) in the same vacuum. Moreover, the effect of preventing crystallization can be further enhanced by stacking at high speed using the same vapor deposition mask.

  Next, an optical reading type radiation image detector will be described. FIG. 7 is a schematic cross-sectional view showing a first aspect of an optical reading type radiographic image detector. As shown in FIG. 7, the radiological image detector 20 includes a first electrode 21 that transmits a recording electromagnetic wave carrying a radiographic image, a crystallization prevention layer 22, and a recording that passes through the first electrode 21. The recording photoconductive layer 23 mainly composed of amorphous selenium containing alkali metal, which generates charges when irradiated with electromagnetic waves, and the charge charged to the first electrode 21 (latent image polar charge; for example, negative charge) A charge transport layer 26 that acts as a substantially conductive material for a charge of opposite polarity to the charge (transport polar charge; positive charge in the above example), and reading light. A photoconductive layer 27 for reading that generates a charge by irradiation, a number of linear electrodes (comb electrodes) 24 for reading, and a substrate 25 are sequentially laminated.

  FIG. 8 is a schematic cross-sectional view showing a second aspect of the optical reading type radiation image detector. As shown in FIG. 8, the radiological image detector 20 includes a first electrode 21 that transmits a recording electromagnetic wave carrying a radiographic image, and charges by irradiation of the recording electromagnetic wave that transmits the first electrode 21. For the recording photoconductive layer 23 ′ and the first electrode 21 charged with a charge (latent image polar charge; for example, negative charge), and acts as an insulator and has a charge opposite in polarity to the charge. For (transport polar charge; positive charge in the above example), a charge transport layer 26 that functions as a substantially conductive material, and for reading mainly composed of amorphous selenium containing alkali metal that generates a charge when irradiated with reading light A photoconductive layer 27 ′, a crystallization preventing layer 22 ′, a number of linear electrodes (comb electrodes) 24 for reading, and a substrate 25 are laminated in order.

  The charge transport layer 26 acts as an insulator for charges having the same polarity as the charge charged on the first electrode 21, and acts as a conductor for charges having the opposite polarity to the charge. Since it is a charge transport layer, the negative charge that has moved through the recording photoconductive layer 23 stops at the interface between the recording photoconductive layer 23 and the charge transport layer 26 and is accumulated at this interface (power storage unit). Will be. When the radiation image detector does not include the charge transport layer 26, the power storage unit includes the recording photoconductive layer 23 and the reading photoconductive layer 27 (in the second embodiment, the recording photoconductive layer 23 'and the reading photoconductive layer 26). It becomes the interface of the photoconductive layer 27 ').

  The crystallization preventing layers 22 and 22 'contain 5% to 40%, more preferably 7% to 40%, and even 10% to 40% of at least one element selected from the group consisting of As, Sb, and Bi. An a-Se layer is preferred. Note that the significance of the numerical limitation of the specific element here is the same as the significance described in the crystallization prevention layers 2 and 2 ', and therefore the description is omitted. As shown in FIG. 9, the crystallization preventing layer is provided both between the first electrode 22 and the recording photoconductive layer 23 and between the linear electrode 24 and the reading photoconductive layer 27 '. It may be done. In this case, at least one of the crystallization prevention layers may be an amorphous selenium layer containing 5% to 40% of the specific element, but both crystallization prevention layers contain amorphous selenium containing 5% to 40% of the specific element. A layer is more preferable.

  The recording photoconductive layer 23 of the radiation image detector in the first mode of the optical reading method and the reading photoconductive layer 27 ′ of the radiation image detector in the second mode of the optical reading method are Na, K, Li, etc. It is a layer which has the amorphous selenium containing the alkali metal as a main component, and the alkali metal content is preferably 0.01 to 5000 ppm. Usually, when the alkali metal content is higher than 0.01 ppm, crystallization is likely to occur at the interface with the upper layer in the first embodiment and at the interface with the lower layer in the second embodiment, so that the number of image defects increases. However, since the radiation image detector of the present invention is provided with the anti-crystallization layer as described above, it is possible to suppress the crystallization at the same time while realizing the deterioration of sensitivity. In addition, quality can be improved.

