JP2006086493A - Photoelectric conversion film, photoelectric conversion element and imaging element, and method of applying electric field to them, and applied element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoconductive film in which the half-value width of an absorption is narrow and which has excellent color reproduction, a photoelectric conversion element and an imaging element (preferably color image sensor) and to further provide a photoconductive film which has a high photoelectric conversion efficiency and excellent durability, a photoelectric conversion element and an imaging element. <P>SOLUTION: The imaging element includes the photoelectric conversion film which has the laminate structure of a p type semiconductor layer and an n type semiconductor layer between a pair of electrodes. The imaging element includes an organic compound of p type semiconductor and n type semiconductor in which orientation controlling is performed at least one of the p type semiconductor and the n type semiconductor. Or, in the photoelectric conversion film having at least one organic dye compound, the organic dye compound is formed in a J meeting object or an angle of the spectral absorption transition dipole moment of the organic dye compound and the electrode flat surface of the photoelectric conversion element is 40° or less. The photoelectric conversion element and the imaging element, and a method of applying an electric field to them are provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photoelectric conversion film, a photoelectric conversion element having the photoelectric conversion film, a solid-state imaging element, a method of applying an electric field to these, and an applied element.

  The photoelectric conversion film is widely used for, for example, an optical sensor, and is particularly preferably used as a solid-state imaging element (light-receiving element) of an imaging apparatus (solid-state imaging apparatus) such as a television camera. As a material of a photoelectric conversion film used as a solid-state imaging element of an imaging device, an inorganic material film such as a Si film or an a-Se film is mainly used.

  Conventional photoelectric conversion films using these inorganic material films do not have a steep wavelength dependence on the photoelectric conversion film characteristics. For this reason, an image pickup apparatus using a photoelectric conversion film has a three-plate structure including a prism that separates incident light into three primary colors of red, green, and blue, and three photoelectric conversion films that are arranged at the subsequent stage of the prism. Things have become mainstream.

  However, this three-plate type imaging device cannot avoid an increase in size and mass due to its structure.

  In order to reduce the size and weight of the image pickup apparatus, it is not necessary to provide a spectroscopic prism, and a single plate structure with one light receiving element is desired. For example, red, green, and blue filters are used for the single plate light receiving element. An image pickup device having a structure in which the structure is arranged is studied, and as a material of the photoelectric conversion film, there are various kinds and characteristics, and it is also considered to use an organic material having advantages such as a large degree of freedom of processing shape, Japanese Unexamined Patent Application Publication No. 2003-158254 discloses a photoelectric conversion film with improved photosensitivity (sensitivity) and a light receiving element using the photoelectric conversion film. In this document, an organic material is used as the p-type semiconductor and the n-type semiconductor. However, in the example of the publication, polymethylphenylsilane (PMPS) is used as the p-type organic material, and 8-hydroxyquinoline is used as the n-type organic material. Only an example in which 5.0 parts by mass of coumarin 6 as an organic dye is added to 100 parts by mass of the above PMPS using an aluminum complex (Alq3) is described. The description in the paragraph also describes that the organic dye is preferably used in an amount of 0.1 to 50 parts by mass with respect to 100 parts by mass of the p-type or n-type organic material constituting the photoelectric conversion film. Or there is no description of using as an n-type organic material.

Further, in order to realize a reduction in size and weight of the imaging apparatus, it is not necessary to provide a spectroscopic prism, and a low-resolution stacked photoelectric conversion film is disclosed as a single-plate structure having one light receiving element. It is described in the gazette. In this document, for example, a preferable stacked photoelectric conversion film absorbs light of a wavelength of any one of the three primary colors of light and a light of a wavelength of another color. It is described that a color image having high sensitivity and resolution can be obtained by laminating a photoelectric conversion film having a function of absorbing and a photoelectric conversion film having a function of absorbing the remaining light of one color. .
However, in the example of the publication, a coumarin 6 / polysilane film having photosensitivity in the entire blue region of 500 nm or less and a ZnPc / Alq3 film having an absorption region in the blue region together with the red region are used as the photoelectric conversion film. 6 / Only the photoelectric conversion film having photosensitivity only in the substantially red region centering on 600 to 700 nm is described due to the filter function of the polysilane film.

  Japanese Patent Laid-Open No. 2003-332551 describes a multilayer photoconductive film similar to that of Japanese Patent Laid-Open No. 2003-234460. However, in the above Patent Documents 1 to 3, the orientation of the organic compound described below, the J aggregate of the organic dye compound, and the angle formed between the spectral absorption transition dipole moment of the dye compound and the electrode plane of the photoelectric conversion element Is not described at all.

On the other hand, as described in Non-Patent Document 1 (Surface, 31 (10) 40 (1993)), the orientation of the organic compound can be controlled by selecting the substrate and adjusting the deposition conditions. For example, the method of giving anisotropy to the organic compound which gives a rubbing process to the substrate surface and grows on it etc. is mentioned.
However, the structure depending on the substrate crystal is observed only at a thickness of at most a dozen layers, and when the film thickness is increased, a bulk crystal structure is taken. The photoconductive film preferably has a film thickness of 100 nm or more (100 layers or more as molecules) in order to increase the light absorption rate. Therefore, it is difficult to apply the above document to a photoconductive film. In the case of a photoconductive film, it is considered necessary to control the orientation by utilizing the interaction between organic compounds in addition to the substrate.

The J aggregate of the organic dye compound is described in Non-Patent Document 2, and an aggregate whose absorption shifts to a long wavelength with respect to the monomer (monomer) absorption that does not interact between the dyes is referred to as a J aggregate. Call it. In general, it is known that when a J aggregate is formed, the absorption width on the long wavelength side is smaller than that in the monomer state.
JP 2003-158254 A JP 2003-234460 A JP 2003-332551 A Surface, 1993, 31 (10), 40 James (The Theory of the Photographic Process) 4th edition, McMillan Publishing Company, 1977, Chapter 8, pages 214-222, The Theory of the Photographic Process.

  An object of the present invention is to provide a photoconductive film, a photoelectric conversion element, and an imaging element (preferably a color image sensor) that have a narrow half-width of absorption and excellent color reproduction, and have high photoelectric conversion efficiency and durability. Is to provide an excellent photoconductive film, photoelectric conversion element, and imaging element.

  The present invention is solved by the following means.

(1) A photoelectric conversion film having at least one organic dye compound, wherein the organic dye compound forms a J aggregate.
The dye compound forming the J aggregate is preferably 10 nm or more longer than the absorption maximum of the dye solution in the monomer state, and the dye compound forming the J aggregate The absorption width on the long wavelength side of the absorption of the J aggregate is preferably not more than twice the absorption width on the long wavelength side of the absorption of the dye solution in the monomer state.
(2) A photoelectric conversion film having at least one organic dye compound, wherein an angle formed by a spectral absorption transition dipole moment of the organic dye compound and a photoelectric conversion film plane is 40 ° or less. . The angle is preferably 15 ° or less.
(3) A photoelectric conversion element comprising the photoelectric conversion film according to (1) or (2) and a pair of electrodes sandwiching the photoelectric conversion film.
(4) An imaging device including the photoelectric conversion device according to (3).
(5) In an imaging device having a photoelectric conversion film in which a p-type semiconductor layer and an n-type semiconductor layer have a stacked structure between a pair of electrodes, orientation control is performed on at least one of the p-type semiconductor and the n-type semiconductor. An imaging device comprising the organic compound prepared.
(6) In an imaging device having a photoelectric conversion film having a mixed / dispersed (bulk heterojunction structure) layer of a p-type semiconductor and an n-type semiconductor between a pair of electrodes, at least one of the p-type semiconductor and the n-type semiconductor An image sensor comprising an organic compound whose orientation is controlled in the direction.
(7) In an imaging device having a p-type semiconductor layer, an n-type semiconductor layer between a pair of electrodes, and a photoelectric conversion film having a bulk heterojunction structure layer layer between them, of the p-type semiconductor and the n-type semiconductor The imaging device according to (6), comprising an organic compound whose orientation is controlled in at least one direction.
(8) The imaging device according to any one of (5) to (7), characterized in that an orientation-controlled organic compound is included in both the p-type semiconductor and the n-type semiconductor.
(9) The imaging device according to any one of (5) to (8), wherein the orientation-controlled organic compound is an organic dye.
(10) The image sensor according to (9), wherein the organic dye is a merocyanine dye.
(11) The photoelectric conversion film according to (1) or (2), the photoelectric conversion element according to (3), or (4), wherein the organic compound layer has a thickness of 30 nm to 300 nm. The imaging device according to any one of to (10).
(12) An imaging device, wherein two or more photoelectric conversion films according to any one of (1) to (11) are stacked.
(13) The image sensor according to (12), wherein the two or more layers of photoelectric conversion elements according to (12) include three layers of a blue photoelectric conversion element, a green photoelectric conversion element, and a red photoelectric conversion element. .
(14) The photoelectric conversion film according to (1) or (2), the photoelectric conversion element according to (3), or (4), wherein the p-type semiconductor or n-type semiconductor on the incident light side is colorless. The imaging device according to any one of to (13).
(15) When the spectral absorption maximum values are λmax1, λmax2, and λmax3 in the order of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element described in (13), λmax1 is 400 nm to 500 nm, and λmax2 is (13) The imaging device according to (13), wherein 500 nm to 600 nm and λmax3 are in the range of 600 nm to 700 nm.
(16) When the spectral sensitivity maximum values are Smax1, Smax2, and Smax3 in the order of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element described in (13), Smax1 is 400 nm to 500 nm, and Smax2 is The imaging device according to (13), wherein the imaging element has a range of 500 nm to 600 nm and Smax3 is in the range of 600 nm to 700 nm.
(17) The interval between the shortest wavelength and the longest wavelength that indicates 50% of the spectral maximum absorption of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to (13) is 120 nm or less, respectively. (13) The imaging device according to (13).
(18) The interval between the shortest wavelength and the longest wavelength that indicates 50% of the spectral maximum sensitivity of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to (13) is 120 nm or less, respectively. (13) The imaging device according to (13).
(19) The interval between the shortest wavelength and the longest wavelength that indicates 80% of the spectral maximum absorption of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to (13) is 20 nm or more and 100 nm or less, respectively. (13) The image pickup device according to (13).
(20) The interval between the shortest wavelength and the longest wavelength, which indicates 80% of the spectral maximum sensitivity of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element described in (13), is 20 nm or more and 100 nm or less, respectively. (13) The image pickup device according to (13).
(21) The interval between the shortest wavelength and the longest wavelength, which indicates 20% of the spectral maximum absorption of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element described in (13), is 180 nm or less, respectively. (13) The imaging device according to (13).
(22) The distance between the shortest wavelength and the longest wavelength, which indicates 20% of the spectral maximum sensitivity of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element described in (13), is 180 nm or less, respectively. (13) The imaging device according to (13).
(23) In the order of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element described in (13), the longest wavelengths indicating 50% of the spectral maximum absorption are 460 nm to 510 nm, 560 nm to 610 nm, and 640 nm, respectively. The imaging element according to (13), wherein the imaging element is from 730 to 730 nm.
(24) The longest wavelengths indicating 50% of the spectral maximum sensitivity in the order of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element described in (13) are 460 nm to 510 nm, 560 nm to 610 nm, and 640 nm, respectively. The imaging element according to (13), wherein the imaging element is from 730 to 730 nm.

(25) 10 V / m or more for the photoelectric conversion film according to (1) or (2), the photoelectric conversion element according to (3), or the imaging element according to any one of (4) to (24). A method of applying an electric field of 1 × 10 ¹² V / m or less, and an applied film or device.
(26) An element having at least two electromagnetic wave absorption / photoelectric conversion parts, wherein at least one of these parts is composed of the imaging device according to any one of (4) to (25).
(27) The element according to (26), wherein at least two electromagnetic wave absorption / photoelectric conversion sites have a laminated structure of at least two layers.
(28) The device according to (27), wherein the upper layer is composed of a portion capable of absorbing green light and performing photoelectric conversion.
(29) It has at least three electromagnetic wave absorption / photoelectric conversion parts, and at least one of these parts is composed of the image pickup device according to any one of claims 1 to 20. ).
(30) The device according to (29), wherein the upper layer is composed of a site capable of absorbing green light and performing photoelectric conversion.
(31) The element according to (29) or (30), wherein at least two electromagnetic wave absorption / photoelectric conversion sites are made of an inorganic layer.
(32) The element according to (29) or (30), wherein at least two electromagnetic wave absorption / photoelectric conversion sites are formed in a silicon substrate.
(33) The imaging according to any one of claims 4 to 24 according to any one of (26) to (32)] a method of applying an electric field of 10 V / m or more and 1 × 10 ¹² V / m or less to the device, And applied element.

(Hereafter, the same as the claim,
However, as a preferred embodiment of claim 1, [1] the absorption maximum value of the dye compound forming the J aggregate is 10 nm or more longer than the absorption maximum value of the dye solution in the monomer state. [2] The absorption width on the long wavelength side of the absorption of the J-aggregate of the dye compound forming the J-aggregate is 2 of the absorption width on the long wavelength side of the absorption of the dye solution in the monomer state. When it is characterized in that it is less than double, as a preferred embodiment of claim 4, [3] the angle formed by the spectral absorption transition dipole moment of the organic dye compound and the plane of the photoelectric conversion film is 15 ° or less, If you want to add. )

The photoconductive film, photoelectric conversion element, and imaging element of the present invention have a narrow half width of absorption and excellent color reproduction, and further have an effect of high photoelectric conversion efficiency and excellent durability. In addition to this, the BGR three-layer stacked solid-state imaging device has the following characteristics.
Due to the laminated structure, there is no moiré, no optical low-pass filter is required, so the resolution is high and there is no color blur. Further, signal processing is simple and no pseudo signal is generated. Furthermore, in the case of CMOS, pixel mixing is easy and partial reading is easy.
Since the aperture ratio is 100% and no microlens is required, there is no limitation on the exit pupil distance with respect to the imaging lens, and no shading. Therefore, it is suitable for a lens interchangeable camera, and in this case, the lens can be thinned.
Since there is no microlens, it is possible to seal the glass by filling the adhesive, reducing the package thickness, increasing the yield, and reducing the cost.
Because of the use of organic dyes, high sensitivity is obtained, no IR filter is required, and flare decreases.

