JP2013055248A - Manufacturing method of photoelectric conversion element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a photoelectric conversion element capable of minimizing degradation of performance due to the manufacturing process while reducing the manufacturing cost.SOLUTION: The manufacturing method of a photoelectric conversion element comprising a first electrode, a second electrode formed above the first electrode, an organic layer formed between the first and second electrodes and having a photoelectric conversion layer generating charges in response to the received light, and a sealing layer for sealing the first and second electrodes and the organic layer includes: an organic layer formation step for forming the organic layer above the first electrode; a second electrode formation step for forming the second electrode above the organic layer; and a sealing layer formation step for forming the sealing layer above the second electrode. Each step from the organic layer formation step to the sealing layer formation step is carried out under vacuum. Furthermore, a step for placing an intermediate product of photoelectric conversion element in the way of production under non-vacuum with irradiation intensity of 300 lux h or less is provided between the organic layer formation step and the second electrode formation step.

Description

  The present invention relates to a method for manufacturing a photoelectric conversion element including an organic layer having a photoelectric conversion layer that generates a charge in response to received light, and particularly suppresses performance degradation due to a manufacturing process while suppressing manufacturing cost. The present invention relates to a method for manufacturing a photoelectric conversion element.

  Currently, a photoelectric conversion element having a pair of electrodes and a photoelectric conversion layer using an organic material provided between the pair of electrodes is known. Patent Document 1 discloses a photoelectric conversion element using fullerene or a fullerene derivative as a photoelectric conversion layer for the purpose of improving photoelectric conversion efficiency.

JP 2007-123707 A

In general, it is known that characteristics of organic materials change due to the influence of moisture and oxygen. For this reason, when manufacturing a photoelectric conversion element, it has been considered as common sense that it is desirable to perform all the processes in a consistent vacuum.
On the other hand, if it is going to implement | achieve a vacuum consistent process, since manufacturing facilities will become large, there exists a concern that the manufacturing cost of a photoelectric conversion element may increase. Therefore, there has been a demand for a method for obtaining a photoelectric conversion element having no performance deterioration while suppressing the manufacturing cost.

  The objective of this invention is providing the manufacturing method of the photoelectric conversion element which can suppress the problem based on the said prior art, and can suppress the performance degradation resulting from a manufacturing process, suppressing manufacturing cost.

In order to achieve the above object, the present invention provides a first electrode, a second electrode formed above the first electrode, and a gap formed between the first electrode and the second electrode. The photoelectric conversion element which has the organic layer which has the photoelectric converting layer which produces | generates an electric charge according to the received light, and the sealing layer which seals the 1st electrode, the 2nd electrode, and the organic layer The organic layer forming step of forming the organic layer above the first electrode, the second electrode forming step of forming the second electrode above the organic layer, A sealing layer forming step of forming the sealing layer above the second electrode, and each step from the organic layer forming step to the sealing layer forming step is performed under vacuum, Between the organic layer forming step and the second electrode forming step, 300 l of the intermediate of the photoelectric conversion element in the process of manufacture is added. There is provided a method of manufacturing a photoelectric conversion element characterized by comprising the step of placing the non-vacuum of x · h following irradiation light amount.
In the present invention, non-vacuum means an environment where both oxygen and water are 1000 ppm or more.

Prior to the organic layer forming step, a first electrode forming step of forming the first electrode above the substrate may be included.
For example, the organic layer forming step includes a step of forming an electron blocking layer on the first electrode and a step of forming the photoelectric conversion layer on the electron blocking layer.
The step of placing under non-vacuum is preferably performed with an irradiation light amount of 200 lux · h or less. The photoelectric conversion layer preferably has a bulk heterostructure of a p-type organic semiconductor and an n-type organic semiconductor.

  Furthermore, it is preferable that the p-type organic semiconductor contains a compound represented by the general formula (1). The n-type organic semiconductor preferably contains fullerene or a fullerene derivative.