The recording photoconductive layer 23 ′ of the radiation image detector in the second embodiment of the optical reading method may be any material that generates charges when irradiated with radiation, and has a relatively high quantum efficiency with respect to radiation. Further, PbO, PbI _{2 and the} like which are excellent in terms of high dark resistance are preferable.

  The reading photoconductive layer 27 of the radiation image detector according to the first embodiment of the optical reading method includes a-Se, Se-Te, Se-As-Te, metal-free phthalocyanine, metal phthalocyanine, MgPc (magnesium phtalocyanine), A photoconductive substance having at least one of VoPc (phase II of Vanadyl phthalocyanine), CuPc (Copper phtalocyanine) and the like as a main component is preferable.

As the first electrode 21, a conductive material that can be deposited by resistance heating, such as Au or Al, and can suppress the influence of radiant heat to be low is suitable. As the linear electrode 24, for example, a transparent conductive material (ITO, IZO, etc.) formed on a transparent glass plate and patterned is suitable for smooth edge shape. As the charge transport layer 26, a semiconductor material containing Se such as As ₂ Se ₃ doped with 10 to 3000 ppm of I and a-Se doped with 10 to 200 ppm of Cl is suitable.

Although the above-described optical reading type radiographic image detector can also be produced by a known method, it is preferable that the crystallization preventing layer and the recording photoconductive layer are continuously deposited (deposited) in the same vacuum. Moreover, the effect of preventing crystallization can be further enhanced by stacking at high speed using the same vapor deposition mask.
Examples of the radiation image detector of the present invention are shown below.

(Comparative Example 1)
High purity 5N selenium, Na ₂ Se for Na doping was added and filled in a Pyrex (registered trademark) glass tube, vacuum sealed at 0.1 Pa or less, reacted at 550 ° C., and Na at a molar concentration of 30 ppm. A selenium alloy was produced. This selenium alloy is packed in a stainless steel crucible, and a 5 cm square glass substrate provided with a comb-like amorphous IZO layer under the conditions of a crucible temperature of 280 ° C. and a vacuum degree of 0.0001 Pa, a substrate temperature of 65 ° C. and a deposition rate of 1 μm. An Se film containing Na having a thickness of 10 μm was deposited under the conditions of / min. Next, 0.2 μm of As ₂ Se ₃ (6N manufactured by Furuuchi Chemical Co., Ltd.) was laminated at a crucible temperature of 460 ° C., and a Se film containing Na having a thickness of 200 μm was laminated in the same manner as described above. Subsequently, Sb ₂ S ₃ (6N manufactured by Furuuchi Chemical Co., Ltd.) was laminated at a crucible temperature of 550 ° C. to a thickness of 0.1 μm. Finally, Au was vapor-deposited with a thickness of 60 nm using the upper electrode to produce a device.

(Examples 1-7, Comparative Examples 2-6)
The crystallization prevention layer 22 'shown in Table 1 was inserted on the comb-like amorphous IZO layer of Comparative Example 1, and the crystallization prevention layer 22 shown in Table 1 was inserted below the Sb ₂ S ₃ layer. Produced a device in the same manner as described in Comparative Example 1.

Each crystallization preventing layer was produced by evaporating an Se alloy material containing As having the composition shown in Table 1 at a crucible temperature of 440 ° C. to a thickness of 0.15 μm. At this time, the amount of SeAs raw material charged in the crucible was about 10 times the amount necessary to form a film thickness of 0.15 μm, and the As concentration was controlled by controlling the opening / closing timing and opening / closing time of the shutter provided on the crucible. The distribution was controlled. Specifically, the crystallization preventing layer 22 was performed by opening the substrate shutter in the latter half of the deposition so that the maximum concentration would be at the Sb ₂ S ₃ side interface, and then raising the crucible temperature to 460 ° C. The crystallization preventing layer 22 ′ was formed by opening the substrate shutter at the center of vapor deposition so that the maximum concentration would be at the IZO side interface, and then lowering the crucible temperature to 380 ° C.

