JP2009267025A - Photosensor, photosensor array, imaging element, and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensor which can reduce leakage current (dark current) generation in a photoelectric conversion layer even in the case where an organic compound is used for the photoelectric conversion layer, to provide a photosensor array, to provide an imaging element, and to provide an imaging apparatus. <P>SOLUTION: There are provided: the photosensor including a substrate, a photoelectric conversion layer which is an organic compound which produces electric charge using the incidence of light on a first surface of the substrate, and a pixel electrode for collecting electric charges produced in the photoelectric conversion layer and having a light collecting member for collecting incident light in the direction of the photoelectric conversion layer on a second surface opposed to the first surface of the substrate; the photosensor array including the photosensor; an imaging element; and the imaging apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical sensor, an optical sensor array, an imaging element, and an imaging apparatus.

  Gretzel et al. Reported a dye-sensitized photoelectric conversion element (Gretzel cell) that has a performance close to that of an amorphous silicon photoelectric conversion element by forming a film of an organic dye having a photoelectric conversion function on a transparent electrode such as titanium oxide. (For example, refer nonpatent literature 1).

  In recent years, a dye-sensitized photoelectric conversion element using a monomolecular film having fullerene has also been reported using a nanotechnology technique (see, for example, Patent Document 1 and Patent Document 2).

  Since these dye-sensitized photoelectric conversion elements are wet photoelectric conversion elements that are electrically bonded to the counter electrode by an electrolytic solution such as a liquid redox electrolyte, when used over a long period of time, There is a concern that the photoelectric conversion function is remarkably deteriorated due to depletion, and the photoelectric conversion element does not function.

  In addition, as a photoelectric conversion element using an organic dye that does not use an electrolytic solution, a bulk heterojunction photoelectric conversion element in which a layer in which an electron donor and an electron acceptor are mixed is formed between a transparent electrode and a counter electrode, or a transparent electrode A stack type (stacked type) photoelectric conversion element has been proposed in which an electron donor layer and an electron acceptor layer are sandwiched between a counter electrode (see, for example, Patent Document 3).

  The operation principle of this photoelectric conversion element is that holes and electrons are generated by the movement of electrons from the electron donor (or electron donor layer) to the electron acceptor (or electron acceptor layer) by photoexcitation, and are generated by an internal electric field. Holes pass between electron donors (or between electron donor layers) and are transported to one electrode, electrons pass between electron acceptors (or between electron acceptor layers) and are transported to the other electrode, photocurrent Is observed.

Next, an X-ray image detector to which the photoelectric conversion element having the above configuration is applied will be described. Amorphous silicon photoelectric conversion elements are used in the medical field as flat panel radiation detectors (FPDs) in addition to applications as photosensitive drums for solar cells and copying machines. Also, photoelectric conversion elements using organic dyes have been proposed for application to FPD (see, for example, Patent Document 4).
JP 2000-261016 A JP 2002-94146 A JP-T-2002-502129 JP 2003-50280 A Journal of the American Chemical Society 115 (1993) 6382

  FPD is a kind of digital X-ray image detector that reads out radiographic images as digital signals and allows diagnosis on monitors such as personal computers without using radiographic films (such as X-ray films). is there. In FPD, a photoelectric conversion element absorbs X-rays directly and performs photoelectric conversion (direct FPD), and a fluorescent substance converts X-rays into fluorescence, and the fluorescence is absorbed by the photoelectric conversion element to perform photoelectric conversion. (Indirect type FPD), and amorphous silicon photoelectric conversion elements and organic dye photoelectric conversion elements are used for the latter indirect FPD.

  The advantage of the indirect FPD using an amorphous silicon photoelectric conversion element is that a high-quality image comparable to a conventional analog system can be obtained. An amorphous silicon photoelectric conversion element is an inorganic semiconductor material such as amorphous silicon. There is a problem that the product price is extremely increased because it is necessary to finely process a thin film transistor on a thin film transistor (TFT), which requires very advanced technology and equipment.

  On the other hand, an indirect FPD using a photoelectric conversion element using an organic dye is advantageous in that it is very easy to process because it uses an organic substance, and the product price is very low.

  However, when a photoelectric conversion element using an organic dye is used, there is a problem that a leak current (dark current) in the photoelectric conversion layer becomes large, and a portion that should be displayed darkly is displayed brightly.

  As a method of reducing the influence of such a leakage current, there is a method of providing an auxiliary capacitance unit and using the capacitance of the auxiliary capacitance unit.

  However, only by increasing the capacitance of the auxiliary capacitance unit without devising the photoelectric conversion layer, there is a problem that the reading time constant increases and information reading is delayed. In addition, there is a problem that the auxiliary capacity portion cannot be increased due to limitations on the configuration of the photoelectric conversion element.

  FIG. 18 is a schematic sectional view showing an example of a pixel portion of a conventional CCD device. The pixel portion of this CCD device has a configuration in which the area of the light receiving surface of the photoelectric conversion element 230 on the silicon substrate 231 having a thickness of several hundred μm is smaller than the area of the pixel portion. A polysilicon film 232 is also formed on the silicon substrate 231, and a light shielding film 233 is formed on part of the surfaces of the polysilicon film 232 and the photoelectric conversion element 231.

  An inner lens 234 is installed above the light shielding film 233, and a color filter 235 is installed above the inner lens 234. Further, a micro lens 236 is installed above the color filter 235.

  The incident light 237 from above the microlens 236 is refracted by the microlens 236, passes through the color filter 235, is further refracted by the inner lens 236, and is then condensed on the photoelectric conversion element 230.

  However, in this CCD device, since the area of the pixel portion is small, the microlens 236 and the inner lens 234 have to be installed above the photoelectric conversion element 230, and these lenses absorb incident light. There was a problem of loss.