In the general formula (1), Z ₁ represents a ring containing at least two carbon atoms and represents a 5-membered ring, a 6-membered ring, or a condensed ring containing at least one of a 5-membered ring and a 6-membered ring. L ₁ , L ₂ , and L ₃ each independently represent an unsubstituted methine group or a substituted methine group. D ₁ represents an atomic group. n represents an integer of 0 or more.

  ADVANTAGE OF THE INVENTION According to this invention, the performance deterioration of the photoelectric conversion element resulting from a manufacturing process can be suppressed, suppressing manufacturing cost. Furthermore, it is possible to obtain an imaging device and an imaging device that have a predetermined performance with performance degradation suppressed.

It is typical sectional drawing which shows the photoelectric conversion element of embodiment of this invention. It is a typical sectional view showing an image sensor of an embodiment of the present invention. (A)-(c) is typical sectional drawing which shows the manufacturing method of the image pick-up element of embodiment of this invention in order of a process. (A)-(c) is typical sectional drawing which shows the manufacturing method of the image pick-up element of embodiment of this invention in order of a process, and shows the post process of FIG.3 (c).

  Below, based on suitable embodiment shown to an accompanying drawing, the manufacturing method of the photoelectric conversion element of this invention is demonstrated in detail.

In the photoelectric conversion element 100 illustrated in FIG. 1, a first electrode 104 is formed over a substrate 102, and an organic layer 106 is formed over the first electrode 104. A second electrode 108 is formed on the organic layer 106. An organic layer 106 is provided between the first electrode 104 and the second electrode 108. The organic layer 106 includes a photoelectric conversion layer 112 and an electron blocking layer 114, and the electron blocking layer 114 is formed on the first electrode 104.
A sealing layer 110 that seals the first electrode 104, the second electrode 108, and the organic layer 106 is provided so as to cover the second electrode 108.

As the substrate 102, a silicon substrate, a glass substrate, or the like can be used.
The first electrode 104 is an electrode for collecting holes out of charges generated in the organic layer 106 (photoelectric conversion layer 112). The first electrode 104 is made of a conductive material such as TiN (titanium nitride).
As the substrate 102, for example, a TiN substrate on which a TiN electrode is formed is preferably used as the first electrode 104.

  The photoelectric conversion layer 112 of the organic layer 106 receives light and generates an electric charge according to the amount of light, and includes an organic photoelectric conversion material. For example, the photoelectric conversion layer 112 has a bulk heterostructure in which a p-type organic semiconductor (p-type organic compound) and a fullerene or a fullerene derivative that is an n-type organic semiconductor are mixed. Note that details of the photoelectric conversion layer 112 will be described later.

The electron blocking layer 114 is a layer for preventing electrons from being injected into the organic layer 106 from the first electrode 104, and is composed of a single layer or a plurality of layers. The electron blocking layer 114 may be composed of a single organic material film, or may be composed of a mixed film of a plurality of different organic materials. The electron blocking layer 114 is preferably made of a material having a high electron injection barrier from the adjacent first electrode 104 and a high hole transporting property. As an electron injection barrier, the electron affinity of the electron blocking layer 114 is preferably 1 eV or less, more preferably 1.3 eV or more, and particularly preferably 1.5 eV or more than the work function of the adjacent electrode.
The electron blocking layer 114 is 20 nm or more in order to sufficiently suppress the contact between the first electrode 104 and the organic photoelectric conversion layer 112 and avoid the influence of defects and dust existing on the surface of the first electrode 104. Is more preferably 40 nm or more, and particularly preferably 60 nm or more.
If the electron blocking layer 114 is made too thick, the problem that the supply voltage is increased to apply an appropriate electric field strength to the organic photoelectric conversion layer 112 and the carrier transport process in the electron blocking layer 114 are There arises a problem that adversely affects the performance of the conversion element. The total thickness of the electron blocking layer 114 is preferably 300 nm or less, more preferably 200 nm or less, and still more preferably 100 nm or less.