One preferred embodiment of the present invention is an imaging device having a photoelectric conversion film having a p-type semiconductor layer, an n-type semiconductor layer (preferably a mixed / dispersed (bulk heterojunction structure) layer) between a pair of electrodes. In the photoelectric conversion film, an organic compound whose orientation is controlled in at least one of a p-type semiconductor and an n-type semiconductor is included. Preferably, both the p-type semiconductor and the n-type semiconductor have orientation control. It is characterized by containing a (possible) organic compound.
In the photoconductive film, the present invention compensates for the short carrier diffusion length of the organic layer by controlling the orientation of the organic compound in the organic layer, and improves the photoelectric conversion efficiency.

The present invention is characterized in that the orientation of the organic compound is more ordered than in a random state. If it is not random, the degree of order may be low or high, but high order is preferable.
As the organic compound used in the organic layer of the photoelectric conversion film, one having π-conjugated electrons is preferably used, but this π-electron plane is not perpendicular to the substrate (electrode substrate) but oriented at an angle close to parallel. The better it is. The angle with respect to the substrate is preferably 0 ° or more and 80 ° or less, more preferably 0 ° or more and 60 ° or less, further preferably 0 ° or more and 40 ° or less, and further preferably 0 ° or more and 20 ° or less. Particularly preferably, it is 0 ° or more and 10 ° or less, and most preferably 0 ° (that is, parallel to the substrate).

As described above, the organic compound layer whose orientation is controlled may be partially included in the entire organic layer. Preferably, the proportion of the portion whose orientation is controlled with respect to the entire organic layer is 10% or more, more preferably 30% or more, more preferably 50% or more, further preferably 70% or more, and particularly preferably 90%. Above, most preferably 100%.
The orientation of the organic compound can be controlled by selecting the substrate and adjusting the deposition conditions as described in Non-Patent Document 1. For example, the method of giving anisotropy to the organic compound which gives a rubbing process to the substrate surface and grows on it etc. is mentioned. However, the structure depending on the substrate crystal is observed only at a thickness of at most a dozen layers, and when the film thickness is increased, a bulk crystal structure is taken. In the photoelectric conversion element of the present invention, in order to increase the light absorption rate, it is preferable that the film thickness is 100 nm or more (100 layers or more as molecules). Therefore, it is necessary to control the orientation.

Any interaction force between organic compounds may be used. For example, as an intermolecular force, van der Waals force (more precisely, an orientation force acting between a permanent dipole and a permanent dipole) It can be expressed in terms of induced force acting between permanent dipole and induced dipole, and dispersion force acting between temporary dipole and induced dipole.), Charge transfer force (CT), Coulomb force (electrostatic force), hydrophobic bond Force, hydrogen bonding force, coordination bonding force and the like. Only one of these bonding forces can be used, or a plurality of arbitrary bonding forces can be used in combination.
Preferred are van der Waals force, charge transfer force, coulomb force, hydrophobic bond force and hydrogen bond force, more preferred are van der Waals force, coulomb force and hydrogen bond force, and particularly preferred is fan. -Del Waals force and Coulomb force, most preferably Van der Waals force.

  As one of the interactions between the organic compounds in the present invention, it is possible to use a covalent bond or a coordinate bond, and it is preferably a case where they are linked by a covalent bond ( It can also be regarded as a single coordination bond of intermolecular forces). In these cases, the covalent bond or the coordinate bond may be formed in advance or may be formed in the process of forming the organic layer.

Of the above intermolecular forces and covalent bonds, the intermolecular force is preferably used to control the orientation of the organic compound.
The attractive energy of these intermolecular forces is preferably 15 kJ / mol or more, more preferably 20 kJ / mol or more, and particularly preferably 40 kJ / mol or more. Although there is no upper limit in particular, Preferably it is 5000 kJ / mol or less, More preferably, it is 1000 kJ / mol or less.

  It is also possible to use a method in which dielectric anisotropy or polarization is imparted to an organic compound, and an electric field is applied during growth to align molecules.

As a preferable imaging device of the present invention, an imaging device having a photoelectric conversion film having a stacked structure of a p-type semiconductor layer and an n-type semiconductor layer between a pair of electrodes; a p-type semiconductor and n between the pair of electrodes. Imaging device having a photoelectric conversion film having a mixed / dispersed (bulk heterojunction structure) layer with a p-type semiconductor; a bulk heterojunction structure layer layer between a pn junction layer of a p-type semiconductor and an n-type semiconductor between a pair of electrodes An image sensor having a photoelectric conversion film.
In the case where the orientation of the organic compound of the present invention is controlled, it is more preferable that the heterojunction plane (for example, pn junction plane) is not parallel to the substrate. It is more preferable that the heterojunction plane is oriented not at a parallel to the substrate (electrode substrate) but at an angle close to perpendicular. The angle with respect to the substrate is preferably 10 ° or more and 90 ° or less, more preferably 30 ° or more and 90 ° or less, further preferably 50 ° or more and 90 ° or less, and further preferably 70 ° or more and 90 ° or less. Particularly preferably, it is 80 ° or more and 90 ° or less, and most preferably 90 ° or less (that is, perpendicular to the substrate).

The organic compound layer whose heterojunction surface is controlled as described above may be partially included in the entire organic layer. Preferably, the proportion of the portion whose orientation is controlled with respect to the entire organic layer is 10% or more, more preferably 30% or more, more preferably 50% or more, further preferably 70% or more, and particularly preferably 90%. Above, most preferably 100%. In such a case, the area of the heterojunction surface in the organic layer increases, the amount of carriers of electrons, holes, electron-hole pairs, etc. generated at the interface increases, and the photoelectric conversion efficiency can be improved.
As examples of specific drawings of the photoconductive film having the heterojunction layer (surface), those described in FIGS. 1 to 8 of JP-A-2003-298152 can be applied.

  As described above, in the photoconductive film (photoelectric conversion film) in which the orientations of both the heterojunction plane and the π-electron plane of the organic compound are controlled, the photoelectric conversion efficiency can be particularly improved.

  The present invention includes at least one organic photoelectric conversion film in which the orientation of these organic compounds is controlled, and preferably an imaging device in which at least two photoelectric conversion layers are stacked, and the orientation of the organic compounds is controlled. A device in which a voltage is applied to the organic photoelectric conversion film is preferable.

As one of the preferable embodiments of the present invention, the organic dye compound is present in a state where a J aggregate is formed in the photoelectric conversion film. Here, the state in which the dye forms a J-aggregate is a state in which the absorption maximum value is shifted to the long wavelength side from the absorption maximum value exhibited by the monomer state dye solution without interaction between the dyes. It means that there is. The shift width is preferably 10 nm or more, more preferably 25 nm or more, particularly preferably 50 nm or more, and most preferably 75 nm or more. The upper limit of the shift width is not particularly limited, but is preferably 200 nm or less, and more preferably 150 nm or less.
In general, it is known that when a dye forms a J-aggregate, the absorption maximum shifts to a longer wavelength side as compared with the monomer state. (The Theory of the Photographic Process, edited by TH James, 1977, Macmillan Publishing Co., Inc.) Thus, the J meeting can be defined by the above.
The absorption maximum value exhibited by the dye solution in the monomer state means the absorption maximum value in a dimethylformamide (DMF) solution having a dye concentration = 1 × 10 ⁻⁵ mol / l. When the dye does not dissolve in DMF, chloroform, methylene chloride, dimethyl sulfoxide, or methanol may be used as a solvent.

Further, when the absorption width on the long wavelength side of the absorption of the J aggregate of the dye formed in the photoelectric conversion film is not more than twice the absorption width on the long wavelength side of the absorption exhibited by the dye solution in the above monomer state Is preferred. More preferably, it is 1.5 times or less, particularly preferably 1 time or less, and most preferably 0.5 times or less. Here, the absorption width on the long wavelength side represents the energy width between the absorption maximum wavelength and the wavelength that is longer than the absorption maximum wavelength and exhibits half the absorption maximum. In general, it is known that when a J aggregate is formed, the absorption width on the long wavelength side is smaller than that in the monomer state. However, in the photoelectric conversion film, when the dye does not form a J-aggregate, the non-uniform interaction between the dyes becomes strong, so the absorption becomes broad, and the absorption width on the long wavelength side of the dye solution in the monomer state The absorption width is more than twice as large as that of. Therefore, in the present invention, the above is defined as a preferable absorption width of the J aggregate.
As described above, the organic dye compound layer in which the J aggregates are formed may be partially included in the entire organic layer. Preferably, the proportion of the portion whose orientation is controlled with respect to the entire organic layer is 10% or more, more preferably 30% or more, more preferably 50% or more, further preferably 70% or more, and particularly preferably 90%. Above, most preferably 100%.

  When the organic dye compound of the present invention forms a J aggregate in the photoelectric conversion film, in addition to the advantage that the half width of absorption of the obtained photoelectric conversion film is narrow and the color reproducibility is excellent, surprisingly, the photoelectric conversion efficiency Was found to be significantly higher. Surprisingly, it has been found that the durability of the photoelectric conversion film is also significantly improved.

Any force may be used as the interaction force between the organic dye compounds to form the J-aggregate of the organic dye compound. For example, as the intermolecular force, van der Waals force (more finely) Can be expressed in terms of an orientation force acting between a permanent dipole and a permanent dipole, an induced force acting between a permanent dipole and an induced dipole, and a dispersion force acting between a temporary dipole and an induced dipole). Force (CT), coulomb force (electrostatic force), hydrophobic bond force, hydrogen bond force, coordination bond force, and the like. Only one of these bonding forces can be used, or a plurality of arbitrary bonding forces can be used in combination.
Preferred are van der Waals force, charge transfer force, coulomb force, hydrophobic bond force and hydrogen bond force, more preferred are van der Waals force, coulomb force and hydrogen bond force, and particularly preferred is fan. -Del Waals force and Coulomb force, most preferably Van der Waals force.

  The attractive energy of these intermolecular forces is preferably 15 kJ / mol or more, more preferably 20 kJ / mol or more, and particularly preferably 40 kJ / mol or more. Although there is no upper limit in particular, it is preferably 5000 kJ / mol or less, more preferably 1000 kJ / mol or less.

[Associability of organic dye compounds]
We have found that the organic dye compound that forms a J aggregate in the photoelectric conversion film described above has a preferable range of associative properties represented by the following general formula (1). The value of the following formula (1) is preferably 1.5 or more, more preferably 2 or more, particularly preferably 3.5 or more, and most preferably 5 or more. Although there is no upper limit in particular, Preferably it is 20 or less, More preferably, it is 15 or less. It has been found that when the association property of the compound of the present invention is in these ranges, the durability of the photoelectric conversion film is improved in addition to the advantage that the photoelectric conversion efficiency of the obtained photoelectric conversion film is increased.

Explain about the meeting. In the present invention, the associative property is represented by (Agg).
The organic dye compound (DyeX) of the present invention preferably satisfies the following formula (1).
Formula (1) {Agg (DyeX) / Agg (Dye1)} ≧ 1.1
In the formula (1), Agg (Dye1) represents the following Dye1 associative property, and Agg (DyeX) represents the DyeX associative property.
Dye1

The dye has a property of associating (or also aggregating) due to the interaction between the dyes. Here, this associative property is defined by the ratio of the aggregate absorption to the monomer absorption of the following formula (B1).
Agg = A / M (B1)
In the formula (B1), A represents the absorption intensity of association absorption, and M represents the absorption intensity of monomer absorption. The measurement conditions are as follows.

Dye concentration: 1 × 10 ⁻⁵ mol / L
Solvent: Water Measurement temperature: 25 ° C
Under the above conditions, the absorption spectrum is measured to determine A and M.
In addition, when measurement is not possible due to the reason that the organic dye compound (DyeX) of the present invention is not dissolved under the above conditions, a mixed solvent appropriately added with an organic solvent such as methanol is used, and Dye1 is compared with Dye1. Can be measured. This is because equation (1) is defined by the relative value of the association property between DyeX and Dye1, and therefore the value of equation (1) does not change if the association property between DyeX and Dye1 is measured under the same conditions. .

The association absorption may be any absorption other than monomer absorption, and examples thereof include dimer absorption and H association absorption. Under these conditions, in most cases, as the absorption of association, dimer association absorption having a wavelength shorter than the monomer absorption maximum is exhibited. In this case, A means the absorption intensity (D) of dimer absorption.
However, under these conditions, H-association absorption or J-association absorption may be exhibited. For example, when three absorptions of dimer, H-association, and J-association absorption are exhibited as association absorption, A is the absorption intensity (D) of dimer absorption. , The sum of the absorption intensity (H) of H association absorption and the absorption intensity (J) of J association absorption.

  When DyeX has a group that can be dissociated at pH = 10 or less, the measurement is performed in a dissociated state. For example, any base such as NaOH equivalent to the dye (other KOH, triethylamine, etc. may be used. Also, the number of equivalents of these bases to the dye should be increased by the required amount depending on the dissociation group and the pKa of the base. Can be dissociated.

  For reference, the meeting is explained below. As for the association, for example, “The Theory of the Photographic Process” edited by James (The Theory of the Photographic Process), 4th edition, Macmillan Publishers, 1977, Chapter 8, 214. Pp. 222, “J-Aggregates” written by Takayoshi Kobayashi, World Scientific Publishing Co. Pte. Ltd., 1996, Chemical Physics Letters (Chemical Physics Letters) ), Vol. 6, 183 (1970), Zeitschiff fur Physikalische Chemie, Vol. 49, p. 324, (1941), Takaharu Matsubara, Toshio Tanaka, Journal of the Japan Photography Society, Vol. 52, No. 5, 395-399, 19 In 1989, Photographic Science and Engineering Vol. 18, No. 3, 335 (1974) and the like are described in detail.

  A monomer means a monomer. From the viewpoint of the absorption wavelength of the aggregate, an aggregate whose absorption shifts to a short wavelength with respect to the monomer absorption is referred to as an H aggregate (a dimer is specially called a dimer. An aggregate that shifts to a long wavelength is called a J aggregate. In general, it is known that when a J aggregate is formed, the absorption width on the long wavelength side is smaller than that in the monomer state.

