JP2009054605A - Photoelectric conversion element, and imaging element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoconductive film and a photoelectric conversion element, having a high photoelectric conversion efficiency and a high S/N ratio. <P>SOLUTION: The photoelectric conversion element is characterized by a structure formed by sequentially laminating two layers of a crystalline organic photoelectric conversion film, and an amorphous film of a different composition from the photoelectric conversion film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion element and an imaging 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 imaging apparatus, it is not necessary to provide a spectral prism, and a single-plate structure with a single 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 in Japanese Patent Application Laid-Open No. 2003-234460 as having a single plate structure with a single 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. .
Japanese Patent Laid-Open No. 2003-332551 describes a multilayer photoconductive film similar to that of Japanese Patent Laid-Open No. 2003-234460.

In JP-A-6-232435, in order to reduce pinholes and electrical shorts of an organic photoelectric conversion element and improve conversion efficiency and reliability, an organic photoelectric conversion layer is formed of an oriented (crystalline) film having the same composition. It is described as being formed from a stack of amorphous films. However, when the alignment film and the amorphous film having the same composition are stacked, the substrate temperature and the deposition conditions must be set separately. For example, in order to make a general crystalline film amorphous, it is necessary to set the substrate during vapor deposition to a low temperature (minus several tens of degrees Celsius). Therefore, the manufacturing process becomes complicated, which is not preferable.
JP 2003-158254 A JP 2003-234460 A JP 2003-332551 A JP-A-6-232435

  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) having high photoelectric conversion efficiency and S / N ratio.

The present invention has been solved by the following means.
(1) A photoelectric conversion element having a structure in which two layers of a crystalline organic photoelectric conversion film and an amorphous film having a composition different from that of the photoelectric conversion film are continuously laminated.
(2) The photoelectric conversion element according to (1), wherein the organic photoelectric conversion film is made of a crystalline merocyanine dye.
(3) The photoelectric conversion element according to (1) or (2), wherein the merocyanine dye is a compound represented by the following general formula (M-1).
General formula (M-1)

In the formula, Z ₁ represents an atomic group forming a 5-membered or 6-membered nitrogen-containing heterocycle. Za represents an atomic group forming a 5-membered or 6-membered ring. R ₁ represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group. L _{11 to} L ₁₄ represent a methine group, may have a substituent, and may form a ring with another methine group. p1 represents 0 or 1. n1 represents an integer of 0 to 4, and when n1 is 2 or more, the plurality of L ₁₃ and L ₁₄ may be the same or different. M1 represents an ion for neutralizing the electric charge, and m1 represents a number necessary for neutralizing the electric charge.
(4) The photoelectric conversion element according to any one of (1) to (3), wherein the amorphous film is made of an organic compound.
(5) The photoelectric conversion element according to any one of (1) to (4), wherein the amorphous film contains at least one compound represented by the following general formula (1).

In formula (1), R _{1 to} R ₁₀ each independently represent a hydrogen atom or a substituent, L represents a monovalent group or a divalent or higher linking group, m represents 0 or 1, and n represents 1 Represents an integer of ~ 4.
(6) The photoelectric conversion element according to any one of (1) to (5), wherein the thickness of the amorphous film / the thickness of the organic photoelectric conversion film is 1 or less.
(7) The photoelectric conversion element according to (6), wherein the organic photoelectric conversion film and the amorphous film are formed by a vacuum deposition method.
(8) An imaging device using the photoelectric conversion device according to any one of (1) to (7).

  According to the present invention, the laminated structure of the crystalline organic photoelectric conversion film and the amorphous film having different compositions can be sequentially stacked without changing the substrate temperature and the deposition conditions. Therefore, the manufacturing process becomes easier than a known method. In addition, this laminated structure has an effect of reducing dark current that is equal to or higher than that of a known method, and the S / N ratio of the organic photoelectric conversion element can be greatly improved.

The present invention is described in detail below. The present invention is characterized by using a photoelectric conversion element having a structure in which a crystalline organic photoelectric conversion film and an amorphous film having a composition different from that of the photoelectric conversion film are continuously laminated.
The crystalline organic photoelectric conversion film is made of a crystalline organic compound and is not particularly limited as long as it is a crystalline organic compound, but is preferably made of a crystalline organic dye compound, more preferably a crystalline merocyanine dye.
The organic photoelectric conversion film is preferably made of a crystalline merocyanine dye. In the merocyanine dye, a dye compound represented by the following general formula (M-1) is preferably used.