  The second electrode 108 is an electrode that collects electrons out of charges generated in the organic layer 106. For the second electrode 108, a conductive material (for example, ITO) that is sufficiently transparent with respect to light having a wavelength with which the organic layer 106 has sensitivity is used in order to make light incident on the organic layer 106. By applying a bias voltage between the second electrode 108 and the first electrode 104, out of charges generated in the organic layer 106, holes move to the first electrode 104 and electrons move to the second electrode 108. Can be made.

  The sealing layer 110 is a layer for preventing a factor that degrades an organic material such as water or oxygen from entering the organic layer 106 containing the organic material. The sealing layer 110 covers the first electrode 104, the electron blocking layer 114, the organic layer 106, and the second electrode 108, and is sealed between the substrate 102.

  In the photoelectric conversion element 100 configured as described above, the second electrode 108 is used as a light incident side electrode. When light enters from above the second electrode 108, the light is transmitted through the second electrode 108. The light is incident on the organic layer 106 where charge is generated. Holes in the generated charges move to the first electrode 104. By converting the holes that have moved to the first electrode 104 into a voltage signal corresponding to the amount of the holes and reading out the light, the light can be converted into a voltage signal and extracted.

  The electron blocking layer 114 may be a plurality of layers. By using a plurality of layers, an interface is formed between the layers constituting the electron blocking layer 114, and discontinuity occurs in the intermediate level existing in each layer. As a result, it becomes difficult for the charge to move through the intermediate level, and the electron blocking effect can be enhanced. However, if the layers constituting the electron blocking layer 114 are made of the same material, the intermediate levels existing in the layers may be exactly the same. Therefore, in order to further enhance the electron blocking effect, the materials constituting the layers are different. It is preferable to make it.

Next, a method for manufacturing the photoelectric conversion element 100 will be described.
In addition, in the manufacturing method of the photoelectric conversion element 100 of this invention, the intermediate body (photoelectric conversion element intermediate body) which is a feedstock for manufacturing the photoelectric conversion element 100, or an intermediate product in the middle of manufacture is conveyed by a predetermined | prescribed path | route. Various layers and films are formed by various methods on the conveyed feedstock or intermediate, but even if there is no particular explanation, the transport path and the formation environment of the various layers and films The space may be maintained at a predetermined degree of vacuum by an evacuation unit (not shown) or the like. That is, even if there is no description in particular, various layers and films may be formed and transported under vacuum with respect to the feedstock or intermediate (photoelectric conversion element intermediate).

First, as the first electrode 104, for example, a TiN substrate in which a TiN electrode is formed on the substrate 102 is prepared.
In the TiN substrate, for example, TiN is formed as a first electrode material on the substrate 102 by a sputtering method under a predetermined vacuum, and a TiN electrode is formed as the first electrode 104.
Instead of using the TiN substrate, for example, the first electrode 104 may be formed on the substrate 102 by, for example, forming a film of TiN under a predetermined vacuum by a sputtering method.

  Next, an electron blocking material, for example, a carbazole derivative, more preferably a bifluorene derivative, is formed on the first electrode 104 under a predetermined vacuum using, for example, a vapor deposition method to form the organic layer 106. The electron blocking layer 114 is formed.

Next, on the electron blocking layer 114, as a photoelectric conversion material, for example, a p-type organic semiconductor and fullerene or a fullerene derivative are vapor-deposited using a vapor deposition method under a predetermined vacuum, and the organic layer 106 is formed. A constituent photoelectric conversion layer 112 is formed (an organic layer forming step).
Next, a second electrode material, for example, ITO is formed on the photoelectric conversion layer 112 under a predetermined vacuum using a sputtering method to form the second electrode 108 (second electrode formation step). .
Next, a sealing material, for example, Al ₂ O ₃ (alumina) is formed over the second electrode 108 and the substrate 102 under a predetermined vacuum by using, for example, a vapor deposition method to form the sealing layer 110. Form (sealing layer forming step).