[J-association]
We have further found that the organic dye compound of the present invention has a preferable range of J-association represented by the following general formula (2). The value of the following formula (2) is preferably 5 or more, more preferably 25 or more, further preferably 50 or more, particularly preferably 100 or more, and most preferably 150 or more. Although there is no upper limit in particular, Preferably it is 500 or less, More preferably, it is 250 or less.
When the J-association property of the organic dye compound of the present invention is in these ranges, in addition to the advantage that the half width of absorption of the obtained photoelectric conversion film is narrow, surprisingly, the photoelectric conversion efficiency is remarkably increased. I found it. Surprisingly, it has been found that the durability of the photoelectric conversion film is also significantly improved.

Explain about J-association. In the present invention, J association is represented by (J-Agg).
The dye compound (DyeX) of the present invention preferably satisfies the following formula (2).
Formula (2) {J-Agg (DyeX) / J-Agg (Dye1)} ≧ 1.1
In the formula (2), J-Agg (Dye1) represents the J-association property of Dye1 and J-association of J-Agg (DyeX) DyeX.

As described in the description of the above formula (1), the dye has a property of associating (or also called aggregation) by the interaction between the dyes. In this formula (2), in order to evaluate the J-association in particular among these associative properties, it is defined by the ratio of the absorption of the J aggregate to the absorption other than the J aggregate of the following formula (B2).
J-Agg = J / G (B2)
In the formula (B2), J represents the absorption intensity of J association absorption, and G represents the absorption intensity of absorption other than J association absorption. The measurement conditions are as follows.
Dye concentration: 1 × 10 ⁻⁵ mol / L
Solvent: 0.5% gelatin water (deionized gelatin is used as gelatin)
Temperature: 25 ° C
Under the above conditions, after standing for 3 hours, an absorption spectrum is measured at 25 ° C. to determine J and G.
In addition, when measurement is not possible due to the reason that the organic dye compound (DyeX) of the present invention does not dissolve under the above conditions, a mixed solvent appropriately added with an organic solvent such as methanol is used to compare DyeX with Dye1 for comparison. Can be measured. This is because equation (2) is defined by the relative value of the association between DyeX and Dye1, and therefore the value of equation (1) does not change if the association between DyeX and Dye1 is measured under the same conditions. .

Absorption other than J association may be any absorption other than J association absorption, and examples thereof include monomer absorption, dimer absorption, and H association absorption.
Under these conditions, in most cases, absorption other than J-association absorption shows monomer absorption and dimer absorption. In this case, G means the sum of the absorption intensity (M) of monomer absorption and the absorption intensity (D) of dimer absorption.

  When DyeX has a group that can be dissociated at pH = 10 or less, measurement is performed in a dissociated state. For example, any base such as NaOH equivalent to the dye (other KOH, triethylamine, etc. may be used. Also, the number of equivalents of these bases to the dye should be increased by the required amount depending on the dissociation group and the pKa of the base. Can be dissociated.

As one of preferred embodiments of the present invention, in a photoelectric conversion film containing an organic dye compound, we have found that there is a preferable range in the angle formed by the spectral absorption transition dipole moment of the dye compound and the plane of the photoelectric conversion film. . The angle formed by the spectral absorption transition dipole moment of the organic dye compound of the present invention and the photoelectric conversion film plane is preferably 40 ° or less, more preferably 30 ° or less, still more preferably 15 ° or less, and even more preferably 5 °. Hereinafter, it is particularly preferably 2 ° or less, most preferably 0 °. In the photoelectric conversion element, the preferable angle relationship can be replaced when the angle formed between the spectral absorption transition dipole moment of the organic dye compound and the electrode plane of the photoelectric conversion element is within the above range.
When the angle formed between the spectral absorption transition dipole moment of the organic dye compound of the present invention and the electrode plane of the photoelectric conversion element is within these ranges, the photoelectric conversion efficiency of the obtained photoelectric conversion film is remarkably increased, and it is surprising. In particular, it has been found that the light absorption rate is also significantly improved.
Conventionally, little attention has been paid to the orientation of the organic photoelectric conversion element in the film. The transition dipole moment of the dye molecule is in the major axis direction of the dye molecule, and when the dye in the photoelectric conversion film forms an angle with the electrode plane of the photoelectric conversion element, the transition dipole moment of the dye and the electrode of the photoelectric conversion element The plane is angled.
In the present invention, in order to improve the mobility of excitons and carriers in the dye generated by photoexcitation, the angle formed by the transition dipole moment of the dye and the electrode plane is an important parameter. It has been found that the photoelectric conversion efficiency is increased. When reviewing conventional organic photoelectric conversion elements from this viewpoint, it has become clear that there is no system in which the angle between the transition dipole moment of the dye and the electrode plane is nearly parallel, which is insufficient.
Furthermore, since light enters the photoelectric conversion element perpendicularly, the vibration plane of the electric field of the incident light is parallel to the photoelectric conversion element surface, that is, parallel to the electrode plane of the photoelectric conversion element. When the transition dipole moment of the dye and the electrode plane of the photoelectric conversion element are parallel to each other, it is clear that the light absorption efficiency is increased because it coincides with the electric field vibration plane of the incident light.

The transition dipole moment of the organic dye compound of the present invention can be determined, for example, by the following method. Experimental Physics Lecture 14, Kinoshita Yoshio edited by Kyoritsu Publishing Co., Ltd., 1986, measured the reflection spectrum of photoelectric conversion element using a 45-degree reflection optical system and an ultraviolet-visible spectrometer with a polarizer. To do. The reflection intensity (Ig (ν)) of light of p-polarized light and s-polarized light is measured in the range of 200 nm before and after the absorption wavelength of the dye. Further, the reflection intensity Iq (ν) of quartz as a standard material is measured by the same method. The refractive index n of quartz is obtained for each wave number (cm ^-1 ) by the following formula,
n ² = 1 + 1.2409 × 10 ¹⁰ / (106359 ² −ν ² )
From this, the reflectance (Rq (ν)) of quartz is
Rq (ν) = | (n−1) / (n + 1) | ²
The reflectance (Rg (ν)) of the photoelectric conversion element is
Rg (ν) = Rq (ν) × Ig (ν) / Iq (ν)
It can be obtained more.

The above reflectance measurement is performed for each of p-polarized light and s-polarized light, and the absorption spectrum for the p-polarized component and s-polarized component of the total absorption of the photoelectric conversion element by performing the Kramers-Kronig conversion (hereinafter referred to as KK conversion) on the reflected spectrum. Ap (ν) and As (ν) can be obtained. The KK conversion is described in the 4th edition, Experimental Chemistry Lecture 7 Spectroscopy II Hiroo Iguchi, Maruzen Co., Ltd., 1992, p. 320. By performing the above measurement with an element obtained by removing only the organic dye compound of the present invention from the photoelectric conversion element, absorption spectra A1p (ν) and A1s for the p-polarized component and the s-polarized component of the absorption of the element part other than the dye (ν) can be obtained similarly.
The absorption spectrum of the dye alone is
p polarization component A2p (ν) = Ap (ν) − A1p (ν)
s polarization component A2s (ν) = As (ν) − A1s (ν)
You can ask. From these measurements, the angle between the electrode plane and the transition dipole moment of the dye is θ2ps (ν) = tan ^-1 (A2p (ν) / A2s (ν) − 1 / √2)
It becomes. In the present invention, the angle formed by the electrode plane and the transition dipole moment of the dye is defined as θ2ps (ν) at the absorption maximum wavelength of the dye.

Alternatively, A2p (ν) and A2s (ν) can be obtained by integrating Ap (ν) and As (ν) with the wavelength change component of the first derivative with respect to wavelength. The angle between the electrode plane and the transition dipole moment of the dye can also be obtained in the same manner as described above using A2p (ν) and A2s (ν).
θ2ps (ν) = tan ⁻¹ (A12p (ν) / A12s (ν) − 1 / √2)
It becomes.

[Molecular weight]
We have found that the organic dye compounds of the present invention have a preferred molecular weight range. The molecular weight is preferably 300 or more and 1200 or less, more preferably 400 or more and 1000 or less, and particularly preferably 500 or more and 800 or less. When the molecular weight of the organic dye compound of the present invention is within these ranges, in addition to the advantage that the photoelectric conversion film can be easily formed by vacuum vapor deposition, the photoelectric conversion efficiency of the obtained photoelectric conversion film is high and excellent. Furthermore, it has been found that the variation in the light absorption rate and the photoelectric conversion efficiency between the pixels of the image sensor is reduced.

[Providing hydrophobicity]
We have found that the organic dye compounds of the present invention have a preferred hydrophilic / hydrophobic range. ClogP is preferably 2 or more and 10 or less, more preferably 3 or more and 8 or less, and particularly preferably 4 or more and 6 or less. When the hydrophilicity / hydrophobicity of the organic dye compound of the present invention is in these ranges, in addition to the advantage that the photoelectric conversion film can be easily formed by vacuum deposition or the like, the resulting photoelectric conversion film has high photoelectric conversion efficiency and is excellent. Furthermore, it has been found that the variation in the light absorption rate and the photoelectric conversion efficiency between the pixels of the image sensor is reduced. It has also been found that when the hydrophilicity / hydrophobicity of the organic dye compound of the present invention is within these ranges, the durability of the resulting film, particularly durability under high humidity conditions, is improved.

ClogP is used as a measure of the hydrophilicity / hydrophobicity of a compound.
Usually, hydrophilicity / hydrophobicity can be determined by the octanol / water partition coefficient (log P) of a compound. Specifically, it can be determined by actual measurement by the flask-shaking method described in the following document (1).
Reference (1): Structure-activity relationship social gathering (representative) Ikuo Fujita, edited by Chemistry Special Issue 122, “Structure-activity relationship of drugs-Guidelines for drug design and mechanism study”, Nanedo, 1979, Chapter 2 Pages 43-203. Especially on pages 86-89, Flask Shaking (Flash
Shaking) is described.

Since the measurement may be difficult when logP is 3 or more, a model for calculating logP can be used in the present invention. In the present invention, logP (hereinafter referred to as ClogP) based on this calculated value is used. Can be defined using.
For the purposes of the present invention, the logP calculation is calculated using Hansch-Leo's CLOGP program (Daylight Chemical Information Systems, USA) (version is algorithm = 4.01, fragment database = 17 (* 3)). If this software is not available, Applicants will provide their ClogP values for all specific compounds.
If the organic dye compound of the present invention can have multiple tautomers, ClogP can be calculated for each of these isomers, and if at least one of these values is within a particular range, Compounds are within the preferred scope of the present invention. Further, when there is no molecular fragment in the database of the above program, ClogP can be obtained by supplementing the data by actual measurement of the hydrophilicity / hydrophobicity. The organic dye compound of the present invention calculates ClogP based on the state at pH = 7.

〔potential〕
We have further found that the organic dye compounds of the present invention have a preferred potential range. The oxidation potential is preferably 0.3 V or more and 1.8 V or less (vs SCE), more preferably 0.5 V or more and 1.5 V or less, and particularly preferably 0.8 V or more and 1.3 V or less. The reduction potential is preferably −2 V or more and −0.5 V or less (vs SCE), more preferably −1.6 V or more and −0.8 V or less, and particularly preferably −1.4 V or more and −1 V or less.
It has been found that when the potential of the organic dye compound of the present invention is within these ranges, the durability of the photoelectric conversion film is improved in addition to the advantage that the photoelectric conversion efficiency of the obtained photoelectric conversion film is increased.

  Various methods can be used to measure the reduction potential and the oxidation potential. Preferably, the reduction potential and the oxidation potential are measured by phase discrimination type second harmonic AC polarography, and an accurate value can be obtained. The method of measuring the potential by the above-described phase discrimination type second harmonic alternating current polarography is described in Journal of Imaging Science, Volume 30, Page 27 (1986). Yes.

〔fluorescence〕
We have further found that the organic dye compounds of the present invention have a preferred fluorescence quantum yield and fluorescence lifetime range. The fluorescence quantum yield is preferably 0.1 or more and 1 or less, more preferably 0.5 or more and 1 or less, and particularly preferably 0.8 or more and 1 or less. The fluorescence lifetime is preferably 10 ps or more, more preferably 40 ps or more, and particularly preferably 160 ps or more. There is no particular upper limit, but it is preferably 1 ms or less.
When the fluorescence quantum yield and the fluorescence lifetime of the organic dye compound of the present invention are within these ranges, the photoelectric conversion film obtained has an improved photoelectric conversion efficiency, and the durability of the photoelectric conversion film is improved. I found.

  The fluorescence quantum yield can be measured by the method described in JP-A-63-138341. The method is described below. The fluorescence quantum yield in the dye film can be measured by basically the same method as in the case of the luminescence quantum yield of the solution. Usually, standard samples having known absolute quantum yields (for example, rhodamine B, quinine sulfate, 9 10-diphenylanthracene) and the like, and can be obtained through relative measurement comparing the incident light intensity and the light emission intensity of the sample under a fixed optical arrangement. Regarding this relative measurement method, for example, C.I. A. Parker and W.W. T.A. Rees, Analyst, 1960, 85, 587. The fluorescence quantum yield in the present invention may be either a solution state or a film state value, but is preferably a value in the film state.

  The fluorescence lifetime of the organic dye compound of the present invention can be measured by the method of Tadaaki Tani, Takeshi Suzuki, Klaus Chemnitz, Keitaro Yoshihara, The Journal of Physical Chemistry, 1992, Vol. 96, 78.

[Organic layer]
In the present invention, the organic layer will be described. The electromagnetic wave absorption / photoelectric conversion site comprising the organic layer of the present invention comprises an organic layer sandwiched between a pair of electrodes. The organic layer is formed by stacking or mixing parts that absorb electromagnetic waves, photoelectric conversion parts, electron transport parts, hole transport parts, electron blocking parts, hole blocking parts, crystallization prevention parts, electrodes and interlayer contact improvement parts, etc. The
The organic layer preferably contains an organic p-type compound or an organic n-type compound.
The organic layer preferably contains an organic p-type semiconductor (compound) and an organic n-type semiconductor (compound), and any of these may be used. Further, it may or may not have absorption in the visible and infrared regions, but it is preferable to use at least one compound (organic dye) having absorption in the visible region. Furthermore, a colorless p-type compound and an n-type compound may be used, and an organic dye may be added thereto.
In the case of a three-layer structure of p-type layer / bulk heterojunction layer / n-type layer, the p-type or n-type semiconductor (compound) on the incident light side is preferably colorless.