  General formula (M-1)

In the formula, Z ₁ represents an atomic group forming a 5-membered or 6-membered nitrogen-containing heterocycle. Za represents an atomic group forming a 5-membered or 6-membered ring. R ₁ represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group. L _{11 to} L ₁₄ represent a methine group, may have a substituent, and may form a ring with another methine group. p1 represents 0 or 1. n1 represents an integer of 0 to 4, and when n1 is 2 or more, the plurality of L ₁₃ and L ₁₄ may be the same or different. M1 represents an ion for neutralizing the electric charge, and m1 represents a number necessary for neutralizing the electric charge.

In formula (M-1), Z ₁ represents an atomic group forming a 5-membered or 6-membered nitrogen-containing heterocycle. The 5-membered or 6-membered nitrogen-containing heterocycle formed is preferably an oxazole nucleus having 3 to 25 carbon atoms (hereinafter referred to as C number) (for example, 2-3-ethyloxazolyl, 2-3-sulfopropyloxa Zolyl, 2-3-sulfopropylbenzoxazolyl, 2-3-ethylbenzoxazolyl, 2-3-sulfopropyl-γ-naphthoxazolyl, 2-3-ethyl-α-naphthoxazolyl , 2-3-methyl-β-naphthoxazolyl, 2-3-sulfopropyl-β-naphthoxazolyl, 2-5-chloro-3-ethyl-α-naphthoxazolyl, 2-5-chloro -3-ethylbenzoxazolyl, 2-5-chloro-3-sulfopropylbenzoxazolyl, 2-5,6-dichloro-3-sulfopropylbenzoxazolyl, 2-5-bromo-3-sulfo Lopylbenzoxazolyl, 2-3-ethyl-5-phenylbenzoxazolyl, 2-5-phenyl-3-sulfopropylbenzoxazolyl, 2-5- (4-bromophenyl) -3-sulfo Butyl benzoxazolyl, 2-5- (1-pyrrolyl) -3-sulfopropylbenzoxazolyl, 2-5,6-dimethyl-3-sulfopropylbenzoxazolyl, 2-3-ethyl-5 Methoxybenzoxazolyl, 2-3-ethyl-5-sulfobenzoxazolyl), thiazole nucleus having 3 to 25 carbon atoms (for example, 2-3-ethylthiazolyl, 2-3-sulfopropylthiazolyl) 2-3-ethylbenzothiazolyl, 2-3-sulfopropylbenzothiazolyl, 2-3-methyl-β-naphthothiazolyl, 2-3-sulfopropyl-γ- Futhiazolyl, 2-3,5-dimethylbenzothiazolyl, 2-5-chloro-3-ethylbenzothiazolyl, 2-5-chloro-3-sulfopropylbenzothiazolyl, 2-3-ethyl-5 -Iodobenzothiazolyl, 2-5-bromo-3-methylbenzothiazolyl, 2-3-ethyl-5-methoxybenzothiazolyl, 2-5-phenyl-3-sulfopropylbenzothiazolyl An imidazole nucleus having 3 to 25 carbon atoms (for example, 2-1,3-diethylimidazolyl, 2-5,6-dichloro-1,3-diethylbenzimidazolyl, 2-5,6-dichloro-3- Ethyl-1-sulfopropylbenzimidazolyl, 2-5-chloro-6-cyano-1,3-diethylbenzimidazolyl, 2-5-chloro-1,3-diethyl-6-trif Such as oromethylbenzimidazolyl), C10-30 indolenine nucleus (for example, 3,3-dimethyl-1-pentylindolenine, 3,3, -dimethyl-1-sulfopropylindolenine, 5-carboxy -1,3,3-trimethylindolenine, 5-carbamoyl-1,3,3-trimethylindolenine, 1,3,3, -trimethyl-4,5-benzoindolenine), C number 9 -25 quinoline nuclei (e.g., 2-1 -ethylquinolyl, 2-1 -sulfobutylquinolyl, 4-1 -pentylquinolyl, 4-1 -sulfoethylquinolyl, 4-1 -methyl-7-chloroquinolyl, ), A C 3-25 selenazole nucleus (for example, 2-3 methylbenzoselenazolyl), a C 5-25 pyri In addition, thiazoline nucleus, oxazoline nucleus, selenazoline nucleus, tellurazoline nucleus, tellurazole nucleus, benzotelrazole nucleus, imidazoline nucleus, imidazo [4,5- Quinoxaline] nucleus, oxadiazole nucleus, thiadiazole nucleus, tetrazole nucleus, pyrimidine nucleus.