In the manufacturing method of the present embodiment, in each step of the organic layer forming step including the step of forming the electron blocking layer 114 and the step of forming the photoelectric conversion layer 112, the second electrode forming step, and the sealing layer forming step, In order to prevent degradation factors of the organic film such as water and oxygen from entering the film and deteriorating the properties of the film in the film, the above-mentioned manufacturing processes and the transportation between the manufacturing processes are performed under a predetermined vacuum. We are carrying out.
The electron blocking layer 114 and the photoelectric conversion layer 112 can be formed in the same film formation chamber or in separate film formation chambers. In the case of separate film formation chambers, after the electron blocking layer 114 is formed, the transport when forming the photoelectric conversion layer 112 is also performed under a predetermined vacuum.
Until now, when the intermediate product in the middle of production is placed in a non-vacuum between the formation of the photoelectric conversion layer 112 and the formation of the second electrode 108, the photoelectric conversion layer 112, In some cases, it was considered that the organic material constituting the electron blocking layer 114 deteriorates and the performance of the photoelectric conversion element deteriorates.

However, as a result of intensive studies, the present inventor has performed irradiation even if an intermediate product in the middle of production is placed in a non-vacuum state after the photoelectric conversion layer 112 is formed and before the second electrode 108 is formed. It has been found that if the amount of light is 300 lux · h or less, the element performance of the finally produced photoelectric conversion element 100 does not deteriorate. The amount of irradiation light is preferably 200 lux · h or less, and ideally the amount of irradiation light is zero.
Here, the irradiation light quantity is a value measured using a W lamp fluorescent lamp as a light source and using an illuminometer under the W lamp fluorescent lamp. The irradiation light amount of the present invention is a value converted to a W lamp fluorescent lamp.
Moreover, under non-vacuum is an environment where both oxygen and water are 1000 ppm or more.
Furthermore, it has been found that if oxygen and water are both 100 ppm or less, there is no performance deterioration due to light irradiation. Under vacuum, in a predetermined vacuum state, both oxygen and water are 100 ppm or less.

  In the manufacturing method according to the present embodiment, a period of exposure under non-vacuum (hereinafter referred to as the period between the formation process of the photoelectric conversion layer 112 (organic layer formation process) and the formation process of the second electrode 108 (second electrode formation process) , Also referred to as a non-vacuum period). For this reason, it is not necessary to transport the intermediate body (photoelectric conversion element intermediate body) in a vacuum state between the apparatus for forming the photoelectric conversion layer 112 and the apparatus for forming the second electrode 108. As a result, the manufacturing facility for the photoelectric conversion element 100 can be simplified, and the manufacturing cost can be reduced. In addition, performance degradation of the finally manufactured photoelectric conversion element 100 is suppressed.

Next, an image sensor using the photoelectric conversion element 100 will be described.
FIG. 2 is a schematic cross-sectional view showing the image sensor of the embodiment of the present invention. 3 and 4 are schematic cross-sectional views illustrating the method of manufacturing the image sensor according to the embodiment of the present invention in the order of steps.
The image sensor according to the embodiment of the present invention can be used in an imaging apparatus such as a digital camera or a digital video camera. Furthermore, it is used by being mounted on an imaging module such as an electronic endoscope and a cellular phone.

2 includes a substrate 12, an insulating layer 14, a pixel electrode 16, an organic layer 18, a counter electrode 20, a sealing layer (protective film) 22, a stress relaxation layer 24, a color A filter 26, a partition wall 28, a light shielding layer 29, and a protective layer 30 are included.
Note that the pixel electrode 16 corresponds to the first electrode 104 of the photoelectric conversion element 100 shown in FIG. 1 described above, and the counter electrode 20 corresponds to the second electrode 108 of the photoelectric conversion element 100 described above. Reference numeral 18 corresponds to the organic layer 106 of the photoelectric conversion element 100 described above, and the sealing layer 22 corresponds to the sealing layer 110 of the photoelectric conversion element 100 described above. A reading circuit 40 and a counter electrode voltage supply unit 42 are formed on the substrate 12.