  In view of the above circumstances, an object of the present invention is to provide an optical sensor, an optical sensor array, and an optical sensor array that can reduce the amount of leakage current (dark current) generated in the photoelectric conversion layer even when an organic compound is used for the photoelectric conversion layer. An object of the present invention is to provide an imaging device and an imaging device.

  The present invention includes a substrate, a photoelectric conversion layer that is an organic compound that generates a charge upon incidence of light on the first surface of the substrate, a pixel electrode for collecting the charge generated in the photoelectric conversion layer, And a light condensing member for condensing incident light in the direction of the photoelectric conversion layer on the second surface facing the first surface of the substrate.

  Here, in the optical sensor of the present invention, it is preferable that the auxiliary capacitance portion is provided on the first surface of the substrate, and the capacitance in the photoelectric conversion layer is smaller than the capacitance in the auxiliary capacitance portion.

  In the photosensor of the present invention, the pixel electrode may be directly formed on the first surface of the substrate.

  Moreover, in the optical sensor of this invention, it is preferable that the thickness of a photoelectric converting layer is 20 nm or more and 200 nm or less.

  Further, the present invention is an optical sensor array in which any of the above optical sensors is arranged in a lattice pattern.

Moreover, this invention is an image pick-up element containing said optical sensor array.
Furthermore, this invention is an imaging device containing said imaging device.

  According to the present invention, there are provided an optical sensor, an optical sensor array, an imaging device, and an imaging device that can reduce the amount of leakage current (dark current) generated in the photoelectric conversion layer even when an organic compound is used for the photoelectric conversion layer. can do.

  Hereinafter, embodiments of the present invention will be described. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts.

  FIG. 1 shows a schematic cross-sectional view of an example of the optical sensor of the present invention. Here, in the optical sensor, the auxiliary capacitance electrode 9 and the gate electrode 11 are formed on one surface of the substrate 1, and the insulating film 15 is formed so as to cover the auxiliary capacitance electrode 9. The pixel electrode 7 is formed so as to cover a part of the surface and a part of the surface of the insulating film 15. An insulating film 16 is formed on a part of the surface of the pixel electrode 7.

  A gate insulating film 10 is formed so as to cover the gate electrode 11. On the gate insulating film 10, the source electrode 19 electrically connected to the signal line 212 and the drain electrode 12 electrically connected to the pixel electrode 7 are formed to face each other with a predetermined interval. The pixel electrode 7 is formed so as to be electrically connected to the drain electrode 12. Further, an active layer 13 is formed so as to cover the source electrode 19 and the drain electrode 12 and to be in contact with the gate insulating film 10. The gate insulating film 10, the gate electrode 11, the drain electrode 12, the source electrode 19, and the active layer 13 constitute a TFT (Thin Film Transistor) as an active element.

  Further, a passivation film 2 is formed so as to cover the TFT and a part of the pixel electrode 7, and an organic compound that generates an electric charge upon incidence of light on the passivation film 2, the pixel electrode 7, and the insulating film 16. A certain photoelectric conversion layer 6, the common electrode 5, and the protective film 3 are laminated in this order.

  A spherical convex condensing member 4 is provided on the surface of the substrate 1 opposite to the pixel electrode 7 formation side. In the present embodiment, the condensing member 4 has a function of condensing incident light incident on the condensing member 4 onto the photoelectric conversion layer 6 through the pixel electrode 7.

  In the optical sensor having the above-described configuration, the light incident on the light collecting member 4 is collected by the light collecting member 4 and incident on the photoelectric conversion layer 6, and an electric charge is generated in the photoelectric conversion layer 6 by the incident light. . Then, charges are extracted from the pixel electrode 7 by a bias voltage applied between the common electrode 5 and the pixel electrode 7. Then, charges are transferred from the pixel electrode 7 to the drain electrode 12 of the TFT.

  Then, by applying a voltage to the gate electrode 11, the charge held in the drain electrode 12 of the TFT is transferred to the source electrode 19 and taken out from the signal line 212 to the outside. That is, the discharge of the TFT charge is controlled depending on whether or not a voltage is applied to the gate electrode 11.

  In the optical sensor of the present invention configured as described above, the light collecting member 4 is formed on the surface of the substrate 1 opposite to the side on which the pixel electrode 7 is formed, and the light incident on the light collecting member 4 is formed. Can be condensed and incident on the photoelectric conversion layer 6, so that the amount of light incident on the photoelectric conversion layer 6 can be increased.

  Therefore, in the optical sensor of the present invention, since the area of the light receiving surface of the photoelectric conversion layer 6 can be reduced, the absolute amount of leakage current (dark current) generated in the photoelectric conversion layer 6 can be reduced. Compared to the conventional case, even when an organic compound is used for the photoelectric conversion layer 6, the amount of leakage current (dark current) generated in the photoelectric conversion layer 6 can be reduced.

  That is, by reducing the area of the light receiving surface of the photoelectric conversion layer 6, the absolute amount of leakage current (dark current) generated in the photoelectric conversion layer 6 can be reduced. In this case, the photoelectric conversion layer 6 The loss of the amount of incident light increases as the area of the light receiving surface decreases. Therefore, the loss of the amount of incident light can be suppressed by installing the condensing member 4 that can condense on the light receiving surface of the photoelectric conversion layer 6 as described above.

  For example, in the optical sensor of the present invention, the area of the surface of the photoelectric conversion layer 6 can be reduced to about 20% of the area of the pixel area of one pixel, thereby causing leakage current generated in the photoelectric conversion layer 6. The absolute amount of (dark current) can be reduced.

  With such a configuration, in the optical sensor of the present invention, the amount of leakage current (dark current) generated in the photoelectric conversion layer 6 can be reduced while maintaining the conventional optical characteristics.

  If the diameter d of the light collecting member 4 is about 100 μm and the height h of the light collecting member 4 is about 40 μm, for example, the width of the pixel electrode 7 ( For example, light incident in a wider range than 30 μm) can be collected on the pixel electrode 7.