These may be substituted. As the substituent (hereinafter referred to as “substituent W”), a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), an alkenyl group (cycloalkenyl group). Group, bicycloalkenyl group), alkynyl group, aryl group, heterocyclic group (may be referred to as heterocyclic group), cyano group, hydroxy group, nitro group, carboxy group, alkoxy group, aryloxy group, silyloxy group , Heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyl group, aryloxycarbonyl group, amino group (including anilino group), ammonio group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonyl Amino group, sulfamoylamino group Alkyl and arylsulfonylamino groups, mercapto groups, alkylthio groups, arylthio groups, heterocyclic thio groups, sulfamoyl groups, sulfo groups, alkyl and arylsulfinyl groups, alkyl and arylsulfonyl groups, acyl groups, aryloxycarbonyl groups, alkoxycarbonyl groups , Carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, phosphono group, silyl group, hydrazino group, ureido group, boronic acid group (-B (OH) ₂ ), phosphato group (—OPO (OH) ₂ ), sulfato group (—OSO ₃ H), and other known substituents.

  These heterocycles may be further condensed. Preferred examples of the condensed ring include a benzene ring, a benzofuran ring, a pyridine ring, a pyrrole ring, an indole ring, and a thiophene ring.

More preferably, the 5- or 6-membered nitrogen-containing heterocyclic ring formed by Z ₁ is an oxazole nucleus, an imidazole nucleus, a thiazole nucleus, or an indolenine nucleus, more preferably an oxazole nucleus or a thiazole nucleus, most preferably Thiazole nucleus and benzothiazole nucleus.

R ₁ represents a hydrogen atom or an alkyl group (preferably having a C number of 1 to 20, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, benzyl, 3-sulfopropyl, 4-sulfobutyl, 3 -Methyl-3-sulfopropyl, 2'-sulfobenzyl, carboxymethyl, 5-carboxypentyl), alkenyl group (preferably C 2-20, for example, vinyl, allyl), aryl group (preferably C 6- 20, for example, phenyl, 2-chlorophenyl, 4-methoxyphenyl, 3-methylphenyl, 1-naphthyl), a heterocyclic group (preferably having 1 to 20 carbon atoms, for example, pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrazolyl) , Pyrrolidino, piperidino, morpholino), more preferably an alkyl group (preferably having a C number of 1 to It is an alkyl group).

L _{11 to} L ₁₄ each represent a methine group and may have a substituent (preferred examples of the substituent are the same as the examples of the substituent on Z ₁ ), and the substituent is preferably an alkyl group or a halogen atom Nitro group, alkoxy group, aryl group, nitro group, heterocyclic group, aryloxy group, acylamino group, carbamoyl group, sulfo group, hydroxy group, carboxy group, alkylthio group, cyano group, etc. An alkyl group is preferred. L _{11 to} L ₁₄ are preferably an unsubstituted methine group or an alkyl group (preferably having a C number of 1 to 6), and more preferably an unsubstituted methine group.
L _{11 to} L ₁₄ may be linked to each other to form a ring, and preferred examples of the ring formed include a cyclohexene ring, a cyclopentene ring, a benzene ring, and a thiophene ring.

p1 is 0 or 1, preferably 0. n1 represents an integer of 0 to 4, more preferably n1 represents 0 to 3, and more preferably n1 represents 1 or 2. When n1 is 2 or more, the plurality of L ₁₃ and L ₁₄ may be the same or different.

  M1 represents an ion for neutralizing the electric charge, and m1 represents a number necessary for neutralizing the electric charge.