As the substrate 12, for example, a glass substrate or a semiconductor substrate such as Si is used. An insulating layer 14 made of a known insulating material is formed on the substrate 12. A plurality of pixel electrodes 16 are formed on the surface of the insulating layer 14. The pixel electrodes 16 are arranged in a one-dimensional or two-dimensional manner, for example.
In addition, a first connection portion 44 that connects the pixel electrode 16 and the readout circuit 40 is formed in the insulating layer 14. Furthermore, a second connection portion 46 that connects the counter electrode 20 and the counter electrode voltage supply unit 42 is formed. The second connection portion 46 is formed at a position not connected to the pixel electrode 16 and the organic layer 18. The 1st connection part 44 and the 2nd connection part 46 are formed with the electroconductive material.
In addition, a wiring layer 48 made of a conductive material for connecting the readout circuit 40 and the counter electrode voltage supply unit 42 to, for example, the outside of the imaging device 10 is formed inside the insulating layer 14.
As described above, the circuit board 11 is formed by forming the pixel electrodes 16 connected to the first connection portions 44 on the surface 14 a of the insulating layer 14 on the substrate 12. The circuit board 11 is also referred to as a CMOS substrate.

  The organic layer 18 is formed so as to cover the plurality of pixel electrodes 16 and to avoid the second connection portion 46. The organic layer 18 includes a photoelectric conversion layer 50 and an electron blocking layer 52. Since the organic layer 18 corresponds to the organic layer 106 of the photoelectric conversion element 100 shown in FIG. 1 as described above, the photoelectric conversion layer 50 and the electron blocking layer 52 are the photoelectric conversion layer 112 and the electron blocking layer 114, respectively. It goes without saying that it corresponds to.

In the organic layer 18, the electron blocking layer 52 is formed on the pixel electrode 16 side, and the photoelectric conversion layer 50 is formed on the electron blocking layer 52.
The electron blocking layer 52 is a layer for suppressing injection of electrons from the pixel electrode 16 to the photoelectric conversion layer 50.
The photoelectric conversion layer 50 generates charges according to the amount of received light such as incident light L, and includes an organic photoelectric conversion material. As long as the photoelectric conversion layer 50 and the electron blocking layer 52 have a constant film thickness on the pixel electrode 16, the film thickness may not be constant in other cases. The photoelectric conversion layer 50 will be described in detail later.

The counter electrode 20 is an electrode facing the pixel electrode 16 and is provided so as to cover the photoelectric conversion layer 50. A photoelectric conversion layer 50 is provided between the pixel electrode 16 and the counter electrode 20.
The counter electrode 20 is made of a conductive material that is transparent to incident light so that light enters the photoelectric conversion layer 50. The counter electrode 20 is electrically connected to the second connection portion 46 disposed outside the photoelectric conversion layer 50, and is connected to the counter electrode voltage supply portion 42 via the second connection portion 46. Yes.

  Examples of the material of the counter electrode 20 (second electrode 108) include metals, metal oxides, metal nitrides, metal borides, organic conductive compounds, and mixtures thereof. Specific examples include tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), indium tungsten oxide (IWO), conductive metal oxides such as titanium oxide, and metal nitrides such as TiN. Metal, gold (Au), platinum (Pt), silver (Ag), chromium (Cr), nickel (Ni), aluminum (Al), etc., and a mixture or laminate of these metals and conductive metal oxides Products, organic conductive compounds such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO. Particularly preferable materials for the transparent conductive film are ITO, IZO, tin oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), zinc oxide, antimony-doped zinc oxide (AZO), gallium-doped zinc oxide ( GZO). A particularly preferable material among the materials of the counter electrode 20 (second electrode 108) is ITO.