  Here, in the optical sensor of the present invention, it is preferable that the capacitance in the photoelectric conversion layer 6 is smaller than the capacitance in the auxiliary capacitance portion of the TFT. In this case, the amount of leakage current (dark current) generated in the photoelectric conversion layer 6 tends to be further reduced.

  In addition, the electrostatic capacitance C1 in the photoelectric conversion layer 6 can be calculated by the following equation (1), and the electrostatic capacitance C2 in the auxiliary capacitance portion can be calculated by the following equation (2).

C1 = (relative permittivity ε1 of photoelectric conversion layer 6) × (vacuum permittivity ε ₀ ) × (area S1 of surface of pixel electrode 7 in contact with photoelectric conversion layer 6) / (photoelectric conversion on pixel electrode 7) Layer 6 thickness D1) (1)
C2 = (the relative dielectric constant ε2 of the gate insulating film 15 covering the surface of the auxiliary capacitance electrode 9) × (vacuum dielectric constant ε ₀ ) × (area S2 of the surface of the auxiliary capacitance electrode 9) / (the surface of the auxiliary capacitance electrode 9) Thickness D2 of gate insulating film 15 to cover (2)
Moreover, it is preferable that the thickness D1 of the photoelectric converting layer 6 is 20 nm or more and 200 nm or less. When the thickness D1 of the photoelectric conversion layer 6 is less than 20 nm, the leakage current (dark current) may increase rapidly due to aggregates in the photoelectric conversion layer 6. When the thickness D1 of the photoelectric conversion layer 6 exceeds 200 nm, a region in which the current flows in the photoelectric conversion layer 6 becomes large, and the leakage current (dark current) may increase rapidly.

  FIG. 13A shows a schematic top view of an example of the experimental apparatus, and FIG. 13B shows a schematic cross-sectional structure of the experimental apparatus shown in FIG. As shown in FIGS. 13 (a) and 13 (b), this experimental apparatus includes a lower electrode 182 made of ITO, P3HT (Poly (3-hexylthiophene)) and PCBM (phenyl C61-butyric) on a glass substrate 183. 10 elements in which a bulk heterojunction photoelectric conversion layer 6 made of a mixture with acid methyl ester) and an upper electrode 181 made of Al are sequentially laminated are connected in parallel. In FIGS. 13A and 13B, only two elements are shown for convenience of explanation.

  Here, the upper electrode 181 is formed in a square shape having a side of 180 μm, and the photoelectric conversion layer 6 and the lower electrode 182 are each formed in a square shape having a side of 400 μm.

  This experimental apparatus was produced as follows. First, a resist pattern having the shape of the lower electrode 182 is formed on the surface of ITO of the glass substrate with ITO using a photolithography technique, and the ITO not covered with the resist pattern is etched to form ITO on the glass substrate 183. A lower electrode 182 made of is formed.

Next, the entire glass substrate 183 on which the lower electrode 182 is formed is subjected to a liquid repellent treatment by a low pressure plasma method using CF ₄ gas. Then, a portion other than the lower electrode 182 on the surface of the glass substrate 183 is shielded with a metal mask, and then UV ozone irradiation is performed to lyophilicize the lower electrode 182.

  Thereafter, a mixed solution of P3HT and PCBM is applied to the entire surface of the glass substrate 183 by a spin coating method. Thereby, the photoelectric conversion layer 6 is formed only in the part of the lower electrode 182 that has been subjected to the lyophilic treatment. Finally, using a metal mask, Al was deposited on the surface of the photoelectric conversion layer 6 in the shape of the upper electrode 181 by a vacuum deposition method, whereby the experimental apparatus having the configuration shown in FIGS. 13A and 13B was obtained. Produced.

  A mixed solution of P3HT and PCBM was produced as shown in FIG. First, a solution 192 obtained by applying ultrasonic waves for 5 minutes to chloroform added with 1% by weight of P3HT manufactured by Merck Co., Ltd. was placed in the first container 190, and ultrasonic waves were applied to chloroform added with 1% by weight of PCBM manufactured by Frontier Carbon. The solution 193 to which was applied for 5 minutes was accommodated in the second container 191. In the third container 194, the solution 192 accommodated in the first container 190 and the solution 193 accommodated in the second container 191 are mixed at a mixing ratio (weight ratio) of 1: 1. Then, an ultrasonic wave was applied for 5 minutes to prepare a mixed solution 195 of P3HT and PCBM.

  Then, as described above, experimental devices having different thicknesses (the shortest distance between the upper electrode 181 and the lower electrode 182) of the photoelectric conversion layer 6 (10 nm to 1000 nm) are manufactured, and the upper portions of the respective experimental devices are formed. A voltage of 0 volts was applied to the electrode 181 and a voltage of -2 volts was applied to the lower electrode 182 to measure the current density. The results are shown in Table 1. At the time of measuring the current density, the elements constituting the experimental device were installed in a dark box.

As shown in Table 1, when the thickness of the photoelectric conversion layer 6 is 20 nm or more and 200 nm or less, the measured current density is 0.1 μA / cm ² and the thickness of the photoelectric conversion layer 6 is 18 nm or less. It was confirmed that the current density was reduced as compared with the case of 205 nm or more.

  This is because when the thickness of the photoelectric conversion layer 6 is 18 nm or less, it is considered that undissolved P3HT and / or PCBM are aggregated to form a leak path. For confirmation, a liquid mixture 195 of P3HT and PCBM produced as shown in FIG. 14 was applied on the surface of a glass substrate and observed with a microscope. As a result, an aggregate having a particle size of about 10 to 20 nm was observed. Many were observed.