  The organic p-type semiconductor (compound) is a donor-type organic semiconductor (compound), which is mainly represented by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound. For example, triarylamine compound, benzidine compound, pyrazoline compound, styrylamine compound, hydrazone compound, triphenylmethane compound, carbazole compound, polysilane compound, thiophene compound, phthalocyanine compound, cyanine compound, merocyanine compound, oxonol compound, polyamine compound, indole Compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives), nitrogen-containing heterocyclic compounds The metal complex etc. which it has as can be used. Not limited to this, as described above, any organic compound having an ionization potential smaller than that of the organic compound used as the n-type (acceptor property) compound may be used as the donor organic semiconductor.

  Organic n-type semiconductors (compounds) are acceptor organic semiconductors (compounds), which are mainly represented by electron-transporting organic compounds and refer to organic compounds that easily accept electrons. More specifically, the organic compound having the higher electron affinity when two organic compounds are used in contact with each other. Therefore, as the acceptor organic compound, any organic compound can be used as long as it is an electron-accepting organic compound. For example, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives), 5- to 7-membered heterocyclic compounds containing nitrogen atoms, oxygen atoms, and sulfur atoms (E.g. pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole, benzimidazole, benzotriazole, Benzoxazole, benzothiazole, carbazole, purine, triazolopyridazine, triazolopyrimidine, tetrazaindene, o Metal complexes having ligands such as saziazole, imidazopyridine, pyralidine, pyrrolopyridine, thiadiazolopyridine, dibenzazepine, tribenzazepine), polyarylene compounds, fluorene compounds, cyclopentadiene compounds, silyl compounds, and nitrogen-containing heterocyclic compounds. Etc. Note that the present invention is not limited thereto, and as described above, any organic compound having an electron affinity higher than that of the organic compound used as the donor organic compound may be used as the acceptor organic semiconductor.

Any p-type organic dye or n-type organic dye may be used, but preferably a cyanine dye, styryl dye, hemicyanine dye, merocyanine dye (including zero methine merocyanine (simple merocyanine)), three nucleus Merocyanine dye, 4-nuclear merocyanine dye, rhodacyanine dye, complex cyanine dye, complex merocyanine dye, allopolar dye, oxonol dye, hemioxonol dye, squalium dye, croconium dye, azamethine dye, coumarin dye, arylidene dye, anthraquinone dye, triphenyl Methane dye, azo dye, azomethine dye, spiro compound, metallocene dye, fluorenone dye, fulgide dye, perylene dye, phenazine dye, phenothiazine dye, quinone dye, indigo Dye, diphenylmethane dye, polyene dye, acridine dye, acridinone dye, diphenylamine dye, quinacridone dye, quinophthalone dye, phenoxazine dye, phthaloperylene dye, diketopyrrolopyrrole dye, dioxane dye, porphyrin dye, chlorophyll dye, phthalocyanine dye, metal complex And dyes and condensed aromatic carbocyclic dyes (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives).
The film formed by the p-type organic dye and the n-type organic dye may be in an amorphous state, a liquid crystal state, or a crystalline state. When used in a crystalline state, it is preferable to use a pigment.

Next, the metal complex compound will be described. The metal complex compound is a metal complex having a ligand having at least one nitrogen atom or oxygen atom or sulfur atom coordinated to the metal, and the metal ion in the metal complex is not particularly limited, but preferably beryllium ion, magnesium Ion, aluminum ion, gallium ion, zinc ion, indium ion, or tin ion, more preferably beryllium ion, aluminum ion, gallium ion, or zinc ion, and still more preferably aluminum ion or zinc ion. There are various known ligands contained in the metal complex. For example, “Photochemistry and Photophysics of Coordination Compounds” published by Springer-Verlag H. Yersin in 1987, “Organometallic Chemistry— Examples of the ligands described in “Basics and Applications—” published by Akio Yamamoto, 1982, etc.
The ligand is preferably a nitrogen-containing heterocyclic ligand (preferably having 1 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 3 to 15 carbon atoms, and a monodentate ligand. Or a bidentate or higher ligand, preferably a bidentate ligand such as a pyridine ligand, a bipyridyl ligand, a quinolinol ligand, a hydroxyphenylazole ligand (hydroxyphenyl) Benzimidazole, hydroxyphenylbenzoxazole ligand, hydroxyphenylimidazole ligand)), alkoxy ligand (preferably 1-30 carbon atoms, more preferably 1-20 carbon atoms, particularly preferably carbon 1-10, for example, methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc.), aryloxy ligands Preferably it has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 1-naphthyloxy, 2-naphthyloxy, 2,4,6-trimethylphenyl Oxy, 4-biphenyloxy, etc.), heteroaryloxy ligands (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as pyridyl. Oxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc.), alkylthio ligands (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio ligand (preferably having 6 to 30 carbon atoms, more preferred) Has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, etc.), a heterocyclic substituted thio ligand (preferably 1 to 30 carbon atoms, more preferably 1 to carbon atoms). 20, particularly preferably 1 to 12 carbon atoms, such as pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio), or siloxy ligand (preferably Has 1 to 30 carbon atoms, more preferably 3 to 25 carbon atoms, particularly preferably 6 to 20 carbon atoms, and examples thereof include a triphenylsiloxy group, a triethoxysiloxy group, and a triisopropylsiloxy group. More preferably a nitrogen-containing heterocyclic ligand, an aryloxy ligand, a heteroaryloxy group, or a siloxy ligand, Preferably, a nitrogen-containing heterocyclic ligand, an aryloxy ligand, or a siloxy ligand is used.

  Cyanine dye, styryl dye, hemicyanine dye, merocyanine dye, trinuclear merocyanine dye, tetranuclear merocyanine dye having a high degree of freedom in adjusting the absorption wavelength for use as a color imaging device, which is one of the objects of the present invention A methine dye such as rhodacyanine dye, complex cyanine dye, complex merocyanine dye, allopolar dye, oxonol dye, hemioxonol dye, squalium dye, croconium dye or azamethine dye can be preferably used. More preferred are merocyanine dyes, trinuclear merocyanine dyes, and tetranuclear merocyanine dyes, and more preferred are merocyanine dyes.

Details of these methine dyes are described in the following dye literature.
[Dye literature]
FMHarmer, `` Heterocyclic Compounds-Cyanine Dyes and Related Compounds, '' John Wiley & Sons -New York, London, 1964, DMSturmer, "Heterocyclic Compounds-Special topics in cyclic chemistry", Chapter 18. , Pp. 482-515, John Wiley & Sons-New York, London, 1977, "Rodd's Chemistry of Carbon Compounds" 2nd.Ed.vol.IV, part B, 1977, Chapter 15, 369 from 422 pp., Elsevier Science Public Company, Inc. (Elsevier Science Publishing Company Inc.) published by, New York, and so on.

Further description is made from Research Disclosure (RD) 17643, pages 23 to 24, RD18716, page 648, right column to page 649, right column, RD308119, page 996, right column to page 998, right column, European Patent No. 0565096A1. Those described on page 65, lines 7 to 10 can be preferably used. Also, U.S. Pat. No. 5,747,236 (especially pages 30-39), U.S. Pat. No. 5,994,051 (especially pages 32-43), U.S. Pat. No. 5,340,694 (especially 21-58, provided that the number of n ₁₂ , n ₁₅ , n ₁₇ , n ₁₈ is not limited in the dyes shown in (XI), (XII), (XIII), and is an integer of 0 or more (preferably 4 or less), and a dye having a partial structure or structure shown in the general formula and specific examples can also be preferably used.
The blending ratio of the p-type organic semiconductor and the n-type organic semiconductor in the intermediate layer of the photoelectric conversion film can be appropriately set within a range of 0.1: 99.9 to 99.9 to 0.1 by mass ratio. .

[Electron transporting materials]
In the photoelectric conversion film of the present invention, the organic material (n-type compound) having an electron transporting property preferably has an ionization potential larger than 6.0 eV, and may be represented by the following general formula (X). preferable.
Formula (X) L- (A) m
(In the formula, A represents a heterocyclic group in which two or more aromatic heterocycles are condensed, and the heterocyclic group represented by A may be the same or different. M represents an integer of 2 or more. L Represents a linking group.)
Details and preferred ranges of these organic materials having electron transport properties are described in detail in Japanese Patent Application No. 2004-082002.
When these electron transporting organic materials are used, the photoelectric conversion efficiency of the obtained photoelectric conversion film is remarkably increased.

(Formation method of organic layer)
The layer containing these organic compounds is formed by a dry film formation method or a wet film formation method. Specific examples of the dry film forming method include a vacuum vapor deposition method, a sputtering method, an ion plating method, a physical vapor deposition method such as an MBE method, or a CVD method such as plasma polymerization. As the wet film forming method, a casting method, a spin coating method, a dipping method, an LB method, or the like is used.
In the case of using a polymer compound as at least one of the p-type semiconductor (compound) or the n-type semiconductor (compound), it is preferable to form the film by a wet film forming method that is easy to create. When a dry film formation method such as vapor deposition is used, it is difficult to use a polymer because it may be decomposed, and an oligomer thereof can be preferably used instead.
On the other hand, in the present invention, when a low molecule is used, a dry film forming method is preferably used, and a vacuum deposition method is particularly preferably used. The vacuum deposition method is basically based on the method of heating compounds such as resistance heating deposition method, electron beam heating deposition method, shape of deposition source such as crucible, boat, etc., vacuum degree, deposition temperature, substrate temperature, deposition rate, etc. It is a parameter. In order to enable uniform deposition, it is preferable to perform deposition by rotating the substrate. The degree of vacuum is preferably higher, and vacuum deposition is performed at 10 ⁻⁴ Torr or less, preferably 10 ⁻⁶ Torr or less, particularly preferably 10 ⁻⁸ Torr or less. It is preferable that all steps during the deposition be performed in a vacuum, and basically the compound is not directly in contact with oxygen and moisture in the outside air. The above-described conditions of vacuum deposition affect the crystallinity, amorphousness, density, density, etc. of the organic film, and therefore must be strictly controlled. It is preferable to perform PI or PID control of the deposition rate using a film thickness monitor such as a quartz crystal resonator or an interferometer. When two or more kinds of compounds are vapor-deposited at the same time, a co-evaporation method, a flash vapor deposition method, or the like can be preferably used.

[Absorption wavelength regulation]
We have further found that the organic dye compounds of the present invention have a preferred spectral absorption wavelength and spectral sensitivity range.
In the present invention, a BGR photoelectric conversion film with good color reproduction, that is, a photoelectric conversion element in which three layers of a blue photoelectric conversion film, a green photoelectric conversion film, and a red photoelectric conversion film are stacked can be preferably used. Each photoelectric conversion film preferably has the following spectral absorption and / or spectral sensitivity characteristics.
When the spectral absorption maximum values are λmax1, λmax2, and λmax3 in the order of BGR, and the spectral sensitivity maximum values are Smax1, Smax2, and Smax3 in the order of BGR, λmax1 and Smax1 are preferably 400 nm to 500 nm, more preferably 420 nm or more. It is a case where it is 480 nm or less, particularly preferably in the range of 430 nm or more and 470 nm or less. λmax2 and Smax2 are preferably in the range of 500 nm to 600 nm, more preferably 520 nm to 580 nm, and particularly preferably 530 nm to 570 nm. λmax3 and Smax3 are preferably 600 nm to 700 nm, more preferably 620 nm to 680 nm, and particularly preferably 630 nm to 670 nm.

In addition, when the photoelectric conversion film of the present invention has a laminated structure of three or more layers, the shortest wavelength and the longest wavelength exhibiting 50% of the spectral maximum absorption of λmax1, λmax2, and λmax3 and the spectral maximum sensitivity of Smax1, Smax2, and Smax3, respectively. The wavelength interval is preferably 120 nm or less, more preferably 100 nm or less, particularly preferably 80 nm or less, and most preferably 70 nm or less.
Further, the interval between the shortest wavelength and the longest wavelength that shows 80% of the spectral maximum absorption of λmax1, λmax2, and λmax3 and the spectral maximum sensitivity of Smax1, Smax2, and Smax3 is preferably 20 nm or more, preferably 100 nm or less, and more preferably. Is 80 nm or less, particularly preferably 50 nm or less.
Further, the interval between the shortest wavelength and the longest wavelength that shows 20% of the spectral maximum absorption of λmax1, λmax2, and λmax3 and the spectral maximum sensitivity of Smax1, Smax2, and Smax3 is preferably 180 nm or less, more preferably 150 nm or less, and particularly preferably. Is 120 nm or less, most preferably 100 nm or less.
Also, on the long wave side of λmax1, λmax2, λmax3 and Smax1, Smax2, Smax3, the longest wavelength showing the spectral maximum absorption of λmax1, λmax2, λmax3 and 50% of the spectral maximum of Smax1, Smax2, Smax3, λmax1 and Smax1 are preferably 460 to 510 nm, λmax2 and Smax2 are preferably 560 to 610 nm, and λmax3 and Smax3 are preferably 640 to 730 nm.
When the spectral absorption wavelength and spectral sensitivity range of the compound of the present invention are within these ranges, the color reproducibility of the color image obtained by the imaging device can be improved.

[Thickness regulation of organic dye layer]
When the photoelectric conversion film of the present invention is used as a color imaging device (image sensor), the light absorption rate of each of the organic dye layers of the B, G, and R layers is preferably 50% or more, more preferably 70% or more, and particularly preferably. Is preferably 90% (absorbance = 1) or more, and most preferably 99% or more in order to improve the photoelectric conversion efficiency and to improve color separation without passing excess light through the lower layer. Therefore, the thickness of the organic dye layer is preferably as large as possible in terms of light absorption, but considering the ratio contributing to charge separation, the film thickness of the organic dye layer in the present invention is preferably 30 nm to 300 nm, more preferably 50 nm. The thickness is from 250 nm to 250 nm, particularly preferably from 60 nm to 200 nm, and most preferably from 80 nm to 130 nm.

[Apply voltage]
When a voltage is applied to the photoelectric conversion film of the present invention, it is preferable in terms of improving the photoelectric conversion efficiency. The applied voltage may be any voltage, but the required voltage varies depending on the film thickness of the photoelectric conversion film. That is, the photoelectric conversion efficiency improves as the electric field applied to the photoelectric conversion film increases, but the applied electric field increases as the film thickness of the photoelectric conversion film decreases even at the same applied voltage. Therefore, when the photoelectric conversion film is thin, the applied voltage may be relatively small. The electric field applied to the photoelectric conversion film is preferably 10 V / m or more, more preferably 1 × 10 ³ V / m or more, more preferably 1 × 10 ⁵ V / m or more, and particularly preferably 1 × 10 ⁶ V / m. m or more, most preferably 1 × 10 ⁷ V / m or more. The upper limit is not particularly since current even in a dark place when the electric field too added flows undesirable, 1 × preferably 10 ¹² V / m or less, preferably more 1 × 10 ⁹ V / m or less.