  The counter electrode voltage supply unit 42 applies a predetermined voltage to the counter electrode 20 via the second connection unit 46. When the voltage to be applied to the counter electrode 20 is higher than the power supply voltage of the image sensor 10, the power supply voltage is boosted by a booster circuit such as a charge pump to supply the predetermined voltage.

  The pixel electrode 16 is an electrode for collecting charges for collecting charges generated in the photoelectric conversion layer 50 between the pixel electrode 16 and the counter electrode 20 facing the pixel electrode 16. The pixel electrode 16 is connected to the readout circuit 40 via the first connection portion 44. The readout circuit 40 is provided on the substrate 12 corresponding to each of the plurality of pixel electrodes 16, and reads out a signal corresponding to the charge collected by the corresponding pixel electrode 16.

  Examples of the material of the pixel electrode 16 (first electrode 104) include metals, metal oxides, metal nitrides, metal borides, organic conductive compounds, and mixtures thereof. Specific examples include tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), indium tungsten oxide (IWO), conductive metal oxides such as titanium oxide, and metal nitrides such as TiN. Metal, gold (Au), platinum (Pt), silver (Ag), chromium (Cr), nickel (Ni), aluminum (Al), etc., and a mixture or laminate of these metals and conductive metal oxides Products, organic conductive compounds such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO. Particularly preferable materials for the transparent conductive film are ITO, IZO, tin oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), zinc oxide, antimony-doped zinc oxide (AZO), gallium-doped zinc oxide ( GZO). Of the materials of the pixel electrode 16 (first electrode 104), a particularly preferable material is TiN.

  A step corresponding to the film thickness of the pixel electrode 16 is steep at the end of the pixel electrode 16, there are significant irregularities on the surface of the pixel electrode 16, or minute dust (particles) adhere to the pixel electrode 16. As a result, a layer on the pixel electrode 16 becomes thinner than a desired film thickness or a crack occurs. When the counter electrode 20 (second electrode 108) is formed on the layer in such a state, pixel defects such as an increase in dark current and a short circuit are caused by contact between the pixel electrode 16 and the counter electrode 20 in the defective portion or electric field concentration. Occur. Further, the above-described defects may reduce the adhesion between the pixel electrode 16 and the layer above it and the heat resistance of the organic photoelectric conversion element 10.

  In order to prevent the above defects and improve the reliability of the element, the surface roughness Ra of the pixel electrode 16 is preferably 0.6 nm or less. The smaller the surface roughness Ra of the pixel electrode 16, the smaller the surface unevenness, and the better the surface flatness. In order to remove particles on the pixel electrode 16, it is particularly preferable to clean the pixel electrode 16 and the like using a general cleaning technique used in a semiconductor manufacturing process before forming the electron blocking layer 52. preferable.

The readout circuit 40 is constituted by, for example, a CCD, a MOS circuit, or a TFT circuit, and is shielded from light by a light shielding layer (not shown) provided in the insulating layer 14. The readout circuit 40 preferably employs a CCD or CMOS circuit for general image sensor applications, and preferably employs a CMOS circuit from the viewpoint of noise and high speed.
Although not shown, for example, a high-concentration n region surrounded by a p region is formed on the substrate 12, and a connection portion 44 is connected to the n region. A read circuit 40 is provided in the p region. The n region functions as a charge storage unit that stores the charge of the photoelectric conversion layer 50. The electric charge accumulated in the n region is converted into a signal corresponding to the amount of electric charge by the readout circuit 40 and output to the outside of the image sensor 10 through the wiring layer 48, for example.