  Moreover, when the thickness of the photoelectric converting layer 6 exceeds 200 nm, it is thought that the area | region where an electric current flows in the photoelectric converting layer 6 is large, ie, an electric field spreads. Moreover, the electric field concentration resulting from the nonuniformity of the photoelectric converting layer 6 by forming the photoelectric converting layer 6 thick is also considered.

  In the above, the material of the substrate 1 can be used without particular limitation as long as it is an insulating material capable of transmitting incident light. For example, a glass substrate, polyethylene terephthalate (PET), polyethylene naphthalate ( PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), etc. A film substrate can be used.

  Moreover, in the above, as a material of the passivation film 2 and the protective film 3, respectively, a polyimide etc. can be used, for example.

  In the above, the material of the light collecting member 4 can be used without particular limitation as long as it is a material that can transmit incident light. For example, acrylic, urethane, epoxy, polyimide, etc. Resin can be used. As the resin, any of a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, and the like can be used.

  In the above, the common electrode 5, the auxiliary capacitance electrode 9, the gate electrode 11, the drain electrode 12, the signal line 212, and the source electrode 19 can be used without any particular limitation as long as they are conductive materials. Metals such as Cr, Au, and Ag, transparent conductive films such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), SnO, and ZnO, or conventionally known conductive organic materials can be used. The pixel electrode 7 is preferably made of a conductive material that transmits incident light, such as the above-described transparent conductive film, in order to transmit incident light.

  In the above, as the photoelectric conversion layer 6, a conventionally known organic compound that generates a charge upon incidence of light can be used. For example, an organic compound that functions as an electron donor and an organic that functions as an electron acceptor. It is possible to use a stack type photoelectric conversion layer or the like in which a layer composed of a compound heterogeneous layer or a layer composed of an organic compound functioning as an electron donor and a layer composed of an organic compound functioning as an electron acceptor are stacked. it can. Here, P3HT or the like can be used as the organic compound that functions as an electron donor, and PCBM or the like can be used as an organic compound that functions as an electron acceptor.

  In the above, between the photoelectric conversion layer 6 and the pixel electrode 7, for example, a buffer layer made of a mixture of PEDOT (Poly (3,4-ethylenedioxythiophene)) and PSS (Poly (4-styrenesulfonate)), etc. May be formed.

  In the above, the gate insulating film 10, the insulating film 15, and the insulating film 16 can be used without particular limitation as long as they are insulating materials. For example, acrylic, urethane, epoxy, polyimide, and the like can be used. A plastic resin, a thermosetting resin, an ultraviolet curable resin, or the like can be used.

  In the above, the active layer 13 is not limited to an insulating organic material, but an insulating organic material is used in that the active layer 13 can be formed by a method such as printing or coating. preferable. Examples of the insulating organic material used for the active layer 13 include polythiophenes such as poly (3-hexylthiophene), aromatic oligomers such as oligothiophene having side chains based on a thiophene hexamer, and pentacene. Pentacenes having a substituent and enhanced solubility, a copolymer of fluorene and bithiophene (F8T2), polythienylene vinylene, phthalocyanine, or the like can be used.

  Below, an example of the manufacturing method of the optical sensor of this invention which has said structure is demonstrated. First, as shown in the schematic cross-sectional view of FIG. 2, the gate electrode 11 and the auxiliary capacitance electrode 9 patterned in a strip shape are formed on the substrate 1.

  Here, the gate electrode 11 and the auxiliary capacitance electrode 9 are resists so as to cover the region other than the formation region of the gate electrode 11 and the auxiliary capacitance electrode 9 on the surface of the substrate 1 by using, for example, a photolithography technique. After forming a pattern and laminating a metal or the like by a vacuum vapor deposition method or the like, it can be formed by removing the resist pattern together with the metal or the like laminated by lift-off.

  The formation method of the gate electrode 11 and the auxiliary capacitance electrode 9 is not limited to the above method, and any method can be used as long as the formation method can pattern the gate electrode 11 and the auxiliary capacitance electrode 9 into a desired shape. For example, in addition to the above, a mask vapor deposition method or various printing methods can also be used.

  Next, as shown in the schematic cross-sectional view of FIG. 3, the gate insulating film 10 is formed so as to cover the gate electrode 11, and the source electrode electrically connected to the signal line 212 is formed on the gate insulating film 10. 19, the drain electrode 12 facing the source electrode 19 with a predetermined gap, and the pixel electrode 7 electrically connected to the drain electrode 12 so as to face each other with a predetermined gap, and then forming the source electrode An active layer 13 that covers the gate electrode 19 and the drain electrode 12 and is in contact with the gate insulating film 10 is formed. The pixel electrode 7 is formed so as to cover the insulating film 15 after forming the insulating film 15 on the auxiliary capacitance electrode 9.

  Here, as a method for forming the gate insulating film 10, the insulating film 15, and the insulating film 16, any method can be used as long as the gate insulating film 10 can be patterned into a desired shape. A method of applying a resin constituting the film 10, the insulating film 15, and the insulating film 16 can be used.

  Further, the method for forming the pixel electrode 7, the signal line 212, the source electrode 19 and the drain electrode 12 is not particularly limited as long as the pixel electrode 7, the source electrode 19 and the drain electrode 12 can be patterned into desired shapes. For example, the gate electrode 11 and the auxiliary capacitance electrode 9 can be formed by the same method.

  Moreover, the formation method of the active layer 13 is not specifically limited, For example, it can form by the method of printing or apply | coating the insulating organic material which comprises the active layer 13. FIG.

  As described above, a TFT including the gate insulating film 10, the gate electrode 11, the drain electrode 12, the source electrode 19, and the active layer 13 is formed.

  Next, the passivation film 2 and the insulating film 16 are formed so as to cover a part of the TFT and the pixel electrode 7. Thereafter, as shown in the schematic cross-sectional view of FIG. 4, the photoelectric conversion layer 6 and the common electrode 5 are laminated in this order on the passivation film 2, the pixel electrode 7, and the insulating film 16.