Za represents an atomic group forming a 5-membered or 6-membered ring. The ring formed from Za is a part generally called an acidic nucleus, and is defined by James, The Theory of the Photographic Process, 4th edition, Macmillan, 1977, p. 198.
Za is preferably 2-pyrazolone-5-one, pyrazolidine-3,5-dione, imidazolin-5-one, hydantoin, 2 or 4-thiohydantoin, 2-iminooxazolidine-4-one, 2-oxazoline-5 -One, 2-thiooxazoline-2,4-dione, isoxazolone, isorhodanine, rhodanine, indan-1,3-dione, thiophen-3-one, thiophen-3-one-1,1-dioxide, indoline-2 -One, indoline-3-one, 2-oxoindazolium, 5,7-dioxo-6,7-dihydrothiazolo [3,2-a] pyrimidine, 3,4-dihydroisoquinolin-4-one, 1 , 3-Dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, coumarin-2,4-dione, indazo Down 2-one, pyrido [1,2-a] pyrimidine-1,3-dione, pyrazolo [1,5-b] quinazolone include nuclei such pyrazolopyridone.
More preferably, the ring formed from Za is 2-pyrazolone-5-one, pyrazolidine-3,5-dione, isoxazolone, rhodanine, indan-1,3-dione, thiophen-3-one, thiophen-3- On-1,1-dioxide, 1,3-dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid and coumarin-2,4-dione, more preferably isoxazolone and rhodanine Most preferred is rhodanine.

The ring formed from Za may be substituted (preferred examples of the substituent are the same as those of the substituent W on Z ₁ ). More preferably, the substituent is preferably an alkyl group, an aryl group, a heterocyclic group, a halogen. An atom, a cyano group, a carboxyl group, a sulfo group, an alkoxy group, a sulfamoyl group, a carbamoyl group, and an alkoxycarbonyl group. In the case of a heterocyclic group as the substituent, the above substituent may be further substituted, and the case where the heterocyclic group is substituted via an even-numbered methine group (including zero methine) is also preferable (described later) General formula (M-3) reference).

  These heterocycles may be further condensed. Preferred examples of the condensed ring include a benzene ring, a benzofuran ring, a pyridine ring, a pyrrole ring, an indole ring, and a thiophene ring.

Among the dye compounds represented by the general formula (M-1), a dye compound represented by the following general formula (M-2) or general formula (M-3) is preferable.
General formula (M-2)

In formula (M-2), Z ₁ , R ₁ , L _{11 to} L ₁₄ , p 1, n 1, M ₁ and m ₁ have the same meanings as in general formula (M-1). Z ₂ represents an atomic group forming a 5-membered or 6-membered ring, and those listed as Za in the general formula (M-1) are used, preferably rhodanine, hydantoin, thiohydantoin, more preferably rhodanine. It is. R ₂ has the same meaning as R ₁ , and specific examples thereof are also the same, but preferably an alkyl group.
General formula (M-3)

In formula (M-3), Z ₃ , Z ₅ , R ₃ , R ₅ , L _{15 to} L ₂₀ , p2, n2, M ₁ and m ₁ are Z ₁ and Z ₂ in general formula (M-2), respectively. , R ₁ , R ₂ , L _{11 to} L ₁₄ , p 1, n 1, M ₁ and m ₁ . n3 represents 0 or 1. R ₄ has the same meaning as R ₅ . Z ₄ represents an atomic group forming a 5-membered ring, and the 5-membered ring nucleus S or O mentioned as Za in the general formula (M-1) is replaced with a methine group (including a simple double bond). Although used, it is preferable that the S (sulfur atom) position of the rhodanine nucleus and the thiohydantoin nucleus is replaced with a methine group (including a simple double bond). n3 is preferably 0.

  Specific examples of the dye compound represented by formula (M-1) are described below.

  The amorphous film having a composition different from that of the photoelectric conversion film is made of an amorphous substance, and the amorphous substance used may be any inorganic substance, but is preferably an amorphous organic compound. The amorphous film preferably contains at least one compound represented by the following general formula (1).

  Next, the compound represented by the general formula (1) of the present invention will be described in detail.

In formula (1), R _{1 to} R ₁₀ each independently represent a hydrogen atom or a substituent, L represents a monovalent group or a divalent or higher linking group, m represents 0 or 1, and n represents 1 Represents an integer of ~ 4.