The sealing layer (protective film) 22 is for protecting the photoelectric conversion layer 50 containing an organic substance from deterioration factors such as water molecules. The sealing layer 22 is formed so as to cover the counter electrode 20.
The following conditions are required for the sealing layer 22 (sealing layer 110).
First, it is possible to protect the photoelectric conversion layer by preventing intrusion of factors that degrade the organic photoelectric conversion material contained in the solution, plasma, and the like in each manufacturing process of the device.
Secondly, after the device is manufactured, the intrusion of factors such as water molecules that degrade the organic photoelectric conversion material is prevented, and deterioration of the photoelectric conversion layer 50 is prevented over a long period of storage / use.
Third, when the sealing layer 22 is formed, the already formed photoelectric conversion layer is not deteriorated.
Fourth, since incident light reaches the photoelectric conversion layer 50 through the sealing layer 22, the sealing layer 22 must be transparent to light having a wavelength detected by the photoelectric conversion layer 50.

  The sealing layer 22 can be composed of a thin film made of a single material. However, by providing a separate function for each layer in a multi-layer structure, stress relaxation of the entire sealing layer 22 and generation of dust during the manufacturing process. Such effects as the suppression of defects such as cracks and pinholes caused by the above, and the optimization of material development can be expected. For example, the sealing layer 22 is formed by laminating a “sealing auxiliary layer” having a function that is difficult to achieve on the layer that serves the original purpose of preventing the penetration of deterioration factors such as water molecules. A two-layer structure can be formed. Although it is possible to have three or more layers, it is preferable that the number of layers is as small as possible in consideration of manufacturing costs.

The stress relaxation layer 24 is formed on the sealing layer 22 so as to cover the sealing layer 22.
The sealing layer 22 is provided to relieve the internal stress when the internal stress is a tensile stress and the magnitude thereof is large. For example, it is formed by a physical vapor deposition (PVD) method such as sputtering, and is composed of ceramics such as a metal oxide, a metal nitride, and a metal nitride oxide.
The stress relaxation layer 24 relieves the stress of the entire sealing layer 22 and increases the reliability of the sealing layer 22 itself, and also deteriorates the performance of the photoelectric conversion layer 50 and the like due to the stress of the sealing layer 22 and sealing. Generation | occurrence | production of defects, such as destroying the photoelectric converting layer 50 with the stress of the stop layer 22, can be suppressed notably.

Moreover, the sealing layer 22 (sealing layer 110) can be formed as follows, for example.
The performance of organic photoelectric conversion materials is significantly deteriorated due to the presence of deterioration factors such as water molecules. Therefore, it is necessary to cover and seal the entire photoelectric conversion layer with a dense metal oxide film, metal nitride film, metal oxynitride film, or the like that does not allow water molecules to permeate. Conventionally, aluminum oxide, silicon oxide, silicon nitride, silicon nitride oxide, a laminated structure thereof, a laminated structure of them and an organic polymer, or the like is used as a sealing layer by various vacuum film forming techniques. The conventional sealing layer is a film compared to the flat part because the growth of the thin film is difficult (because the step becomes a shadow) at the step due to structures on the substrate surface, minute defects on the substrate surface, particles adhering to the substrate surface, etc. The thickness is significantly reduced. For this reason, the step portion becomes a path through which the deterioration factor penetrates. In order to completely cover this step with the sealing layer 22, it is necessary to form the film so as to have a film thickness of 1 μm or more in the flat portion, thereby increasing the thickness of the entire sealing layer 22.

  In the image sensor 10 having a pixel size of less than 2 μm, particularly about 1 μm, if the distance between the color filter 28 and the photoelectric conversion layer 50, that is, the film thickness of the sealing layer 22 is large, incident light is diffracted in the sealing layer 22. Or it diverges and color mixing occurs. For this reason, the imaging element 10 having a pixel size of about 1 μm requires a sealing layer material and a manufacturing method thereof that do not deteriorate the element performance even when the film thickness of the entire sealing layer 22 is reduced.