[General requirements]
In the present invention, it is preferable to use a structure in which at least two or more photoelectric conversion elements are stacked, more preferably three or four layers, and particularly preferably three layers.
In the present invention, these photoelectric conversion elements can be preferably used as an image sensor, particularly preferably as a solid-state image sensor.
Moreover, in this invention, the case where a voltage is applied to these photoelectric conversion films, photoelectric conversion elements, and image sensors is preferable.
The photoelectric conversion element in the present invention is preferably a case where a p-type semiconductor layer and an n-type semiconductor layer have a photoelectric conversion film having a stacked structure between a pair of electrodes. Preferably, at least one of the p-type and n-type semiconductors contains an organic compound, and more preferably, both the p-type and n-type semiconductors contain an organic compound.

[Bulk heterojunction structure]
In the present invention, a p-type semiconductor layer and an n-type semiconductor layer are provided between a pair of electrodes, and at least one of the p-type semiconductor and the n-type semiconductor is an organic semiconductor, and these semiconductor layers It is preferable to contain a photoelectric conversion film (photosensitive layer) having a bulk heterojunction structure layer containing the p-type semiconductor and the n-type semiconductor as an intermediate layer. In such a case, in the photoelectric conversion film, by incorporating a bulk heterojunction structure in the organic layer, the disadvantage that the carrier diffusion length of the organic layer is short can be compensated, and the photoelectric conversion efficiency can be improved.
The bulk heterojunction structure is described in detail in Japanese Patent Application No. 2004-080639.

[Tandem structure]
In the present invention, a photoelectric conversion film (photosensitive layer) having a structure having two or more repeating structures (tandem structures) of a pn junction layer formed of a p-type semiconductor layer and an n-type semiconductor layer between a pair of electrodes ), And more preferably, a thin layer of a conductive material is inserted between the repetitive structures. The number of repeating structures (tandem structures) of the pn junction layer may be any number, but is preferably 2 or more and 10 or less, more preferably 2 or more and 5 or less, and particularly preferably 2 in order to increase the photoelectric conversion efficiency. Or 3, most preferably 3. Silver or gold is preferable as the conductive material, and silver is most preferable.
In the present invention, the semiconductor having a tandem structure may be an inorganic material, but is preferably an organic semiconductor, and more preferably an organic dye.
The tandem structure is described in detail in Japanese Patent Application No. 2004-079930.

[Laminated structure]
As one preferable aspect of the present invention, when no voltage is applied to the photoelectric conversion film, it is preferable that at least two photoelectric conversion films are laminated. There are no particular limitations on the multilayer imaging device, and any of those used in this field can be applied. However, a BGR three-layer structure is preferred, and a preferred example of the BGR multilayer structure is shown in FIG.
Next, the solid-state imaging device according to the present invention has, for example, a photoelectric conversion film as shown in FIG. In the solid-state imaging device as shown in FIG. 1, a stacked photoelectric conversion film is provided on the scanning circuit unit. The scanning circuit unit can appropriately adopt a configuration in which a MOS transistor is formed on a semiconductor substrate for each pixel unit, or a configuration having a CCD as an image sensor.
For example, in the case of a solid-state imaging device using a MOS transistor, charges are generated in the photoelectric conversion film by incident light transmitted through the electrodes, and the charges are generated by an electric field generated between the electrodes by applying a voltage to the electrodes. It travels to the electrode through the photoelectric conversion film, and further moves to the charge storage part of the MOS transistor, and charges are stored in the charge storage part. The charge accumulated in the charge accumulation unit moves to the charge readout unit by switching of the MOS transistor, and is further output as an electric signal. Thereby, a full-color image signal is input to the solid-state imaging device including the signal processing unit.
As these laminated image pickup devices, solid color image pickup devices represented by FIG. 2 of JP-A-58-103165, FIG. 2 of JP-A-58-103166, and the like can also be applied.

  The method described in JP-A-2002-83946 (see FIGS. 7 to 23 and paragraph numbers 0026 to 0038 of the same publication) can be applied to the manufacturing process of the above-described multilayer image sensor, preferably a three-layer image sensor.

(Photoelectric conversion element)
The photoelectric conversion element of the preferable aspect of this invention is demonstrated below.
The photoelectric conversion element of the present invention comprises an electromagnetic wave absorption / photoelectric conversion site and a charge accumulation / transfer / readout site for charges generated by photoelectric conversion.
In the present invention, the electromagnetic wave absorption / photoelectric conversion site has a laminated structure of at least two layers capable of absorbing and photoelectrically converting at least blue light, green light, and red light. The blue light absorbing layer (B) can absorb light of at least 400 nm or more and 500 nm or less, and preferably the peak wavelength absorptance in the wavelength region is 50% or more. The green light absorbing layer (G) can absorb light of at least 500 nm to 600 nm, and preferably the peak wavelength absorptance in the wavelength region is 50% or more. The red light absorbing layer (R) can absorb light of at least 600 nm or more and 700 nm or less, and preferably has an absorptance of a peak wavelength in the wavelength region of 50% or more. The order of these layers may be any order, and in the case of a three-layer laminated structure, the order of BGR, BRG, GBR, GRB, RBG, and RGB is possible from the upper layer (light incident side). Preferably, the uppermost layer is G. In the case of a two-layer structure, when the upper layer is the R layer, the lower layer is the same BG layer, when the upper layer is the B layer, the lower layer is the same planar GR layer, and when the upper layer is the G layer, the lower layer is the same A BR layer is formed in a planar shape. Preferably, the upper layer is a G layer and the lower layer is a BR layer on the same plane. Thus, when two light absorption layers are provided on the same plane of the lower layer, it is preferable to provide, for example, a mosaic layer on the upper layer or a filter layer capable of color separation between the upper layer and the lower layer. In some cases, it is possible to provide a fourth layer or more as a new layer or in the same plane.
In the present invention, the charge accumulation / transfer / readout part is provided under the electromagnetic wave absorption / photoelectric conversion part. It is preferable that the electromagnetic wave absorption / photoelectric conversion site in the lower layer also serves as a charge storage / transfer / readout site.
In the present invention, the electromagnetic wave absorption / photoelectric conversion site is composed of an organic layer, an inorganic layer, or a mixture of an organic layer and an inorganic layer. The organic layer may form a B / G / R layer, or the inorganic layer may form a B / G / R layer. A mixture of an organic layer and an inorganic layer is preferred. In this case, basically, when the organic layer is one layer, the inorganic layer is one or two layers, and when the organic layer is two layers, the inorganic layer is one layer. When the organic layer and the inorganic layer are one layer, the inorganic layer forms electromagnetic wave absorption / photoelectric conversion sites of two or more colors on the same plane. Preferably, the upper layer is an organic layer and is a G layer, and the lower layer is an inorganic layer and is an order of B layer and R layer from the top. In some cases, it is possible to provide a fourth layer or more as a new layer or in the same plane. In the case where the organic layer forms a B / G / R layer, a charge accumulation / transfer / readout portion is provided thereunder. When an inorganic layer is used as the electromagnetic wave absorption / photoelectric conversion site, this inorganic layer also serves as a charge accumulation / transfer / readout site.

In the present invention, one particularly preferable aspect among the elements described above is as follows.
This is the case of having at least two electromagnetic wave absorption / photoelectric conversion sites, and at least one of these sites is the element (imaging device) of the present invention.
Furthermore, it is preferable that the element has a laminated structure in which at least two electromagnetic wave absorption / photoelectric conversion sites have at least two layers. Furthermore, it is preferable that the upper layer is an element composed of a part capable of absorbing green light and performing photoelectric conversion.
Particularly preferably, there are at least three electromagnetic wave absorption / photoelectric conversion sites, and at least one of these sites is the element (imaging device) of the present invention.
Furthermore, it is preferable that the upper layer is an element composed of a part capable of absorbing green light and performing photoelectric conversion. Further, at least two of the three electromagnetic wave absorption / photoelectric conversion sites are inorganic layers (preferably formed in a silicon substrate).

(electrode)
The electromagnetic wave absorption / photoelectric conversion site made of the organic layer of the present invention is sandwiched between a pair of electrodes, each of which forms a pixel electrode and a counter electrode. The lower layer is preferably a pixel electrode.
The counter electrode is preferably a material that can take out holes from the hole transport photoelectric conversion film or the hole transport layer, and can use a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof. . The pixel electrode preferably takes out electrons from the electron transporting photoelectric conversion layer or the electron transporting layer. Adhesion with adjacent layers such as the electron transporting photoelectric conversion layer and the electron transporting layer, electron affinity, ionization potential, stability, etc. Selected in consideration of Specific examples of these include conductive metal oxides such as tin oxide, zinc oxide, indium oxide and indium tin oxide (ITO), or metals such as gold, silver, chromium and nickel, and these metals and conductive metal oxides. Inorganic conductive materials such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene and polypyrrole, silicon compounds and laminates of these with ITO, etc. In particular, ITO and IZO are preferable from the viewpoints of productivity, high conductivity, transparency, and the like. Although the film thickness can be appropriately selected depending on the material, it is usually preferably in the range of 10 nm to 1 μm, more preferably 30 nm to 500 nm, and still more preferably 50 nm to 300 nm.

Various methods are used for manufacturing the pixel electrode and the counter electrode depending on the material. For example, in the case of ITO, electron beam method, sputtering method, resistance heating vapor deposition method, chemical reaction method (sol-gel method, etc.), dispersion of indium tin oxide A film is formed by a method such as application of an object. In the case of ITO, UV-ozone treatment, plasma treatment, etc. can be performed.
In the present invention, it is preferable to produce the transparent electrode film free of plasma. By creating a transparent electrode film free of plasma, the influence of plasma on the substrate can be reduced, and the photoelectric conversion characteristics can be improved. Here, plasma free means that no plasma is generated during the formation of the transparent electrode film, or the distance from the plasma generation source to the substrate is 2 cm or more, preferably 10 cm or more, more preferably 20 cm or more. It means a state in which the plasma that reaches is reduced.

Examples of an apparatus that does not generate plasma during the formation of the transparent electrode film include an electron beam vapor deposition apparatus (EB vapor deposition apparatus) and a pulse laser vapor deposition apparatus. Regarding EB deposition equipment or pulse laser deposition equipment, “Surveillance of Transparent Conductive Films” supervised by Yutaka Sawada (published by CMC, 1999), “New Development of Transparent Conductive Films II” by Yutaka Sawada (published by CMC, 2002) ), "Transparent conductive film technology" by the Japan Society for the Promotion of Science (Ohm Co., 1999), and references and the like appended thereto can be used. Hereinafter, a method for forming a transparent electrode film using an EB vapor deposition apparatus is referred to as an EB vapor deposition method, and a method for forming a transparent electrode film using a pulse laser vapor deposition apparatus is referred to as a pulse laser vapor deposition method.
For an apparatus that can realize a state in which the distance from the plasma generation source to the substrate is 2 cm or more and the arrival of plasma to the substrate is reduced (hereinafter referred to as a plasma-free film forming apparatus), for example, an opposed target sputtering Equipment, arc plasma deposition, etc. are considered, and these are supervised by Yutaka Sawada "New development of transparent conductive film" (published by CMC, 1999), and supervised by Yutaka Sawada "New development of transparent conductive film II" (published by CMC) , 2002), “Transparent conductive film technology” (Ohm, 1999) by the Japan Society for the Promotion of Science, and references and the like attached thereto can be used.

The electrode of the organic electromagnetic wave absorption / photoelectric conversion site of the present invention will be described in more detail. The photoelectric conversion film of the organic layer is sandwiched between the pixel electrode film and the counter electrode film, and can include an interelectrode material or the like. The pixel electrode film is an electrode film formed above the substrate on which the charge accumulation / transfer / readout part is formed, and is usually divided into pixels. This is to obtain an image by reading out the signal charges converted by the photoelectric conversion film on a charge storage / transfer / signal readout circuit substrate for each pixel.
The counter electrode film has a function of discharging a signal charge having a polarity opposite to that of the signal charge by sandwiching the photoelectric conversion film together with the pixel electrode film. Since the discharge of the signal charge does not need to be divided between the pixels, the counter electrode film can be commonly used between the pixels. Therefore, it may be called a common electrode film (common electrode film).

The photoelectric conversion film is located between the pixel electrode film and the counter electrode film. The photoelectric conversion function functions by the photoelectric conversion film, the pixel electrode film, and the counter electrode film.
As an example of the configuration of the photoelectric conversion film stack, first, when there is one organic layer stacked on the substrate, the pixel electrode film (basically a transparent electrode film), the photoelectric conversion film, the counter electrode film (transparent electrode film) from the substrate ) In order, but is not limited thereto.
Further, when two organic layers are stacked on the substrate, for example, from the substrate to the pixel electrode film (basically a transparent electrode film), a photoelectric conversion film, a counter electrode film (transparent electrode film), an interlayer insulating film, a pixel electrode A configuration in which a film (basically a transparent electrode film), a photoelectric conversion film, and a counter electrode film (transparent electrode film) are sequentially stacked is exemplified.