In the general formula (1), R _{1 to} R ₁₀ represent a hydrogen atom or a substituent, and the above-described W can be used as the substituent. Preferred examples of the substituent include an alkyl group, an aryl group, and a heterocyclic group, and those represented by W are preferable. More preferably, it is an aryl group or a heterocyclic group. As the aryl group and heterocyclic group, preferably a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole Ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, benzimidazole ring, imidazopyridine ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine Ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, phenanthridine ring, acridine ring, phenanthroline ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothi Or a phenazine ring, more preferably a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyridine ring, an imidazole ring, an oxazole ring, or a thiazole ring, and particularly preferably a benzene ring, a naphthalene ring, or It is a pyridine ring. These rings may further have a substituent, and the substituents may be combined as much as possible to form a ring. R _{1 to} R ₁₀ may be the same or different.
R _{1 to} R ₁₀ may be combined as much as possible to form a ring. Preferably, the ring to be formed is a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine Ring, pyrazine ring, pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, benzimidazole ring, imidazopyridine ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline Ring, quinoxazoline ring, isoquinoline ring, carbazole ring, carboline ring, phenanthridine ring, acridine ring, phenanthroline ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, fe A thiazine ring, phenoxazine ring, phenazine ring, benzimidazolone ring, benzoxazolone ring or benzthiazolone ring, more preferably a benzene ring, naphthalene ring, anthracene ring, pyridine ring, pyrazine ring, pyrimidine ring or pyridazine ring. is there. The formed ring may further have a substituent, and the substituents may be combined as much as possible to form a ring. The case where R ₉ and R ₁₀ form a ring is preferable.

L represents a monovalent group or a divalent or higher linking group. When n is 1, it represents a monovalent group, and the monovalent group represents a hydrogen atom or a substituent. Examples of the substituent include W, but an aryl group or a heterocyclic group is preferable. Examples of the aryl group or heterocyclic group include the examples given for R _{1 to} R ₁₀ . Examples of the compound in this case include compounds (5) and (6) described in paragraph No. 0032 of JP-A No. 11-292848.
The linking group represented by L is preferably a linking group formed of C, N, O, S, Si, and Ge, more preferably a linking group consisting of an aromatic ring and an aromatic heterocycle. A linking group consisting of a benzene ring, a pyridine ring, a pyrimidine ring and a triazine ring is preferred.

  The linking group represented by L may have a substituent, and the substituent represented by the substituent W can be applied as the substituent.

  Specific examples of the linking group represented by L include, but are not limited to, the following. In the following linking group, it is sufficient that the nitrogen-containing heterocycle derived from the general formula (1) is bonded to any two or more of the free bonds, and the nitrogen-containing heterocycle is not bonded. It is only necessary that a substituent such as a hydrogen atom or a substituent W is bonded to the bond.

  m represents 0 or 1, and n represents an integer of 1 to 4. When m is 1, a 5-membered ring including N atom is formed. n is preferably 2 or 3.

The compound represented by the general formula (1) of the present invention is preferably a case represented by the following general formula (2).
General formula (2)

In formula (2), R _{1 to} R ₈ , L, and n are as defined above, and specific examples and preferred examples are also the same. R _{11 to} R ₁₄ have the same meaning as R _{1 to} R ₄ , and specific examples and preferred examples are also the same.

The compound represented by the general formula (1) of the present invention is preferably a case represented by the following general formula (3).
General formula (2)

In formula (3), R _{1 to} R ₈ , L, and n are as defined above, and specific examples and preferred examples are also the same.

  Specific examples of the compound represented by formula (1) preferably used in the present invention are shown below, but the present invention is not limited thereto.

  The compound of the present invention can be synthesized based on the method described in JP-A No. 11-292848.

The photoelectric conversion element of the present invention is characterized in that it is a photoelectric conversion film having a structure in which a crystalline organic photoelectric conversion film and an amorphous film having a composition different from that of the photoelectric conversion film are continuously laminated. When laminating, either may be formed first. The total thickness of the photoelectric conversion film is preferably 100 nm to 500 nm, and the ratio of the thickness of the amorphous film / the thickness of the organic photoelectric conversion film is 0.5 to 1.0, and the preferable ratio is 0.8 to 1.0. It is.
In the present invention, the thickness of the crystalline organic photoelectric conversion film is preferably 30 to 300 nm. When the thickness is larger than 300 nm, the dark current reducing effect of the amorphous film is remarkably reduced in the present invention.