  It shows in Table 1 with a result. The charge collection amount, image defect, and offset charge amount in Table 1 were evaluated as follows, and the charge collection amount, the image defect number ratio, and the offset charge amount were all shown as relative values in Comparative Example 1.

(Charge collection amount and image defects)
The charge collection amount was measured using an image reading apparatus described in JP-A-2004-147255. For image defects, a signal is output as a two-dimensional image under the condition that radiation or light is not irradiated using the same reading device. Spots of 50 μm or more (white spots are crystals on the substrate side, black spots are crystals on the upper electrode side) ) And then aged for 2 weeks under dry conditions at 40 ° C., and the spots were similarly counted to calculate the ratio of the number of image defects before and after aging.

The offset charge was measured by applying a reading to the upper electrode without applying radiation or light and applying -2 kV for 2 seconds with the same reader. Here, when the dark current injected from the upper electrode is larger than that of the lower electrode, the polarity of the offset charge amount read out is positive. In the opposite case, the polarity of the offset charge amount is negative. If the offset charge amount is large, it means that the dark current injection amount is large.

In addition, in order to measure As concentration in the film | membrane of the crystallization prevention layer 22 'and the crystallization prevention layer 22 in the device of Comparative Example 2 and Example 1, the Se laminated film was peeled off from the glass substrate, and XPS analysis was performed from both side interfaces. As a result, the average As concentration at the IZO interface 50 nm of the anti-crystallization layer 22 ′ in the device of Comparative Example 2 was 0.05%, and the average As concentration at the Sb ₂ S ₃ interface 50 nm of the anti-crystallization layer 22 was 0. .5%. On the other hand, the average As concentration at the IZO interface 50 nm of the anti-crystallization layer 22 ′ in the device of Example 1 is 4.0%, and the average As concentration at the Sb ₂ S ₃ interface 50 nm of the anti-crystallization layer 22 is 5.5%. Met. The XPS analysis was measured as follows.

(XPS analysis)
Model used: Thermo Electron VG Theta Probe
Irradiation X-ray: Single crystal spectroscopy AlKα
Ion species: Ar ⁺
Etching rate: 0.4 Å / sec (SiO ₂ equivalent value)
Sensitivity correction method: A sample containing Se and As was prepared for sensitivity correction, and the As and Se concentrations were first quantified by ICP-MS analysis. Next, the same sample was subjected to XPS analysis, and a sensitivity correction coefficient was obtained so that As and Se concentrations coincided with the values of ICP-MS analysis. Based on this sensitivity correction coefficient, the distribution of As concentration in a predetermined sample was quantified.

  From the As and Se concentration profiles obtained by XPS analysis, the film thicknesses of the crystallization-preventing layers in Examples 1 to 7 and Comparative Examples 2 to 6 were all found to be 0.15 μm.

  As is apparent from Table 1, Examples 1 to 7 containing 5% to 40% As as the anti-crystallization layer, especially Examples 2 to 5 containing As in both anti-crystallization layers containing 2% to 40%. In No. 6, the reduction in the number of image defects was remarkable. In Examples 5 to 7, the offset charge amount increased from −2 times to −10 times compared to the comparative example, which means that charge injection increased from the positive IZO electrode into the device. ing.

  As described above, the radiographic image detector of the present invention is an As-crystallization layer as an anti-crystallization layer on the interface of the recording photoconductive layer or the reading photoconductive layer mainly composed of amorphous selenium containing an alkali metal. Since an a-Se layer containing 5% to 40% of at least one element selected from the group consisting of Sb and Bi is provided, it is possible to prevent a decrease in sensitivity and an increase in image defects over time. be able to.