The material of the transparent electrode film constituting the photoelectric conversion site of the present invention is preferably one that can be formed by a plasma-free film forming apparatus, an EB vapor deposition apparatus, and a pulse laser vapor deposition apparatus. For example, a metal, an alloy, a metal oxide, a metal nitride, a metal boride, an organic conductive compound, a mixture thereof, and the like are preferable. Specific examples include tin oxide, zinc oxide, indium oxide, and indium zinc oxide. (IZO), indium tin oxide (ITO), conductive metal oxides such as indium tungsten oxide (IWO), metal nitrides such as titanium nitride, metals such as gold, platinum, silver, chromium, nickel, aluminum, and these A mixture or laminate of a metal and a conductive metal oxide, an inorganic conductive material such as copper iodide or copper sulfide, an organic conductive material such as polyaniline, polythiophene or polypyrrole, a laminate of these and ITO, Etc. Also, supervised by Yutaka Sawada “New Development of Transparent Conductive Film” (published by CMC, 1999), supervised by Yutaka Sawada “New Development of Transparent Conductive Film II” (published by CMC, 2002), “Transparent by Japan Society for the Promotion of Science” Those described in detail in “Technology of Conductive Film” (Ohm Co., 1999) may be used.
Particularly preferable materials for the transparent electrode film are ITO, IZO, SnO ₂ , ATO (antimony-doped tin oxide), ZnO, AZO (Al-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO ₂ , FTO (fluorine). Doped tin oxide). The light transmittance of the transparent electrode film is preferably 60% or more, more preferably 80% or more, more preferably, in the photoelectric conversion light absorption peak wavelength of the photoelectric conversion film included in the photoelectric conversion element including the transparent electrode film. It is 90% or more, more preferably 95% or more. The preferred range of the surface resistance of the transparent electrode film varies depending on whether it is a pixel electrode or a counter electrode, and whether the charge storage / transfer / read-out site is a CCD structure or a CMOS structure. When it is used for the counter electrode and the charge storage / transfer / readout part has a CMOS structure, it is preferably 10000Ω / □ or less, more preferably 1000Ω / □ or less. When it is used for the counter electrode and the charge storage / transfer / readout part has a CCD structure, it is preferably 1000Ω / □ or less, more preferably 100Ω / □ or less. When used for a pixel electrode, it is preferably 1000000 Ω / □ or less, more preferably 100000 Ω / □ or less.
The conditions at the time of forming the transparent electrode film will be mentioned. The substrate temperature at the time of forming the transparent electrode film is preferably 500 ° C. or lower, more preferably 300 ° C. or lower, further preferably 200 ° C. or lower, and further preferably 150 ° C. or lower. Further, a gas may be introduced during the formation of the transparent electrode film, and basically the gas species is not limited, but Ar, He, oxygen, nitrogen and the like can be used. Further, a mixed gas of these gases may be used. In particular, in the case of an oxide material, oxygen defects are often introduced, so that oxygen is preferably used.

(Inorganic layer)
The inorganic layer as the electromagnetic wave absorption / photoelectric conversion site will be described. In this case, light passing through the upper organic layer is photoelectrically converted by the inorganic layer. As the inorganic layer, a pn junction or a pin junction of a compound semiconductor such as crystalline silicon, amorphous silicon, or GaAs is generally used. The method disclosed in US Pat. No. 5,965,875 can be adopted as the laminated structure. In other words, a stacked light receiving portion is formed using the wavelength dependency of the absorption coefficient of silicon, and color separation is performed in the depth direction. In this case, since the color separation is performed based on the light penetration depth of silicon, the spectral range detected by each of the stacked light receiving units is broad. However, color separation is remarkably improved by using the above-described organic layer as an upper layer, that is, by detecting light transmitted through the organic layer in the depth direction of silicon. In particular, when the G layer is arranged in the organic layer, the light transmitted through the organic layer becomes B light and R light, so that the separation of light in the depth direction in silicon becomes only BR light, and the color separation is improved. Even when the organic layer is a B layer or an R layer, color separation is remarkably improved by appropriately selecting the electromagnetic wave absorption / photoelectric conversion site of silicon in the depth direction. When the organic layer has two layers, the function as an electromagnetic wave absorption / photoelectric conversion site in silicon may be basically one color, and preferable color separation can be achieved.

The inorganic layer is preferably formed by stacking a plurality of photodiodes for each pixel in the depth direction in the semiconductor substrate, and a color signal corresponding to a signal charge generated in each photodiode by light absorbed by the plurality of photodiodes. It is a structure that reads out to the outside. Preferably, the plurality of photodiodes include a first photodiode provided at a depth that absorbs B light and at least one of a second photodiode provided at a depth that absorbs R light, It is preferable to include a color signal readout circuit that reads out a color signal corresponding to the signal charge generated in each of the plurality of photodiodes. With this configuration, color separation can be performed without using a color filter. In some cases, light of a negative sensitivity component can also be detected, so that color imaging with good color reproducibility is possible. In the present invention, the junction portion of the first photodiode is formed to a depth of about 0.2 μm from the surface of the semiconductor substrate, and the junction portion of the second photodiode is the surface of the semiconductor substrate. To a depth of about 2 μm.
The inorganic layer will be described in more detail. As a preferable configuration of the inorganic layer, a photoconductive type, a pn junction type, a Schottky junction type, a PIN junction type, an MSM (metal-semiconductor-metal) type light receiving element or a phototransistor type light receiving element can be given. In the present invention, a plurality of first conductivity type regions and second conductivity type regions opposite to the first conductivity type are alternately stacked in a single semiconductor substrate, and the first conductivity type is stacked. It is preferable to use a light receiving element in which each joint surface of the mold and the second conductivity type region is formed to a depth suitable for mainly photoelectrically converting light in a plurality of different wavelength bands. As the single semiconductor substrate, single crystal silicon is preferable, and color separation can be performed using absorption wavelength characteristics depending on the depth direction of the silicon substrate.
As the inorganic semiconductor, an InGaN-based, InAlN-based, InAlP-based, or InGaAlP-based inorganic semiconductor can also be used. The InGaN-based inorganic semiconductor is adjusted so as to have a maximum absorption value in a blue wavelength range by appropriately changing the In-containing composition. That is, the composition is In _x Ga _1-x N (0 <X <1). Such a compound semiconductor is manufactured using a metal organic chemical vapor deposition method (MOCVD method). A nitride semiconductor InAlN system using Al, which is the same group 13 source material as Ga, can also be used as a short wavelength light receiving section in the same manner as the InGaN system. InAlP or InGaAlP lattice-matched to the GaAs substrate can also be used.

The inorganic semiconductor may have a buried structure. The embedded structure means a structure in which both ends of the short wavelength light receiving part are covered with a semiconductor different from the short wavelength light receiving part. The semiconductor covering both ends is preferably a semiconductor having a band gap wavelength shorter than or equivalent to the band gap wavelength of the short wavelength light receiving part.
The organic layer and the inorganic layer may be combined in any form. In addition, it is preferable to provide an insulating layer between the organic layer and the inorganic layer in order to electrically insulate.
The junction is preferably npn or pnpn from the light incident side. In particular, by providing a p layer on the surface and increasing the surface potential, holes generated in the vicinity of the surface and dark current can be trapped and dark current can be reduced. preferable.
In such a photodiode, an n-type layer, a p-type layer, an n-type layer, and a p-type layer that are sequentially diffused from the surface of the p-type silicon substrate are formed deeply in this order, so that the pn junction diode has a silicon depth. Four layers of pnpn are formed in the direction. The light incident on the diode from the surface side penetrates deeper as the wavelength is longer, and the incident wavelength and attenuation coefficient show values specific to silicon, so that the depth of the pn junction surface covers each wavelength band of visible light. design. Similarly, an n-type layer, a p-type layer, and an n-type layer are formed in this order to obtain a npn three-layer junction diode. Here, an optical signal is taken out from the n-type layer, and the p-type layer is connected to the ground.
Further, when an extraction electrode is provided in each region and a predetermined reset potential is applied, each region is depleted, and the capacitance of each junction becomes an extremely small value. Thereby, the capacity | capacitance produced in a joint surface can be made very small.

(Auxiliary layer)
In the present invention, an ultraviolet absorption layer and / or an infrared absorption layer are preferably provided on the uppermost layer of the electromagnetic wave absorption / photoelectric conversion site. The ultraviolet absorbing layer can absorb or reflect at least light of 400 nm or less, and preferably has an absorptance of 50% or more in a wavelength region of 400 nm or less. The infrared absorbing layer can absorb or reflect light of at least 700 nm or more, and preferably has an absorptance of 50% or more in a wavelength region of 700 nm or more.
These ultraviolet absorbing layer and infrared absorbing layer can be formed by a conventionally known method. For example, there is a method in which a mordanting layer made of a hydrophilic polymer material such as gelatin, casein, mulled or polyvinyl alcohol is provided on a substrate, and a dye having a desired absorption wavelength is added or dyed to the mordanting layer to form a colored layer. Are known. Furthermore, a method using a colored resin in which a certain kind of coloring material is dispersed in a transparent resin is known. For example, JP-A-58-46325, JP-A-60-78401, JP-A-60-184202, JP-A-60-184203, JP-A-60-184204, JP-A-60-184204 As shown in Japanese Patent Application Laid-Open No. 60-184205 and the like, a colored resin film obtained by mixing a colorant with a polyamino resin can be used. A colorant using a polyimide resin having photosensitivity is also possible.
Dispersing a coloring material in an aromatic polyamide resin having a photosensitivity group described in JP-B-7-113685 in the molecule and capable of obtaining a cured film at 200 ° C. or lower, JP-B-7-69486 It is also possible to use dispersed colored resins with the stated content.
In the present invention, a dielectric multilayer film is preferably used. The dielectric multilayer film is preferably used because the wavelength dependency of light transmission is sharp.
Each electromagnetic wave absorption / photoelectric conversion site is preferably separated by an insulating layer. The insulating layer can be formed using a transparent insulating material such as glass, polyethylene, polyethylene terephthalate, polyethersulfone, and polypropylene. Silicon nitride, silicon oxide and the like are also preferably used. Silicon nitride formed by plasma CVD is preferably used in the present invention because it has high density and good transparency.
A protective layer or a sealing layer can be provided for the purpose of preventing contact with oxygen or moisture. Examples of protective layers include diamond thin films, inorganic material films such as metal oxides and metal nitrides, polymer films such as fluororesins, polyparaxylene, polyethylene, silicon resins, and polystyrene resins, and photocurable resins. Can be mentioned. Further, the element portion can be covered with glass, gas-impermeable plastic, metal, etc., and the element itself can be packaged with an appropriate sealing resin. In this case, a substance having high water absorption can be present in the packaging.
Furthermore, since the light collection efficiency can be improved by forming the microlens array on the light receiving element, such an embodiment is also preferable.

(Charge accumulation / transfer / readout part)
Regarding the charge transfer / readout part, JP-A-58-103166, JP-A-58-103165, JP-A-2003-332551 and the like can be referred to. A structure in which a MOS transistor is formed on a semiconductor substrate for each pixel unit or a structure having a CCD as an element can be appropriately employed. For example, in the case of a photoelectric conversion element using a MOS transistor, charges are generated in the photoconductive film by incident light transmitted through the electrodes, and the charges are generated by an electric field generated between the electrodes by applying a voltage to the electrodes. It travels to the electrode through the photoconductive film, and further moves to the charge storage part of the MOS transistor, and charges are stored in the charge storage part. The charge accumulated in the charge accumulation unit moves to the charge readout unit by switching of the MOS transistor, and is further output as an electric signal. Thereby, a full-color image signal is input to the solid-state imaging device including the signal processing unit.
It is possible to inject a certain amount of bias charge into the storage diode (refresh mode) and store the constant charge (photoelectric conversion mode), and then read out the signal charge. The light receiving element itself can be used as a storage diode, or a storage diode can be additionally provided.

The signal readout will be described in more detail. An ordinary color readout circuit can be used for signal readout. The signal charge or signal current optically / electrically converted by the light receiving unit is stored in the light receiving unit itself or an attached capacitor. The stored charge is read out together with the selection of the pixel position by a technique of a MOS type image pickup device (so-called CMOS sensor) using an XY address method. In addition, as an address selection method, there is a method in which each pixel is sequentially selected by a multiplexer switch and a digital shift register and read as a signal voltage (or charge) to a common output line. An image sensor for XY address operation arranged in a two-dimensional array is known as a CMOS sensor. This is because when a switch connected to a pixel connected to the intersection of XY is connected to a vertical shift register, and the switch is turned on by a voltage from the vertical scanning shift register, it is read out from the pixel placed in the same row. The read signal is read out to the output line in the column direction. This signal is read from the output end in turn through a switch driven by a horizontal scanning shift register.
For reading out the output signal, a floating diffusion detector or a floating gate detector can be used. Further, the S / N can be improved by providing a signal amplification circuit in the pixel portion or a correlated double sampling technique.

For signal processing, gamma correction by an ADC circuit, digitization by an AD converter, luminance signal processing, and color signal signal processing can be performed. Examples of the color signal processing include white balance processing, color separation processing, and color matrix processing. When used for NTSC signals, RGB signals can be converted to YIQ signals.
The charge transfer / readout portion needs to have a charge mobility of 100 cm ² / volt · sec or more, and this mobility is selected from a group IV, III-V, or II-VI group semiconductor. Can be obtained. Of these, silicon semiconductors (also referred to as Si semiconductors) are preferable because miniaturization technology is advanced and the cost is low. Many methods of charge transfer and charge reading have been proposed, but any method may be used. A particularly preferred method is a CMOS type or CCD type device. Furthermore, in the case of the present invention, the CMOS type is often preferable in terms of high-speed readout, pixel addition, partial readout, power consumption, and the like.

(Connection)
A plurality of contact parts for connecting the electromagnetic wave absorption / photoelectric conversion part and the charge transfer / reading part may be connected by any metal, but preferably selected from copper, aluminum, silver, gold, chromium, and tungsten. In particular, copper is preferred. In accordance with a plurality of electromagnetic wave absorption / photoelectric conversion parts, it is necessary to install each contact part between the charge transfer / readout part. When a laminated structure of a plurality of photosensitive units of blue, green, and red light is adopted, between the blue light extraction electrode and the charge transfer / readout portion, between the green light extraction electrode and the charge transfer / readout portion, and the red light extraction electrode; It is necessary to connect between the charge transfer / readout portions.

(process)
The laminated photoelectric conversion device of the present invention can be manufactured according to a so-called microfabrication process used for manufacturing a known integrated circuit or the like. Basically, this method uses pattern exposure by active light or electron beam (mercury i, g emission line, excimer laser, X-ray, electron beam), pattern formation by development and / or burning, and element formation material. By repeated operations of placement (coating, vapor deposition, sputtering, CV, etc.) and removal of non-patterned material (heat treatment, dissolution treatment, etc.).