  Here, the method for forming the passivation film 2 is not particularly limited, and for example, a method of applying a resin such as polyimide by a spin coating method or the like can be used.

  Also, the method for forming the photoelectric conversion layer 6 is not particularly limited. For example, a method of drying after applying a liquid precursor of an organic compound that generates an electric charge by incidence of light by a spin coating method or the like can be used.

  Also, the method for forming the common electrode 5 is not particularly limited, and for example, a method of laminating metals or the like by a vacuum deposition method or the like can be used.

  Next, as shown in the schematic cross-sectional view of FIG. 5, the protective film 3 is formed on the surface of the common electrode 5, and the light collecting member is formed on the surface of the substrate 1 opposite to the side on which the pixel electrode 7 is formed. 4 is formed.

  Here, the method for forming the protective film 3 is not particularly limited, and for example, a method of applying a resin such as polyimide by a spin coating method or the like can be used.

  Moreover, the condensing member 4 can be installed, for example, by attaching the separately formed condensing member 4 to the surface of the substrate 1 using an adhesive or the like.

As described above, the optical sensor of the present invention having the configuration shown in FIG. 1 can be manufactured.
In addition, the condensing member 4 used for this invention can be produced as follows, for example. Here, an example of a method for producing the light collecting member is illustrated in FIGS.

  First, as shown in the schematic configuration diagram of FIG. 6, a film base 140 having a thickness of 75 μm is formed between the primer application roll 143 and the impression cylinder roll 144 with biaxially stretched PET whose one surface is easily bonded. Let it pass. Here, the primer 141 accommodated in the ink pan 142 is transferred to the coating roll 143, and the primer transferred to the coating roll 143 passes when the film substrate 140 passes between the coating roll 143 and the impression cylinder roll 144. Transferred to the film substrate 140.

  Next, after the film substrate 140 after the transfer of the primer is dried in the drying zone 145, the UV curable resin 1411 discharged from the nozzle coating device 1410 is recessed on the surface of the film substrate 140 on the primer application side. The nip roll 146 is brought into close contact with the surface of the roll intaglio 149 filled in the nip.

  Subsequently, the ultraviolet curable resin 1411 is cured by irradiating the ultraviolet curable resin 1411 with ultraviolet rays from the ultraviolet irradiation device 147, and is integrated with the film substrate 140.

  Thereafter, when the film substrate 140 passes through the nip roll 148, the film substrate 140 is peeled from the roll intaglio 149 to obtain a shaped film sheet 1412.

  Here, in the above, as the ultraviolet curable resin 1411, for example, a resin mainly composed of a urethane acrylic polyfunctional prepolymer can be used.

  In FIG. 7, the typical perspective view of an example of the shaping film sheet 1412 produced as mentioned above is shown. Here, in the shaping film sheet 1412 having the configuration shown in FIG. 7A, the ultraviolet curable resin 1411 is formed in a triangular prism shape. Moreover, in the shaping film sheet 1412 shown in FIG.7 (b), the ultraviolet curable resin 1411 is formed in the waveform. Moreover, in the shaping film sheet 1412 shown in FIG.7 (c), the ultraviolet curable resin 1411 is formed in the pyramid shape.

  Next, as shown in the schematic cross-sectional view of FIG. 8A, for example, the shaped film sheet 1412 shown in FIG. 7A is set in a mold of an injection molding machine. Here, the shaping film sheet 1412 is sandwiched between a flat-shaped female mold 166 and a mouth-shaped female mold 165, and a male mold 164 having an opening 163 on the mouth-shaped female mold 165 side. Is installed.

  Subsequently, as shown in the schematic cross-sectional view of FIG. 8B, the male mold 164 is placed on the surface of the mouth-shaped female mold 165 so as to be in contact therewith. And resin 167 is inject | poured from the opening part 163 of the male type | mold 164, as shown to the typical sectional drawing of FIG.8 (c). Thereafter, the resin 167 is cured by cooling the resin 167 or the like.

  Next, as shown in the schematic cross-sectional view of FIG. 8D, demolding is performed by pulling apart the mouth-shaped female mold 165, the flat female mold 166, and the male mold 164 from each other. Then, the molded film sheet 1412 after the resin 167 is cured is taken out from the mold of the injection molding machine, and the resin 167 is removed from the molded film sheet 1412 as shown in the schematic cross-sectional view of FIG. Let go. Thereafter, the light collecting member 4 is formed from the resin 167 detached from the shaping film sheet 1412.

  Further, another example of the method for producing the light collecting member is illustrated in the schematic cross-sectional views of FIGS.

  First, as shown in FIG. 9A, for example, a shaped film sheet 1412 having a configuration shown in FIG. 7B is set in a mold of a hot press machine. Here, the shaping film sheet 1412 is installed together with the resin 167 between the upper heating plate 170 and the lower heating plate 174.

  Next, as shown in FIG. 9B, the upper heating plate 170 is pressed to the lower heating plate 174 side to heat and melt the resin 167 and the shape of the ultraviolet curable resin 1411 of the shaped film sheet 1412. Resin 167 is molded into

  Subsequently, after the molded resin 167 is cured by cooling or the like, the resin 167 is detached from the shaped film sheet 1412 as shown in FIG. 9C. Then, the shaping film sheet 1412 after the resin 167 is cured is taken out from the heating press, and then the light collecting member 4 is formed from the resin 167 detached from the shaping film sheet 1412.

  Furthermore, still another example of the method for producing the light collecting member is illustrated in the schematic cross-sectional views of FIGS. 10 and 11 and the schematic configuration diagram of FIG.

  First, as shown in FIG. 10, a lens material layer 101 is laminated on the surface of the substrate 1 by, for example, a method of applying a resin by spin coating, and a resist 102 is laminated on the surface of the lens material layer 101. Form the body.