Schematic sectional view showing a first embodiment of the radiation image detector (TFT method) of the present invention Schematic sectional view showing a second embodiment of the radiation image detector (TFT method) of the present invention Schematic sectional view showing a third embodiment of the radiation image detector (TFT method) of the present invention Schematic showing the first embodiment of the concentration distribution of As and Se in the anti-crystallization layer Schematic showing the second embodiment of the concentration distribution of As and Se in the anti-crystallization layer Schematic showing the third embodiment of the concentration distribution of As and Se in the anti-crystallization layer Schematic sectional view showing a first aspect of the radiation image detector (optical reading method) of the present invention Schematic sectional view showing a second embodiment of the radiation image detector (optical reading method) of the present invention Schematic sectional view showing a third embodiment of the radiation image detector (optical reading system) of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st electrode 2 Anti-crystallization layer 2 'Anti-crystallization layer 3 Photoconductive layer for recording 4 Charge collection electrode 5 Substrate 10 Radiation image detector 21 First electrode 22 Anti-crystallization layer 22' Anti-crystallization layer 23 For recording Photoconductive layer 23 'photoconductive layer for recording 24 linear electrode 26 charge transport layer 27 photoconductive layer for reading 27' photoconductive layer for reading

Claims (31)

The main component is an amorphous selenium containing an alkali metal that generates a charge by irradiation of the recording electromagnetic wave transmitted through the first electrode and the recording electromagnetic wave carrying the radiation image. In the radiation image detector formed by laminating a recording photoconductive layer, a plurality of charge collecting electrodes, and a substrate in this order,
An amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb, and Bi is provided as an anti-crystallization layer between the first electrode and the recording photoconductive layer. The radiation image detector characterized by the above-mentioned.   The radiation image detector according to claim 1, wherein the crystallization preventing layer has a thickness of 0.05 μm to 0.3 μm. The main component is an amorphous selenium containing an alkali metal that generates a charge by irradiation of the recording electromagnetic wave transmitted through the first electrode and the recording electromagnetic wave carrying the radiation image. In the radiation image detector formed by laminating a recording photoconductive layer, a plurality of charge collecting electrodes, and a substrate in this order,
Between the first electrode and the recording photoconductive layer, an amorphous selenium layer containing at least one element selected from the group consisting of As, Sb and Bi is provided as an anti-crystallization layer, and the crystallization The prevention layer includes at least a region where the element concentration has a maximum value and a region where the element concentration has a concentration of 80% or less of the maximum value concentration.   4. The radiation image detector according to claim 3, wherein the element concentration in a region where the element concentration takes a maximum value is 5% to 40%.   The element concentration in the anti-crystallization layer is within a region of 50 nm interface with the upper layer containing as a main component amorphous selenium located on the opposite side of the anti-crystallization layer from the recording photoconductive layer. The radiation image detector according to claim 3, wherein the radiation image detector takes a maximum value.   4. The radiation image detector according to claim 3, wherein the element concentration in the crystallization preventing layer takes a maximum value in a region of 50 nm interface with the recording photoconductive layer.   An upper layer side region having an interface of 50 nm with an upper layer not containing amorphous selenium as a main component, located on the opposite side of the recording photoconductive layer with respect to the anti-crystallization layer in the anti-crystallization layer, and the crystal The average concentration of the element in the crystallization prevention layer other than the recording photoconductive layer side region at the interface of 50 nm with the recording photoconductive layer in the anticrystallization layer is the maximum value of the element concentration in the upper layer side region. 4. The radiation image detector according to claim 3, wherein the concentration is 80% or less of the smaller one of the maximum values of the element concentrations in the recording photoconductive layer side region. The main component is an amorphous selenium containing an alkali metal that generates a charge by irradiation of the recording electromagnetic wave transmitted through the first electrode and the recording electromagnetic wave carrying the radiation image. In the radiation image detector formed by laminating a recording photoconductive layer, a plurality of charge collecting electrodes, and a substrate in this order,
An amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb, and Bi is provided as an anti-crystallization layer between the charge collection electrode and the recording photoconductive layer. A radiation image detector characterized by comprising:   The radiation image detector according to claim 8, wherein the film thickness of the anti-crystallization layer is 0.05 μm to 0.3 μm. The main component is an amorphous selenium containing an alkali metal that generates a charge by irradiation of the recording electromagnetic wave transmitted through the first electrode and the recording electromagnetic wave carrying the radiation image. In the radiation image detector formed by laminating a recording photoconductive layer, a plurality of charge collecting electrodes, and a substrate in this order,
An amorphous selenium layer containing at least one element selected from the group consisting of As, Sb, and Bi is provided as an anti-crystallization layer between the charge collection electrode and the recording photoconductive layer. The layer includes at least a region in which the element concentration has a maximum value and a region in which the element concentration has a concentration of 80% or less of the maximum value concentration.   The radiation image detector according to claim 10, wherein the element concentration in a region where the element concentration takes a maximum value is 5% to 40%.   The element concentration in the anti-crystallization layer is within a region of 50 nm interface with the lower layer containing as a main component amorphous selenium located on the opposite side of the anti-crystallization layer from the recording photoconductive layer. The radiation image detector according to claim 10, wherein the radiation image detector takes a maximum value.   11. The radiation image detector according to claim 10, wherein the element concentration in the crystallization preventing layer takes a maximum value in a region of 50 nm interface with the recording photoconductive layer.   A lower layer side region having an interface of 50 nm with the lower layer not containing amorphous selenium as a main component, located on the opposite side of the recording photoconductive layer with respect to the anti-crystallization layer in the anti-crystallization layer, and the crystal The average concentration of the element in the anti-crystallization layer other than the recording photoconductive layer side region at the interface with the recording photoconductive layer in the anti-crystallization layer other than 50 nm is the maximum value of the element concentration in the lower layer side region 11. The radiation image detector according to claim 10, wherein the concentration is 80% or less of the smaller one of the maximum element concentration values in the recording photoconductive layer side region.   15. The radiation image detector according to 12 or 14, wherein the lower layer is a semi-insulator layer. The main component is an amorphous selenium containing an alkali metal that generates a charge by irradiation of the recording electromagnetic wave transmitted through the first electrode and the recording electromagnetic wave carrying the radiation image. A photoconductive layer for recording, a power storage unit for accumulating charges generated in the photoconductive layer for recording, a photoconductive layer for reading that generates charges by irradiation of reading light, a number of linear electrodes for reading, In the radiation image detector formed by laminating the substrate in this order,
An amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb, and Bi is provided as an anti-crystallization layer between the first electrode and the recording photoconductive layer. The radiation image detector characterized by the above-mentioned.   The radiation image detector according to claim 16, wherein a thickness of the anti-crystallization layer is 0.05 μm to 0.3 μm. The main component is an amorphous selenium containing an alkali metal that generates a charge by irradiation of the recording electromagnetic wave transmitted through the first electrode and the recording electromagnetic wave carrying the radiation image. A photoconductive layer for recording, a power storage unit for accumulating charges generated in the photoconductive layer for recording, a photoconductive layer for reading that generates charges by irradiation of reading light, a number of linear electrodes for reading, In the radiation image detector formed by laminating the substrate in this order,
Between the first electrode and the recording photoconductive layer, an amorphous selenium layer containing at least one element selected from the group consisting of As, Sb and Bi is provided as an anti-crystallization layer, and the crystallization The prevention layer includes at least a region where the element concentration has a maximum value and a region where the element concentration has a concentration of 80% or less of the maximum value concentration.   19. The radiation image detector according to claim 18, wherein the element concentration in a region where the element concentration takes a maximum value is 5% to 40%.   The element concentration in the anti-crystallization layer is within a region of 50 nm interface with the upper layer containing as a main component amorphous selenium located on the opposite side of the anti-crystallization layer from the recording photoconductive layer. The radiation image detector according to claim 18, wherein the radiation image detector takes a maximum value.   