(Use)
The chip size of the device can be selected from brownie size, 135 size, APS size, 1 / 1.8 inch, and even smaller size. The pixel size of the laminated photoelectric conversion element of the present invention is represented by a circle-equivalent diameter corresponding to the maximum area of a plurality of electromagnetic wave absorption / photoelectric conversion sites. Any pixel size may be used, but a pixel size of 2 to 20 microns is preferable. More preferably, it is 2-10 microns, but 3-8 microns is particularly preferable.
When the pixel size exceeds 20 microns, the resolving power decreases, and even if the pixel size is smaller than 2 microns, the resolving power decreases due to radio wave interference between the sizes.
The photoelectric conversion element of the present invention can be used for a digital still camera. It is also preferable to use it for a TV camera. Other applications include digital video cameras, surveillance cameras for the following applications (office buildings, parking lots, financial institutions and unmanned contractors, shopping centers, convenience stores, outlet malls, department stores, pachinko halls, karaoke boxes, game centers, Hospital), various other sensors (TV door phone, personal authentication sensor, factory automation sensor, home robot, industrial robot, piping inspection system), medical sensor (endoscope, fundus camera), video conference system, It can be used for applications such as videophones, mobile phones with cameras, safe driving systems for vehicles (back guide monitors, collision prediction, lane keeping systems), and video game sensors.

Especially, the photoelectric conversion element of this invention is suitable also for a television camera use. This is because a television camera can be reduced in size and weight because no color separation optical system is required. Moreover, since it has high sensitivity and high resolution, it is particularly preferable for a television camera for high-definition broadcasting. In this case, the high-definition broadcast television camera includes a digital high-definition broadcast camera.
Furthermore, the photoelectric conversion element of the present invention is preferable in that an optical low-pass filter can be eliminated and further high sensitivity and high resolution can be expected.
Furthermore, in the photoelectric conversion element of the present invention, it is possible to reduce the thickness and eliminate the need for a color separation optical system, so that "an environment with different brightness such as daytime and nighttime" For shooting scenes that require different sensitivities, such as `` subjects that are moving '' and `` moving subjects, '' and other scenes that require different spectral sensitivity and color reproducibility, replace the photoelectric conversion element of the present invention and shoot. A single camera can meet a variety of shooting needs, and it is not necessary to carry multiple cameras at the same time, reducing the burden on the photographer. As a photoelectric conversion element to be exchanged, an exchange photoelectric conversion element can be prepared for the purpose of infrared light photography, black-and-white photography, and dynamic range change in addition to the above.
The TV camera of the present invention can be obtained by referring to the description in Chapter 2 of the Institute of Image Information Media, Television Camera Design Technology (August 20, 1999, issued by Corona, ISBN 4-339-00714-5). Fig. 2.1 The television camera can be manufactured by replacing the color separation optical system and the imaging device in the basic configuration with the photoelectric conversion element of the present invention.
The above-described stacked light receiving elements can be used not only as an image pickup element by arranging them but also as a light sensor such as a biosensor or a chemical sensor or a color light receiving element as a single unit.

(Preferred photoelectric conversion element of the present invention)
A preferred photoelectric conversion element of the present invention will be described with reference to FIG. Reference numeral 13 denotes a silicon single crystal substrate, which serves as an electromagnetic wave absorption / photoelectric conversion site for B light and R light and a charge accumulation / transfer / readout site for charges generated by photoelectric conversion. Usually, a p-type silicon substrate is used. Reference numerals 21, 22, and 23 denote an n layer, a p layer, and an n layer provided in the silicon substrate, respectively. The n layer 21 is an R light signal charge accumulating unit for accumulating the R light signal charge photoelectrically converted by the pn junction. The accumulated charges are connected to 27 signal readout pads through 19 transistors through 19 transistors. The n layer 23 is a B light signal charge accumulating unit for accumulating B light signal charges photoelectrically converted by a pn junction. The accumulated electric charge is connected to 27 signal readout pads through 19 metal wires through transistors similar to 26. Here, the p layer, the n layer, the transistor, the metal wiring, and the like are schematically shown. However, as described in detail in the previous discussion, an optimal structure is appropriately selected. Since B light and R light are separated according to the depth of the silicon substrate, selection of the depth from the silicon substrate such as a pn junction and the doping concentration is important. Reference numeral 12 denotes a layer containing metal wiring, which is mainly composed of silicon oxide, silicon nitride, or the like. The thickness of the layer 12 is preferably as small as possible, and is 5 μm or less, preferably 3 μm or less, more preferably 2 μm or less. Similarly, 11 is a layer mainly composed of silicon oxide, silicon nitride or the like. The layers 11 and 12 are provided with plugs for sending the signal charges of G light to the silicon substrate. The plug is connected by 16 pads between the 11 and 12 layers. The plug is preferably made mainly of tungsten. A pad mainly composed of aluminum is preferably used. It is preferable that a barrier layer is provided including the metal wiring described above. The signal charges of G light transmitted through the 15 plugs are accumulated in the n layer indicated by 25 in the silicon substrate. The n layer shown in 25 is separated by the p layer shown in 24. The accumulated electric charge is connected to 27 signal readout pads through 19 metal wires through transistors similar to 26. Since photoelectric conversion by the pn junctions 24 and 25 causes noise, the light shielding film shown in 17 is provided in 11 layers. As the light shielding film, a film mainly composed of tungsten, aluminum or the like is usually used. The thickness of the layer 12 is preferably as small as possible, and is 3 μm or less, preferably 2 μm or less, more preferably 1 μm or less. 27 signal readout pads are preferably provided for each of the B, G, and R signals. The above process can be prepared by a conventionally known process, a so-called CMOS process.

  The electromagnetic wave absorption / photoelectric conversion site of G light is indicated by 6, 7, 8, 9, 10, and 14. Reference numerals 6 and 14 denote transparent electrodes, which correspond to a counter electrode and a pixel electrode, respectively. The pixel electrode 14 is a transparent electrode, but in many cases, a portion such as aluminum or molybdenum is required for the connection portion in order to improve electrical connection with the 15 plugs. A bias is applied between these transparent electrodes through wiring from 18 connection electrodes and 20 counter electrode pads. A structure in which electrons can be stored in 25 by applying a positive bias to the pixel electrode 14 with respect to the transparent counter electrode 6 is preferable. In this case, 7 is an electron blocking layer, 8 is a p layer, 9 is an n layer, and 10 is a hole blocking layer, showing a typical organic layer structure. The thickness of the organic layer composed of 7, 8, 9, 10 is preferably 0.5 μm or less, more preferably 0.3 μm or less, and particularly preferably 0.2 μm or less. The thicknesses of the transparent counter electrode 6 and the transparent pixel electrode 14 are particularly preferably 0.2 μm or less. Reference numerals 3, 4, and 5 are protective films mainly composed of silicon nitride or the like. These protective films facilitate the manufacturing process of the layer including the organic layer. In particular, these layers can reduce damage to the organic layer during the formation of a resist pattern at the time of forming connection electrodes such as 18 and during etching. Further, in order to avoid the formation of a resist pattern, etching, etc., it is possible to manufacture with a mask. The thicknesses of the protective films 3, 4, and 5 are preferably 0.5 μm or less as long as the above-described conditions are satisfied. 3 is a protective film of 18 connection electrodes. Reference numeral 2 denotes an infrared cut dielectric multilayer film. Reference numeral 1 denotes an antireflection film. The total thickness of the layers 1, 2, and 3 is preferably 1 μm or less.

  The photoelectric conversion element described with reference to FIG. 1 has a configuration in which the G pixel is 4 pixels and the B pixel and the R pixel are 1 pixel. The G pixel may be configured with one B pixel and the R pixel for one pixel, or the G pixel may be configured with one pixel for the B pixel and the R pixel for three pixels. In addition, the B pixel and the R pixel may be configured as one pixel with respect to the G pixel as two pixels. Furthermore, arbitrary combinations may be used. Although the above shows the preferable aspect of this invention, it is not limited to this.

[Example]
Examples and embodiment examples of the present invention will be described below, but the present invention is not limited thereto.

  1,3-diphenyl-5-[(3- (2-phenoxyethyl) -2 (3H) -5-phenylbenzoxazolylidene) is deposited on an indium tin oxide (ITO) thin film using a vacuum deposition method. Ethylden] ethylidene] -2,4,6 (1H, 3H, 5H) -pyrimidinetrione (dimethine merocyanine: compound 1) with a thickness of 50 nm was formed, and then perylene-3,4,9,10 -A 50 nm thick layer of tetracarboxyl-bis-benzimidazole (compound 2) is formed. Furthermore, a semi-transparent aluminum electrode having a film thickness of 40 nm can be formed to obtain the photoconductive film A. A photoconductive film B that is the same as the photoconductive film A except that the compound 3 is used instead of the compound 1 in the photoconductive film A is used for comparison.

From the analysis of the electron diffraction image of the photoconductive film A, it can be seen that the orientation of (Compound 1) is as shown in the conceptual diagram (FIG. 2). (Compound 1) has a high self-association property and forms such a stable structure. Such strong self-association is considered to be mainly caused by the van der Waals force of (Compound 1).
In addition, the image pick-up element which divided these photoconductive films A and B into pixels is set as image pick-up elements A and B, respectively.

The optical response current of the image sensor A is 1.5 times that of the image sensor B. Further, by applying a forward voltage of 5v between the electrodes (a positive voltage is applied to the aluminum electrode) (that is, an electric field of 5 × 10 ⁷ V / m), the photoresponsive current of the image sensor A does not apply a voltage. In contrast to the case of 2.5 times, the photoresponse current of the comparative image sensor B is only twice that of the case where no voltage is applied. The same result can be obtained even if the stacking order of (Compound 1) and (Compound 2) is reversed. In this case, the polarity of voltage application is reversed. Similar results can be obtained by using a translucent gold electrode having a thickness of 20 nm instead of the aluminum electrode.
As described above, an image sensor having an organic layer with a controlled orientation has a higher photoresponse current and higher sensitivity as an image sensor than an image sensor without these structures, and when a voltage is applied. The sensitivity becomes remarkably high.

1,3-diphenyl-5-[(3- (2-phenoxyethyl) -2 (3H) -5-phenylbenzoxazolylidene) is deposited on an indium tin oxide (ITO) thin film using a vacuum deposition method. A 10 nm thick layer of ethylden] ethylidene] -2,4,6 (1H, 3H, 5H) -pyrimidinetrione (dimethine merocyanine: compound 1) was formed, and then (compound 1) and 1,3- Dicyanoethyl-5-[(3-benzyl-2 (3H) -5-naphtho [2,3-d] oxazolidylidene) ethylden] ethylidene] -2,4,6 (1H, 3H, 5H) -pyrimidinetrione (Dimethy Nmerocyanine: compound 4) is co-evaporated at a ratio of 1: 1 to form a layer having a thickness of 80 nm, and then a 10 nm-thick layer of (compound 4) is formed by vapor deposition. Furthermore, a 40 nm thick translucent aluminum electrode can be formed to obtain the photoconductive film C. Note that the photoconductive film B described in Example 1 is used for comparison.
From the analysis of the electron diffraction image of the photoconductive film C, it can be seen that the orientation of the compound is as shown in the conceptual diagram (FIG. 3). Both (Compound 1) and (Compound 4) have high self-association properties, and such a stable structure is formed. We believe that such strong self-association is mainly due to the van der Waals forces of these compounds.
In addition, the image pick-up element which divided these photoconductive films C and B into a pixel is set as image pick-up element C and B, respectively.
The optical response current of the image sensor C is three times that of the image sensor B. Furthermore, by applying a voltage of 5v between the electrodes (a positive voltage is applied to the aluminum electrode) (that is, an electric field of 5 × 10 ⁷ V / m), the optical response current of the image sensor A is compared with the case where no voltage is applied. In contrast, the photoresponse current of the comparative image sensor B is only twice that of the case where no voltage is applied. The same result can be obtained even if the stacking order of (Compound 1) and (Compound 4) is reversed. In this case, the polarity of voltage application is reversed. Similar results can be obtained by using a translucent gold electrode having a thickness of 20 nm instead of the aluminum electrode.
As described above, an image sensor having an organic layer with a controlled orientation has a higher photoresponse current and higher sensitivity as an image sensor than an image sensor without these structures, and when a voltage is applied. The sensitivity becomes remarkably high.

The same elements as in Example 2 show superior performance as compared with Example 2 except that the compounds used in the image sensor described in Example 2 were changed as follows.
(Compound 1) is changed to tetramethine merocyanine (compound 5) obtained by extending the methine chain of (compound 1) to four (compound 4) is changed to tetramethine merocyanine (compound (4)). Change to 6)

The same elements as in Example 2 show superior performance as compared with Example 2 except that the compounds used in the image sensor described in Example 2 were changed as follows.
(Compound 1) is changed to zero methine merocyanine (compound 7) from which the methine chain of (Compound 1) is removed (Compound 4) is changed to zero methine merocyanine (Compound 8) from which the methine chain of (Compound 4) is removed

  The image pickup device of Example 4 is a B layer, the image pickup device of Example 2 is a G layer, and the image pickup device of Example 3 is an R layer. It shows current and has high sensitivity, and is excellent as a color imaging device.

The present invention and prior art in Examples 1 to 5 will be described with reference to a conceptual diagram (see FIG. 2).
In the prior art (Japanese Patent Application Laid-Open No. 2003-158254, etc.), a pn junction whose orientation is not controlled is used, but the present application controls the orientation of at least one organic compound (pigment) as shown in FIG.
Moreover, the conceptual diagram regarding the heterojunction surface of this invention is shown in FIG. Furthermore, it is preferable that the heterojunction plane as shown in the figure is perpendicular to the substrate.
Non-patent document 1 and Japanese Patent Application Laid-Open No. 2003-298152, which are prior arts, are suitable only for photoelectric conversion elements intended for energy utilization, and Patent Documents 1 to 3 refer to the orientation of organic compounds. The difference is that the imaging device includes a controlled structure.