  Here, a novolac positive resist or the like can be used as the resist 102. The resist 102 is formed on the entire surface of the lens material layer 101 and then patterned into a predetermined shape using a photolithography technique. When heated, it is softened to form a hemisphere.

Next, as shown in FIG. 11, the hemispherical resist 102 and the lens material layer 101 are etched. This etching can be anisotropic reactive ion etching (RIE) using, for example, a mixed gas of CF ₄ and O ₂ as the etching gas 103. This RIE can be performed under the condition that the etching selection ratio between the resist 102 and the lens material layer 101 is approximately 1. Thereby, the hemispherical shape of the resist 102 is transferred to the lens material layer 101, and the light collecting member 4 made of the hemispherical lens material layer 101 is formed.

  FIG. 12 shows a schematic configuration of a magnetron RIE apparatus as an example of an apparatus that can be used for the above RIE. As shown in FIG. 12, the magnetron RIE apparatus 107 has an upper electrode 109 and a lower electrode 108 that are arranged in parallel to each other in a chamber 106. The upper electrode 109 is provided with a magnet 104 to form a magnetic field. Further, the laminated body 110 is installed on the lower electrode 108, and a high frequency voltage is applied to the lower electrode 108 from the high frequency power source 105. Here, the energy of ions incident on the stacked body 110 is controlled by changing the power of the high-frequency power source 105.

  In addition, the formation method of the condensing member 4 is not limited to said method, For example, it can produce suitably using a photolithographic technique, microcontact printing, a dicing (cutting) process, an electrocasting method, etc. .

  Moreover, the optical sensor of the present invention having the above-described configuration forms an optical sensor array by being arranged in a lattice pattern, and the optical sensor configured as such can be suitably used for an imaging device, for example. In addition, the imaging device including the optical sensor of the present invention can be suitably used for an imaging device such as an FPD.

  FIG. 15 is a schematic perspective perspective view of a radiographic image detector which is an example of an imaging device including an optical sensor array formed by arranging optical sensors of the present invention in a grid pattern.

  Here, the radiographic image detector includes an image output from the imaging panel 201 using the imaging panel 201, a control circuit 205 that controls the operation of the radiographic image detector, a rewritable read-only memory (for example, a flash memory), and the like. A memory unit 206 capable of storing signals and reading out the stored image signals, an operation unit 203 for switching the operation of the radiation image detector, completion of radiographic image capturing preparation and a predetermined amount of image signals in the memory unit 206 Display unit 202 indicating that data has been written, power supply unit 209 that supplies power required to drive imaging panel 201 to obtain an image signal, radiation image detector, and imaging apparatus including the radiation image detector A communication connector 204 for performing communication with the image processing unit and a housing 200 for housing these are provided.

  In addition, the imaging panel 201 includes a scanning drive circuit 208 that reads out accumulated charges according to the intensity of irradiated radiation, and a signal selection circuit 207 that outputs the accumulated charges as an image signal.

  FIG. 16 shows a circuit configuration of the radiation image detector shown in FIG. For example, the optical sensor of the present invention shown in FIG. 1 is installed on the imaging panel 201, and one pixel electrode 7 of the optical sensor of the present invention corresponds to one pixel of the radiation image. In this radiographic image detector, the pixel electrode 7 is used for reading out the accumulated electric charge according to the intensity of the radiation applied to the photosensor of the present invention.

  Here, scanning lines 213-1, 212-2, 213-3,... 213-m and signal lines 212-1, 212-2, 212-3,. They are arranged so as to be orthogonal.

  In addition, the imaging panel 201 includes a TFT 211- (1, 1) composed of the gate insulating film 10, the gate electrode 11, the drain electrode 12, the source electrode 19 and the active layer 13 of the photosensor of the present invention shown in FIG. ) Is installed.

  Note that, as described above, the pixel electrode 7 and the TFT 211- (1, 1) are electrically connected. Further, the gate electrode 11 of the TFT of the optical sensor of the present invention installed on the imaging panel 201 is connected to the scanning line 213-1, and the source electrode 19 is connected to the signal line 212-1.

  Further, the drain electrode 12 of the TFT of the photosensor of the present invention is connected to the pixel electrode 7. The common electrode 5 of the photosensor of the present invention is connected to a bias power source (not shown), and a negative bias voltage is applied to the common electrode 5. Here, the description has been made by paying attention to one pixel, but pixel electrodes, TFTs, scanning lines, and signal lines are similarly connected to other pixels.

  In addition, the imaging panel 201 includes initialization transistors 215-1 and 215-2, for example, drain electrodes connected to the signal lines 212-1, 212-2, 212-3,. 215-3,... 215-n are provided. The source electrodes of the initialization transistors 215-1, 215-2, 215-3,... 215-n are grounded. Further, the gate electrodes of the initialization transistors 215-1, 215-2, 215-3,... 215-n are connected to the reset line 214.

  In addition, the scanning lines 213-1, 213-2, 213-3... 213 -m and the reset line 214 of the imaging panel 201 are connected to the scanning drive circuit 208.

  In the radiographic image detector having such a circuit configuration, one of the scanning lines 213-1, 213-2, 213-3, ... 213-m from the scanning drive circuit 208 is scanned 213-p (p When the readout signal RS is supplied to any one of 1 to m), the TFTs 211- (p, 1) to 211- (p, n) connected to the scanning line 223-p are turned on. Thus, the accumulated charges are read out to the signal lines 212-1, 212-2, 212-3 to 212-n, respectively. The signal lines 212-1, 212-2, 212-3 to 212-n are connected to signal converters 216-1, 216-2, 216-3, ... 216-n of the signal selection circuit 207. , Signal converters 216-1, 216-2, 216-3,... 216-n are proportional to the amount of charge read out on signal lines 212-1, 212-2, 212-3 to 212-n. To generate voltage signals SV-1, SV-2, SV-3,... SV-n. The voltage signals SV-1, SV-2, SV-3,... SV-n output from the signal converters 216-1, 216-2, 216-3,. Supplied.