19. The radiation image detector according to claim 18, wherein the element concentration in the crystallization preventing layer takes a maximum value in a region of 50 nm interface with the recording photoconductive layer.   An upper layer side region having an interface of 50 nm with an upper layer not containing amorphous selenium as a main component, which is located on the opposite side of the recording photoconductive layer with respect to the anti-crystallization layer in the anti-crystallization layer, and the crystal The average concentration of the element in the crystallization prevention layer other than the recording photoconductive layer side region at the interface of 50 nm with the recording photoconductive layer in the anticrystallization layer is the maximum value of the element concentration in the upper layer side region. 19. The radiation image detector according to claim 18, wherein the concentration is 80% or less of the smaller one of the maximum values of the element concentrations in the recording photoconductive layer side region. A first electrode that transmits a recording electromagnetic wave carrying a radiographic image; a recording photoconductive layer that generates a charge upon irradiation of the recording electromagnetic wave transmitted through the first electrode; and the recording photoconductive layer. A power storage unit for accumulating charges generated in the layer, a photoconductive layer for reading mainly composed of amorphous selenium containing alkali metal, which generates charges by irradiation of reading light, and a large number of linear electrodes for reading; In the radiation image detector formed by laminating the substrate in this order,
An amorphous selenium layer containing 5% to 40% of at least one element selected from the group consisting of As, Sb, and Bi is provided as an anti-crystallization layer between the linear electrode and the reading photoconductive layer. A radiation image detector characterized by comprising:   24. The radiation image detector according to claim 23, wherein the film thickness of the anti-crystallization layer is 0.05 [mu] m to 0.3 [mu] m. A first electrode that transmits a recording electromagnetic wave carrying a radiographic image; a recording photoconductive layer that generates a charge upon irradiation of the recording electromagnetic wave transmitted through the first electrode; and the recording photoconductive layer. A power storage unit for accumulating charges generated in the layer, a photoconductive layer for reading mainly composed of amorphous selenium containing alkali metal, which generates charges by irradiation of reading light, and a large number of linear electrodes for reading; In the radiation image detector formed by laminating the substrate in this order,
An amorphous selenium layer containing at least one element selected from the group consisting of As, Sb and Bi is provided as an anti-crystallization layer between the linear electrode and the reading photoconductive layer, and the anti-crystallization is provided. The layer includes at least a region in which the element concentration has a maximum value and a region in which the element concentration has a concentration of 80% or less of the maximum value concentration.   26. The radiation image detector according to claim 25, wherein the element concentration in a region where the element concentration takes a maximum value is 5% to 40%.   The element concentration in the anti-crystallization layer is within the region of 50 nm interface with the lower layer containing as a main component amorphous selenium located on the opposite side of the reading photoconductive layer with respect to the anti-crystallization layer. The radiation image detector according to claim 25, wherein the radiation image detector takes a maximum value.   26. The radiation image detector according to claim 25, wherein the element concentration in the crystallization preventing layer takes a maximum value in a region of 50 nm interface with the reading photoconductive layer.   A lower layer side region having an interface of 50 nm with the lower layer not containing amorphous selenium as a main component, which is located on the opposite side of the reading photoconductive layer with respect to the anti-crystallization layer in the anti-crystallization layer, and the crystal The average concentration of the element in the crystallization preventing layer other than the reading photoconductive layer side region at the interface of 50 nm with the reading photoconductive layer in the anticrystallization layer is the maximum value of the element concentration in the lower layer side region 26. The radiation image detector according to claim 25, wherein the concentration is 80% or less of the smaller one of the maximum values of the element concentrations in the reading photoconductive layer side region.   30. The radiation image detector according to 27 or 29, wherein the lower layer is a semi-insulator layer.   31. The radiation image detector according to claim 1, wherein the alkali metal content is 0.01 to 5000 ppm.

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