In the present invention, a BGR photoelectric conversion film having good color reproduction, that is, a color 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 laminated can be preferably used. The photoelectric conversion film of the present invention having a structure in which two layers consisting of a crystalline organic photoelectric conversion film and an amorphous film having a composition different from that of the photoelectric conversion film are continuously laminated is selected by selecting a substance to be used. Any film can be prepared, but in the case of the combination of the crystalline merocyanine dye and the compound represented by the general formula (1), it is preferably used as a blue photoelectric conversion film or a green photoelectric conversion film.
The crystalline merocyanine dye and the compound represented by the general formula (1) are preferably used as an organic p-type semiconductor.

[Organic layer]
The organic layer (organic film) in the present invention 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 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. Further, a colorless p-type compound and an n-type compound may be used, and an organic dye may be added thereto.

  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 compounds, benzidine compounds, pyrazoline compounds, styrylamine compounds, hydrazone compounds, triphenylmethane compounds, carbazole compounds, polysilane compounds, thiophene compounds, phthalocyanine compounds, cyanine compounds, merocyanine compounds, oxonol compounds, polyamine compounds, indoles 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, oxa Azole, imidazopyridine, pyralidine, pyrrolopyridine, thiadiazolopyridine, etc.), a polyarylene compound, a fluorene compound, a cyclopentadiene compound, a silyl compound, such as a metal complex having a nitrogen-containing heterocyclic compound as a ligand. 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 organic dye may be used for the organic layer, but it is preferable to use a p-type organic dye or an n-type organic dye. Any organic dye may be used, but preferably a cyanine dye, styryl dye, hemicyanine dye, merocyanine dye (including zero methine merocyanine (simple merocyanine)), trinuclear merocyanine dye, tetranuclear merocyanine dye, Rhodocyanine 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, triphenylmethane dye, azo dye, azomethine dye , Spiro compounds, metallocene dyes, fluorenone dyes, fulgide dyes, perylene dyes, perinone dyes, phenazine dyes, phenothiazine dyes, quinone dyes, diphenylmeta 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 dye, condensation And aromatic carbocyclic dyes (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives).

  As a color imaging device which is one of the objects of the present invention, a cyanine dye, styryl dye, hemicyanine dye, merocyanine dye, trinuclear merocyanine dye, tetranuclear merocyanine dye, rhodacyanine dye having a high degree of freedom in adjusting the absorption wavelength, In some cases, methine dyes such as complex cyanine dyes, complex merocyanine dyes, allopolar dyes, oxonol dyes, hemioxonol dyes, squalium dyes, croconium dyes, and azamethine dyes give preferable wavelength suitability.

Details of these methine dyes are described in the following dye literature.
[Dye literature]
"FM Hemer", "Heterocyclic Compounds-Cyanine Dies and Related Compounds", John Willy and h. & Sons, Inc.-New York, London, 1964, by D.M. Sturmer, "Heterocyclic Compounds in Heterocyclic Compounds-Specialties ins." (heterocyclic chemistry) ", Chapter 18, Section 14, 482-51. 5 pages, John Wiley & Sons-New York, London, 1977, “Rod's Chemistry of Carbon Compounds”, 2nd. Ed. vol. IV, part B, 1977, Chapter 15, pages 369-422, published by Elsevier Science Publishing Company Inc., New York, etc.

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 in the dyes shown in (XI), (XII), (XIII), the number of n ₁₂ , n ₁₅ , n ₁₇ , n ₁₈ is not limited 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.

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” Springer-Verlag H. Examples include the ligands described in Yersin's 1987 issue, “Organometallic Chemistry-Fundamentals and Applications”, Akio Yamamoto's 1982 issue.
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.), aromatic heterocyclic oxy ligands (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, For example, pyridyloxy, 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, 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 and the like, 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, an aromatic heterocyclic oxy group, or a siloxy ligand, Preferably, a nitrogen-containing heterocyclic ligand, an aryloxy ligand, or a siloxy ligand is used.

  In 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, at least one of the p-type semiconductor and the n-type semiconductor The case of a photoelectric conversion film characterized by containing an organic compound whose orientation is controlled in the direction is preferred.

(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 and electron beam heating deposition method, shape of deposition source such as crucible and boat, degree of vacuum, deposition temperature, base temperature, deposition rate, etc. It is a parameter. In order to make uniform deposition possible, it is preferable to perform deposition by rotating the substrate. The degree of vacuum is higher or less preferably ^10- 4 Torr, preferably ^10- 6 Torr or less, and particularly preferably a vacuum vapor deposition below ^10- 8 Torr performed. It is preferable that all steps during the vapor deposition are 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 for vacuum deposition need to be strictly controlled because they affect the crystallinity, amorphousness, density, density, etc. of the organic film. It is preferable to use 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 simultaneously, a co-evaporation method, a flash vapor deposition method, or the like can be preferably used.