On the indium tin oxide (ITO) thin film, a layer having a thickness of 50 nm of (Dye 9) is formed by spin coating, and then a layer having a thickness of 50 nm of (Material 1) is formed by vacuum evaporation. Furthermore, a translucent gold electrode having a film thickness of 20 nm can be formed by a vacuum deposition method, and the photoelectric conversion element A can be obtained. Further, the same photoelectric conversion element B is used except that (dye 10) is used instead of (dye 9) of photoelectric conversion element A. In addition, let the image pick-up element which divided these photoelectric conversion elements A and B into a pixel be image pick-up elements A and B, respectively.
The absorption maximum wavelength of the photoelectric conversion film of the photoelectric conversion element A is 640 nm, and the long wave absorption width is 23 nm. The absorption maximum wavelength of (Dye 9) in the DMF solution is 553 nm, and the long wave absorption width is 17 nm. On the other hand, the absorption maximum wavelength of the photoelectric conversion film of the photoelectric conversion element B is 555 nm, and the long wave absorption width is 43 nm. In addition, the absorption maximum wavelength in the DMF solution of (Dye 10) is 562 nm.
The optical response current of the image sensor A is twice that of the image sensor B.
Further, by applying a reverse bias of a voltage of 5v between the electrodes (a positive voltage is applied to the gold electrode), that is, by applying an electric field of 5 × 10 ⁷ V / m, no voltage is applied to the photoresponse current of the image sensor A. Compared to the case, the photoresponse current of the comparative image pickup element B is only twice that in the case where no voltage is applied.
Further, the optical response current after the image sensor A is aged for 3 days at a temperature = 80 ° C. and a humidity = 50% is equivalent to that of the fresh element A, whereas the image sensor B is subjected to the same conditions under the same conditions. The photoresponse current after the reduction was 10% lower than that of the fresh element B.
The same result can be obtained even if the stacking order of (Dye 9, 10) and (Material 1) is reversed. In this case, the polarity of voltage application is reversed.
As described above, the imaging element A composed of a photoelectric conversion film in which a dye forms a J aggregate in a film state is more photoresponsive than the imaging element B composed of a photoelectric conversion film that does not form a J aggregate in a film state. Is high and has high sensitivity as an image pickup device, and becomes significantly sensitive when a voltage is applied. Furthermore, there is little decrease in sensitivity due to storage.

A similar element of the present invention, except that the compound used in the imaging element described in Example 6 is changed as follows, exhibits excellent performance as compared to Example 6 with respect to the comparative element.
Element of the present invention (photoelectric conversion element C, imaging element C): (Dye 9) is changed to (Dye 11) Comparison element (Photoelectric conversion element D, imaging element D): (Dye 10) is changed to (Dye 12) The absorption maximum wavelength of the photoelectric conversion film of the photoelectric conversion element C is 545 nm, and the long wave absorption width is 20 nm. The absorption maximum wavelength of (Dye 11) in the DMF solution is 502 nm, and the long wave absorption width is 15 nm. On the other hand, the absorption maximum wavelength of the photoelectric conversion film of the photoelectric conversion element D is 483 nm, and the long wave absorption width is 42 nm. In addition, the absorption maximum wavelength in the DMF solution of (Dye 12) is 485 nm.

A similar element of the present invention, except that the compound used in the imaging element described in Example 6 is changed as follows, exhibits excellent performance as compared to Example 6 with respect to the comparative element.
Element (photoelectric conversion element E, imaging element E) of the present invention: (Dye 9) changed to (Dye 13) Comparison element (photoelectric conversion element F, imaging element F): (Dye 10) changed to (Dye 14) The absorption maximum wavelength of the photoelectric conversion film of the photoelectric conversion element E is 480 nm, and the long wave absorption width is 19 nm. The absorption maximum wavelength of (Dye 13) in the DMF solution is 442 nm, and the long wave absorption width is 15 nm. On the other hand, the absorption maximum wavelength of the photoelectric conversion film of the photoelectric conversion element F is 423 nm, and the long wave absorption width is 41 nm. In addition, the absorption maximum wavelength in the DMF solution of (Dye 14) is 425 nm.

  The imaging device of Example 8 is a B layer (B film), the imaging device of Example 7 is a G layer (G film), and the imaging device of Example 6 is an R layer (R film). In each of the image pickup devices shown in (1), each layer exhibits an excellent photoresponse current for comparison, is highly sensitive, and has excellent color reproducibility as a color image pickup device. Furthermore, it is excellent in durability.

On the indium tin oxide (ITO) thin film, a layer having a thickness of 50 nm (dye 15) is formed by spin coating, and then a layer having a thickness of 50 nm (material 2) is formed by vacuum deposition. Furthermore, a translucent gold electrode having a film thickness of 20 nm can be formed by a vacuum deposition method, and the photoelectric conversion element A can be obtained. The same photoconductive element B is used except that (dye 16) is used instead of (dye 15) of photoelectric conversion element A. In addition, the image pick-up element which divided these photoconductive elements A and B into a pixel is set as image pick-up element A and B, respectively.
The transition dipole moment of (Dye 15) and (Dye 16) is determined by the method described in the text, and the angle formed by the spectral absorption transition dipole moment of (Dye 15) and the electrode plane of the photoelectric conversion element is 1 °. It is 43 ° for (Dye 16).
The light absorption rate of the photoelectric conversion film of the photoelectric conversion element A is 1.2 times the light absorption rate of the photoelectric conversion film of the photoelectric conversion element B.
In addition, the optical response current of the image sensor A is 2.2 times that of the image sensor B.
Further, by applying a reverse bias of a voltage of 5v between the electrodes (a positive voltage is applied to the gold electrode), that is, by applying an electric field of 5 × 10 ⁷ V / m, the photoresponse current of the image sensor A does not apply a voltage. In contrast to the case of 2.8, the photoresponse current of the comparative image sensor B is only twice that of the case where no voltage is applied.
The same result can be obtained even if the stacking order of (Dye 15, 16) and (Material 2) is reversed. In this case, the polarity of voltage application is reversed.
As described above, in an imaging device including a photoelectric conversion film having an angle between the spectral absorption transition dipole moment of the dye and the electrode plane of the photoelectric conversion element in the film state of 40 ° or less, the photoelectric conversion having this angle of 40 ° or more is performed. Compared to an imaging device made of a film, the light absorption rate is high, the photoresponse current is high, and the imaging device is highly sensitive. When a voltage is applied, the sensitivity becomes significantly high.

The same element of the present invention except that the compound used in the imaging element described in Example 10 was changed as follows shows excellent performance as compared to Example 10 with respect to the comparative element.
Element (photoelectric conversion element C, imaging element C) of the present invention: (Dye 15) changed to (Dye 17) Comparison element (photoelectric conversion element D, imaging element D): (Dye 16) changed to (Dye 18) The angle formed by the spectral absorption transition dipole moment of (Dye 17) and the electrode plane of the photoelectric conversion element is 0.5 °, and (Dye 18) is 44 °.

The same element of the present invention except that the compound used in the imaging element described in Example 10 was changed as follows shows excellent performance as compared to Example 10 with respect to the comparative element.
Element of the present invention (photoelectric conversion element E, imaging element E): (Dye 15) is changed to (Dye 19) Comparison element (Photoelectric conversion element F, imaging element F): (Dye 16) is changed to (Dye 20) The angle formed between the spectral absorption transition dipole moment of (Dye 19) and the electrode plane of the photoelectric conversion element is 2 °, and (Dye 20) is 43 °.

  The imaging device shown in FIG. 1 is formed by stacking three layers, with the imaging device of Example 12 being a B layer (B film), the 11 imaging device being a G layer (G film), and the 10 imaging device being an R layer (R film). In each of the layers, the light absorption rate is higher than the comparison, and an excellent photoresponse current is shown and high sensitivity.

  When the photoelectric conversion site that absorbs the G light of Example 2, Example 7, or Example 11 is used in the parts 8 and 9 of the photoelectric conversion site in FIG. High sensitivity and excellent color separation as a color image sensor.

It is a cross-sectional schematic diagram for 1 pixel of the photoelectric conversion film laminated | stacked image pick-up element of BGR 3 layer lamination by this invention. It is a cross-sectional schematic diagram which shows the orientation control by this invention. It is a cross-sectional schematic diagram which shows the orientation control in the case of having a bulk heterojunction surface by this invention. It is the photoelectric conversion element of the preferable aspect of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antireflection film 2 Infrared cut dielectric multilayer film 3, 4, 5 Protective film 6 Transparent counter electrode 7 Electron blocking layer 8 P layer 9 N layer 10 Hole blocking layer 11, 12 Layer including metal wiring 13 Silicon single crystal Base 14 Transparent pixel electrode 15 Plug 16 Pad 17 Light shielding film 18 Connection electrode 19 Metal wiring 20 Counter electrode pad 21 n layer 22 p layer 23 n layer 24 p layer 25 n layer 26 Transistor 27 Signal readout pad 101 P well layers 102, 104 , 106 High-concentration impurity regions 103, 105, 107 MOS circuit 108 Gate insulating film 109, 110 Insulating film 111, 114, 116, 119, 121, 124, transparent electrode film 112, 117, 122, electrode 113, 118, 123 photoelectric Conversion film 110, 115, 120, 125 Transparent insulating film 126 Light shielding film 150 Semiconductor Substrate

Claims (33)

  A photoelectric conversion film having at least one organic dye compound, wherein the organic dye compound forms a J aggregate.   A photoelectric conversion film having at least one organic dye compound, wherein the angle formed by the spectral absorption transition dipole moment of the organic dye compound and the plane of the photoelectric conversion film is 40 ° or less.   A photoelectric conversion element comprising the photoelectric conversion film according to claim 1 and a pair of electrodes sandwiching the photoelectric conversion film.   An image pickup device comprising the photoelectric conversion device according to claim 3.   In an imaging device having a photoelectric conversion film in which a p-type semiconductor layer and an n-type semiconductor layer have a stacked structure between a pair of electrodes, the orientation-controlled organic in at least one of the p-type semiconductor and the n-type semiconductor An imaging device comprising a compound.   In an imaging device having a photoelectric conversion film having a mixed / dispersed (bulk heterojunction structure) layer of a p-type semiconductor and an n-type semiconductor between a pair of electrodes, oriented in at least one of a p-type semiconductor and an n-type semiconductor An imaging device comprising a controlled organic compound.   In an imaging element having a p-type semiconductor layer, an n-type semiconductor layer between a pair of electrodes, and a photoelectric conversion film having a bulk heterojunction structure layer layer therebetween, at least one of a p-type semiconductor and an n-type semiconductor The imaging device according to claim 6, further comprising an organic compound whose orientation is controlled.   The image pickup device according to claim 5, comprising an organic compound whose orientation is controlled in both the p-type semiconductor and the n-type semiconductor.   The image sensor according to claim 5, wherein the orientation-controlled organic compound is an organic dye.   The image pickup device according to claim 9, wherein the organic dye is a merocyanine dye.   The photoelectric conversion film according to claim 1, the photoelectric conversion element according to claim 3, or any one of claims 4 to 10, wherein the organic compound layer has a thickness of 30 nm to 300 nm. The imaging device described in 1.   An image pickup device comprising two or more layers of the photoelectric conversion film according to claim 1.   The image sensor according to claim 12, wherein the two or more photoelectric conversion elements according to claim 12 include three layers of a blue photoelectric conversion element, a green photoelectric conversion element, and a red photoelectric conversion element.   The photoelectric conversion film according to any one of claims 4 to 13, and the photoelectric conversion according to claim 3, wherein the p-type semiconductor or the n-type semiconductor on the incident light side is colorless. An image sensor according to any one of claims 4 to 13.   When the spectral absorption maximum values are λmax1, λmax2, and λmax3 in the order of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13, λmax1 is 400 nm to 500 nm and λmax2 is 500 nm to 600 nm. 14. The imaging device according to claim 13, wherein λmax3 is in the range of 600 nm to 700 nm.   When the spectral sensitivity maximum values are Smax1, Smax2, and Smax3 in the order of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13, Smax1 is 400 nm to 500 nm and Smax2 is 500 nm to 600 nm. 14. The image sensor according to claim 13, wherein Smax3 is in the range of 600 nm to 700 nm.   The distance between the shortest wavelength and the longest wavelength that indicates 50% of the spectral maximum absorption of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13 is 120 nm or less, respectively. The imaging device according to claim 13.   The distance between the shortest wavelength and the longest wavelength, which indicates 50% of the spectral maximum sensitivity of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13, is 120 nm or less, respectively. The imaging device according to claim 13.   The distance between the shortest wavelength and the longest wavelength, which indicates 80% of the spectral maximum absorption of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13, is 20 nm or more and 100 nm or less, respectively. The image pickup device according to claim 13.   The distance between the shortest wavelength and the longest wavelength, which indicates 80% of the spectral maximum sensitivity of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13, is 20 nm or more and 100 nm or less, respectively. The image pickup device according to claim 13.   The distance between the shortest wavelength and the longest wavelength, which represents 20% of the spectral maximum absorption of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13, is 180 nm or less, respectively. The imaging device according to claim 13.   The distance between the shortest wavelength and the longest wavelength indicating 20% of the spectral maximum sensitivity of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13 is 180 nm or less, respectively. The imaging device according to claim 13.   The longest wavelengths indicating 50% of the spectral maximum absorption in the order of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13 are 460 nm to 510 nm, 560 nm to 610 nm, and 640 nm to 730 nm, respectively. The image pickup device according to claim 13, wherein the image pickup device is provided.   The longest wavelength indicating 50% of the spectral maximum sensitivity in the order of the blue photoelectric conversion element, the green photoelectric conversion element, and the red photoelectric conversion element according to claim 13 is 460 nm to 510 nm, 560 nm to 610 nm, and 640 nm to 730 nm, respectively. The image pickup device according to claim 13, wherein the image pickup device is provided. Claim 1 Mashiku photoelectric conversion film according to 2, the photoelectric conversion element according to claim 3 or 1 × 10 ¹² V / m or more 10V / m in the imaging device according to any one of claims 4 to 24, A method of applying the following electric field, and an applied film or device.   26. An element having at least two electromagnetic wave absorption / photoelectric conversion parts, wherein at least one of these parts comprises the imaging device according to any one of claims 4 to 25.   27. The device according to claim 26, wherein at least two electromagnetic wave absorption / photoelectric conversion sites have a laminated structure of at least two layers.   28. The device according to claim 27, wherein the upper layer comprises a portion capable of absorbing green light and performing photoelectric conversion.   It has at least three electromagnetic wave absorption / photoelectric conversion parts, and at least one of these parts consists of the imaging device according to any one of claims 1 to 20. The described element.   30. The device according to claim 29, wherein the upper layer comprises a portion capable of absorbing green light and performing photoelectric conversion.   The element according to claim 29 or 30, wherein at least two electromagnetic wave absorption / photoelectric conversion sites are made of an inorganic layer.   The element according to claim 29 or 30, wherein at least two electromagnetic wave absorption / photoelectric conversion sites are formed in a silicon substrate. A method for applying an electric field of 10 V / m or more and 1 × 10 ¹² V / m or less to the imaging device according to any one of claims 26 to 32, and an applied device.