  In the register 217, the supplied voltage signal is sequentially selected and converted into a digital image signal DP for one scanning line (for example, 12 bits to 14 bits) by the A / D converter 218 and supplied to the control circuit 205. Is done. Further, the control circuit 205 supplies a read signal RC to the scanning drive circuit 208, and sequentially passes through the scanning drive circuit 208 for each of the scanning lines 213-1, 213-2, 213-3, ... 213-m. The readout signal RS is supplied to scan the image, and the digital image signal for each scanning line is taken in the same manner as described above. And the image signal of a radiographic image is produced | generated. Note that the control circuit 205 controls the signal selection circuit 207 by supplying the control signal SC to the signal selection circuit 207.

  Note that the reset signal RT is supplied from the scanning drive circuit 208 to the reset line 214 to turn on the transistors 215-1 to 215-n, and the readout signal RS is supplied to the scanning lines 213-1 to 213-m. When the TFTs 211-(1, 1) to 211 (m, n) are turned on, the stored charges are passed through initialization transistors 215-1, 215-2, 215-3,. And the imaging panel 201 can be initialized.

In addition, a display unit 202, an operation unit 203, a connector 204, and a memory unit 206 are connected to the control circuit 205, and these are driven by supplying power from the power supply unit 209. Here, the control circuit 205 controls the operation of the radiation image detector based on the operation signal PS from the operation unit 203. The operation unit 203 includes a plurality of switches. When the operation signal PS corresponding to the switch operation from the operation unit 203 is supplied to the control circuit 205, the control circuit 205 initializes the imaging panel 201. Generation of an image signal of the radiation image is performed. The generation of the image signal of the radiation image may be performed when the radiation irradiation end signal _DFE is supplied from the radiation generator via the connector 204. Further, processing for storing the image signal DT generated by the control circuit 205 in the memory unit 206 can be performed. Further, by supplying the display signal DS from the control circuit 205 to the display unit 202, the display unit 202 displays the completion of radiographic image capturing preparation and the fact that a predetermined amount of image signal has been written in the memory unit 206.

FIG. 17 shows a schematic configuration of an example of an imaging apparatus including the radiation image detector configured as shown in FIG. Here, in this imaging apparatus, the radiation emitted from the radiation generator 222 is applied to the radiation image detector 221 having the configuration shown in FIG. 15 through the subject (for example, a patient in a medical facility) 220. Then, the radiation image detector 221 generates an image signal _DFE based on the intensity of the irradiated radiation. The generated image signal _DFE is read out by the image processing unit 223 connected to the radiation image detector 221. Alternatively, after being stored in a portable recording medium such as a semiconductor memory card attached to the radiation image detector 221, the recording medium is detached from the radiation image detector 221 and attached to the image processing unit 223. It is supplied to the processing unit 223.

In the image processing unit 223, the image signal _DFE generated by the radiation image detector 221 is subjected to shading correction, gain correction, gradation correction, edge enhancement processing, dynamic range compression processing, and the like, and is suitable for diagnosis and the like. It is possible to perform processing so as to obtain an image signal. The image processing unit 223 is connected to an image display unit 225 configured using a cathode ray tube, a liquid crystal display element, a projector, or the like. An image based on the image signal after the completion of processing can be displayed.

  In addition, the image processing unit 223 can perform image signal compression and expansion in order to enlarge and reduce the image and to facilitate storage and transfer of the image signal. For this reason, by confirming that the image displayed on the image display unit 225 is enlarged or reduced, it is possible to easily check the imaging region and to perform the processing state. In addition, it is possible to designate a displayed image or a region of the displayed image and automatically perform appropriate image processing on the designated image or the designated region.

  The image processing unit 223 is connected to an information input unit 224 configured using a keyboard, a mouse, a pointer, and the like. Patient information and the like are input by the information input unit 224, and additional information is converted into an image signal. Can be added. The information input unit 224 also designates image processing, stores and reads out image signals, and instructs when performing transmission / reception of image signals via a network.

  Further, an image output unit 228, an image storage unit 226, and a computer-aided image automatic diagnosis unit (CAD) 227 are further connected to the image processing unit 223, respectively.

  The image output unit 228 displays and outputs a radiation image on a recording sheet, a film, or the like. For example, assuming that a silver salt photographic film is used, exposure is performed based on the image signal, and the exposed silver salt photographic film is developed to draw and output a radiographic image as a silver image.

  In addition, when printing and outputting a radiographic image on recording paper, an ink jet printer that applies pressure to the ink based on the image signal and sprays the ink on the recording paper from the tip of a thin nozzle, and prints based on the image signal A thermal printer that melts or sublimates ink and transfers an image onto recording paper. Scans the photoconductor with a laser beam based on the image signal, transfers the toner adhering to the photoconductor to the paper, and then uses heat and pressure. The image output unit 228 can be configured using a laser printer or the like that forms an image on recording paper by fixing.

  Further, the image storage unit 226 can store the radiographic image signal so that it can be read out as needed. The image storage unit 226 can store an image signal by using, for example, magnetic, hologram element, perforation, dye distribution change, and the like.

  In addition, the CAD 227 can perform diagnosis support so that a lesion is not overlooked by, for example, performing computer processing or computer analysis of a captured radiographic image and providing doctors with information necessary for diagnosis. The CAD 227 can automatically perform diagnosis based on, for example, computer processing or computer analysis results.

  In addition, the image signal of the radiographic image is not limited to the image output unit 228, the image storage unit 226, and the CAD 227 described above, but is transmitted to other hospital facilities via a network 2214 such as a so-called LAN, the Internet, and a PACS (medical image network). Can also be sent to other departments or remote locations.