[Absorption wavelength regulation]
In the present invention, as described above, a BGR photoelectric conversion film having 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 or more and 500 nm or less, more preferably 420 nm or more. It is a case where it exists in the range of 430 nm or more and 470 nm or less especially preferably. λmax2 and Smax2 are preferably 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 that respectively show 50% of the spectral maximum absorption of λmax1, λmax2, and λmax3 and the spectral maximum sensitivity of Smax1, Smax2, and Smax3. 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.
In addition, 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, which 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.
In addition, 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 the spectral absorption of 50% of the spectral maximum of Smax1, Smax2, Smax3 is 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.

[Organic dye layer thickness regulation]
When the photoelectric conversion film of the present invention is used as a color image sensor (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, 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.

[Voltage application]
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 ⁻² V / cm or more, more preferably 10 V / cm or more, further preferably 1 × 10 ³ V / cm or more, and particularly preferably 1 × 10 ⁴ V / cm. As described above, it is most preferably 1 × 10 ⁵ V / cm 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 10 V / cm or less, preferably more 1 × ¹⁰ 7 V / cm or less.

[General requirements]
In the present invention, it is preferable to use a configuration 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 Laid-Open No. 2005-042356 (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 ) Is preferable. Further, a thin layer of a conductive material may be inserted between the repetitive structures. Silver or gold is preferable as the conductive material, and silver is most preferable. The number of repeating structures (tandem structures) of the pn junction layer may be any number, but is preferably 2 or more and 100 or less, more preferably 2 or more and 50 or less, and particularly preferably 5 in order to increase the photoelectric conversion efficiency. It is 40 or less and most preferably 10 or more and 30 or less.
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 Laid-Open No. 2005-042356 (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 stacked structure is preferable, and a preferred example of the BGR stacked 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 this embodiment. In the solid-state imaging device as shown in FIG. 2, 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 stacked 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 a case where at least two electromagnetic wave absorption / photoelectric conversion sites are included, and at least one of these sites is the photoelectric conversion element (preferably an image sensor) 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 photoelectric conversion element (preferably an image sensor) 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 from 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” supervised by Yutaka Sawada (published by CMC, 2002) ), "Transparent conductive film technology" by the Japan Society for the Promotion of Science (Ohm Co., 1999), and the references attached thereto, etc. can be used. Hereinafter, a method of forming a transparent electrode film using an EB vapor deposition apparatus is referred to as an EB vapor deposition method, and a method of 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 Co., 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 / read-out site is formed, and is usually divided for each pixel. 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 a configuration example of the photoelectric conversion film lamination, first, in the case where there is one organic layer laminated 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 there are two organic layers 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 stacked in order.

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, EB vapor deposition apparatus, and 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), “Transparency 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 as the material 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 dependence of the absorption coefficient of silicon, and color separation is performed in the depth direction. In this case, since color separation is performed based on the light penetration depth of silicon, the spectral range detected by each stacked light receiving unit 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 disposed 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 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 region of the mold and the second conductivity type 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, In _x Ga ₁ - a composition of 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 raw 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, a method of forming a colored layer by providing a mordanting layer made of a hydrophilic polymer material such as gelatin, casein, mulled or polyvinyl alcohol on a substrate and adding or dyeing a dye having a desired absorption wavelength to the mordanting 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 site, reference can be made to JP-A-58-103166, JP-A-58-103165, JP-A-2003-332551, and the like. A configuration in which a MOS transistor is formed in each pixel unit on a semiconductor substrate or a configuration 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 that is two-dimensionally arrayed is known as a CMOS sensor. This is because a switch connected to a pixel connected to the intersection of XY is connected to a vertical shift register, and when a switch is turned on by a voltage from the vertical scanning shift register, it is read from a pixel placed in the same row. The signal is read out to the output line in the column direction. This signal is sequentially read from the output 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 site 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, element formation material By repeated operation of arrangement (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 to 10 microns, but 3 to 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. Further, 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 omitted, and higher sensitivity and higher 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 subjects that are moving, '' and other shooting 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 the photoelectric conversion element to be exchanged, an exchange photoelectric conversion element can be prepared for 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 TV Information Technology Society, Television Camera Design Technology (August 20, 1999, Corona, ISBN 4-339-00714-5). Fig. 2.1 The television camera can be manufactured by replacing the part of 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. Although the pixel electrode 14 is a transparent electrode, a part such as aluminum or molybdenum is often 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 total thickness of the organic layer composed of 7, 8, 9, 10 is preferably 0.5 μm or less, more preferably 0.4 μm or less, and particularly preferably 0.3 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 at the time of forming a resist pattern at the time of forming connection electrodes such as 18 and 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. 3 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.

  The cleaned ITO substrate is placed in a vapor deposition apparatus, and an amorphous organic compound (2) is deposited to 100 nm at room temperature, followed by 100 nm of a crystalline organic dye (MS-1), and then patterned on an organic thin film. A mask (a mask having a light receiving area of 2 mm × 2 mm) was placed, and aluminum was deposited by 100 nm to produce a photoelectric conversion element (element 1).

  A device was prepared in the same manner as in the device of Example 1 except that the organic dye (MS-2) of the present invention was used instead of the organic dye (MS-1) of the present invention (device 2).

  A device was prepared in the same manner as in the device of Example 1 except that the organic dye (MS-3) of the present invention was used instead of the organic dye (MS-1) of the present invention (device 3).

A device was prepared in the same manner as in the device of Example 1 except that the organic dye (MS-4) of the present invention was used instead of the organic dye (MS-1) of the present invention (device 4).
[Comparative example]
A device was manufactured in the same manner as in the device of Example 1 except that the compound (2) of the present invention was not used (device 5).

Next, each element was evaluated as follows.
For each element, the characteristics when the ITO side was minus and the aluminum electrode side was plus and a 5 V bias was applied to the element were evaluated.
These results are shown in Table 1.
The devices 1, 2, 3, and 4 of this example all exhibited a high S / N ratio with respect to the comparative device 5.

By using the element of the present invention of Example 1 for the G film shown in FIG. 2, a color imaging element exhibiting excellent color separation can be produced.
When the photoelectric conversion site that absorbs the G light of Example 1 or 2 is used in the portions 8 and 9 of the photoelectric conversion site in FIG. 3, a color imaging device exhibiting excellent color separation can be manufactured.

It is sectional drawing which shows roughly the structure of the organic photoelectric conversion element of this invention. It is a cross-sectional schematic diagram of a preferable image sensor according to the present invention. It is a cross-sectional schematic diagram for 1 pixel of the photoelectric conversion element of BGR 3 layer lamination by this invention.

Explanation of symbols

201 Substrate 202 Electrode 203 Photoelectric conversion layer 204 Electrode 1 Antireflection film 2 Infrared cut dielectric multilayer films 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 substrate 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 read pad 101 P well layers 102, 104, 106 High-concentration impurity regions 103, 105, 107 MOS circuit 108 Gate insulating film 109, 110 Insulating films 111, 114, 116, 119, 121, 124, transparent electrode films 112, 117 , 122, electrodes 113, 118, 123 photoelectric conversion films 110, 115, 20,125 transparent insulating film 126 light shielding film 150 a semiconductor substrate

Claims (7)

  A photoelectric conversion element having a structure in which a crystalline organic photoelectric conversion film and an amorphous film having a composition different from that of the photoelectric conversion film are continuously laminated.   The photoelectric conversion element according to claim 1, wherein the organic photoelectric conversion film is made of a crystalline merocyanine dye.   The photoelectric conversion element according to claim 1, wherein the amorphous film is made of an organic compound. The photoelectric conversion element according to claim 1, wherein the amorphous film contains at least one compound represented by the following general formula (1).

In formula (1), R _{1 to} R ₁₀ each independently represent a hydrogen atom or a substituent, L represents a monovalent group or a divalent or higher linking group, m represents 0 or 1, and n represents 1 Represents an integer of ~ 4.   The photoelectric conversion element according to claim 1, wherein the thickness of the amorphous film / the thickness of the organic photoelectric conversion film is 1 or less.   The photoelectric conversion element according to claim 5, wherein the organic photoelectric conversion film and the amorphous film are formed by a vacuum deposition method.   An image pickup device comprising the photoelectric conversion device according to claim 1.

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