  Also, through this network 2214, image signals obtained from CT (Computed Tomography) 229 and MRI (Magnetic Resonance Imaging) 2210, image signals obtained from CR (Computed Radiography) and other FPDs 2211, and other inspections. Information etc. can also be sent, and the image display unit 225 displays image signals, inspection information, etc. sent via the network 2214 for comparison with the radiographic image obtained by the radiographic image detector 221. Or output from the image output unit 228.

  Further, the transmitted image signal, inspection information, and the like can be stored in the image storage unit 226. Further, the image signal of the radiographic image obtained by the radiographic image detector 221 is stored in the external image storage device 2212, or obtained on the display screen of the external image display device 2213 by the radiographic image detector 221. A radiographic image can be displayed or performed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the present invention, there are provided an optical sensor, an optical sensor array, an imaging device, and an imaging device that can reduce the amount of leakage current (dark current) generated in the photoelectric conversion layer even when an organic compound is used for the photoelectric conversion layer. can do.

It is typical sectional drawing of an example of the optical sensor of this invention. It is typical sectional drawing which illustrates a part of process of an example of the manufacturing method of the optical sensor of this invention which has the structure shown in FIG. It is typical sectional drawing which illustrates a part of process of an example of the manufacturing method of the optical sensor of this invention which has the structure shown in FIG. It is typical sectional drawing which illustrates a part of process of an example of the manufacturing method of the optical sensor of this invention which has the structure shown in FIG. It is typical sectional drawing which illustrates a part of process of an example of the manufacturing method of the optical sensor of this invention which has the structure shown in FIG. It is a typical block diagram illustrating an example of the manufacturing method of the condensing member used for this invention. (A)-(c) is a typical perspective view of an example of the shaping film sheet used for this invention. (A)-(e) is typical sectional drawing illustrating a part of process of an example of the preparation method of the condensing member used for this invention. (A)-(c) is typical sectional drawing illustrating a part of process of another example of the preparation methods of the condensing member used for this invention. It is typical sectional drawing illustrating a part of process of another example of the manufacturing method of the condensing member used for this invention. It is typical sectional drawing illustrating a part of process of another example of the manufacturing method of the condensing member used for this invention. It is a typical block diagram of an example of the apparatus used for the preparation method of the condensing member used for this invention. (A) is a typical upper surface block diagram of an example of an experimental apparatus, (b) is a typical cross-sectional block diagram of the experimental apparatus shown to (a). It is a schematic diagram illustrating the preparation method of the liquid mixture for producing the photoelectric converting layer used by experiment. It is a typical perspective perspective view of the radiographic image detector which is an example of the image pick-up element containing the optical sensor array formed by arranging the optical sensor of this invention in a grid | lattice form. It is a circuit block diagram of the radiographic image detector shown in FIG. It is a typical block diagram of an example of an imaging device containing the radiographic image detector of a structure shown in FIG. It is typical sectional drawing of an example of the pixel part of the conventional CCD device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Substrate, 2 Passivation film, 3 Protective film, 4 Condensing member, 5 Common electrode, 6 Photoelectric conversion layer, 7 Pixel electrode, 9 Auxiliary capacitance electrode, 10 Gate insulating film, 11 Gate electrode, 12 Drain electrode, 13 Active layer , 14 region, 15, 16 insulating film, 19 source electrode, 101 lens material layer, 102 resist, 103 etching gas, 104 magnet, 105 high frequency power source, 106 chamber, 107 magnetron RIE apparatus, 108 lower electrode, 109 upper electrode, 110 Laminate, 140 Film base, 141 Primer, 142 Ink pan, 143 Application roll, 144 Impression roll, 145 Drying zone, 146, 148 Nip roll, 147 UV irradiation device, 149 Roll intaglio, 163 Opening, 164 Male, 165 166 Female type 167 resin, 170 upper heating plate, 174 lower heating plate, 181 upper electrode, 182 lower electrode, 183 glass electrode, 190 first container, 191 second container, 192, 193 solution, 194 third container, 195 mixing Liquid, 200 housing, 201 imaging panel, 202 display unit, 203 operation unit, 204 connector, 205 control circuit, 206 memory unit, 207 signal selection circuit, 208 scan drive circuit, 209 power supply unit, 211 TFT, 212 signal line, 213 scanning line, 214 reset line, 215 transistor, 216 signal converter, 217 register, 218 A / D converter, 220 subject, 221 radiation image detector, 222 radiation generator, 223 image processing unit, 224 information input unit, 225 Image display unit, 226 Image storage unit, 227 AD, 228 an image output unit, 229 CT, 1410 nozzle coating apparatus, 1411 UV-curable resin, 1412 shaped film sheet, 2210 MRI, 2211 FPD, 2212 external image storage device, 2213 an external image display device, 2214 network.

Claims (7)

A substrate, a photoelectric conversion layer that is an organic compound that generates charge by incidence of light on the first surface of the substrate, and a pixel electrode for collecting charges generated in the photoelectric conversion layer ,
An optical sensor comprising a condensing member for condensing incident light in the direction of the photoelectric conversion layer on a second surface facing the first surface of the substrate.   The auxiliary capacitance unit is provided on the first surface of the substrate, and the capacitance of the photoelectric conversion layer is smaller than the capacitance of the auxiliary capacitance unit. Optical sensor.   The optical sensor according to claim 1, wherein the pixel electrode is formed directly on the first surface of the substrate.   The optical sensor according to any one of claims 1 to 3, wherein the photoelectric conversion layer has a thickness of 20 nm to 200 nm.   5. An optical sensor array, wherein the optical sensors according to claim 1 are arranged in a lattice pattern.   An image sensor comprising the photosensor array according to claim 5.   An imaging device including the imaging device according to claim 6.

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