  The atomic layer deposition (ALD) method is a kind of CVD method, and adsorption / reaction of organometallic compound molecules, metal halide molecules, and metal hydride molecules, which are thin film materials, onto the substrate surface and unreacted groups contained therein. Is a technique for forming a thin film by alternately repeating decomposition. When the thin film material reaches the substrate surface, it is in the above-mentioned low molecular state, so that the thin film can be grown in a very small space where the low molecule can enter. For this reason, the step portion, which was difficult with the conventional thin film formation method, is completely covered (the thickness of the thin film grown on the step portion is the same as the thickness of the thin film grown on the flat portion), that is, the step coverage is very high. Excellent. For this reason, steps due to structures on the substrate surface, minute defects on the substrate surface, particles adhering to the substrate surface, and the like can be completely covered, and such a step portion does not become an intrusion path for a deterioration factor of the photoelectric conversion material. When the sealing layer 22 is formed by an atomic layer deposition (ALD) method, the required sealing layer thickness can be reduced more effectively than in the prior art.

  When the sealing layer 22 is formed by the atomic layer deposition method, a material corresponding to the above-described preferable sealing layer can be appropriately selected. However, it is limited to a material capable of growing a thin film at a relatively low temperature so that the organic photoelectric conversion material does not deteriorate. According to the atomic layer deposition method using alkyl aluminum or aluminum halide as the material, a dense aluminum oxide thin film can be formed at less than 200 ° C. at which the organic photoelectric conversion material does not deteriorate. In particular, when trimethylaluminum is used, an aluminum oxide thin film can be formed even at about 100 ° C., which is preferable. Silicon oxide and titanium oxide are also preferable because a dense thin film can be formed as the sealing layer 22 at a temperature lower than 200 ° C., similarly to aluminum oxide, by appropriately selecting materials.

  The thin film formed by the atomic layer deposition method can achieve a high-quality thin film formation at a low temperature that is unmatched from the viewpoint of step coverage and denseness. However, the thin film may be deteriorated by chemicals used in the photolithography process. For example, since an aluminum oxide thin film formed by atomic layer deposition is amorphous, the surface is eroded by an alkaline solution such as a developer or a stripping solution. In such a case, a thin film having excellent chemical resistance is required on the aluminum oxide thin film formed by the atomic layer deposition method. That is, the stress relaxation layer 24 (sealing auxiliary layer) serving as a functional layer for protecting the sealing layer 22 is necessary.

  In particular, a second sealing layer (stress relaxation) formed by sputtering on the first sealing layer (sealing layer 22) and containing any one of aluminum oxide, silicon oxide, silicon nitride, and silicon nitride oxide. It is preferable to have a structure having a layer 24). Moreover, it is preferable that the sealing layer 22 (first sealing layer) has a film thickness of 0.05 μm or more and 0.2 μm or less. Furthermore, the sealing layer 22 (first sealing layer) preferably contains any of aluminum oxide, silicon oxide, and titanium oxide.

  The color filter 26 is formed at a position facing each pixel electrode 16 on the stress relaxation layer 24. The partition wall 28 is provided between the color filters 26 on the stress relaxation layer 24 and is for improving the light transmission efficiency of the color filter 26. The light shielding layer 29 is formed in a region other than the region (effective pixel region) in which the color filter 26 and the partition wall 28 are provided on the sealing layer 22, and light is incident on the photoelectric conversion layer 50 formed outside the effective pixel region. This is to prevent this.

The protective layer 30 is for protecting the color filter 26 from subsequent processes and is formed so as to cover the color filter 26, the partition wall 28 and the light shielding layer 29. The protective layer 30 is also referred to as an overcoat layer.
In the image sensor 10, one pixel electrode 16 having the organic layer 18, the counter electrode 20, and the color filter 26 provided thereon is a unit pixel.

  The protective layer 30 can be appropriately made of a polymer material such as acrylic resin, polysiloxane resin, polystyrene resin, or fluorine resin, or an inorganic material such as silicon oxide or silicon nitride. When a photosensitive resin such as polystyrene is used, the protective layer 30 can be patterned by a photolithography method, so that it can be used as a photoresist when opening the peripheral light shielding layer, sealing layer, insulating layer, etc. on the bonding pad. The protective layer 30 itself can be easily processed as a microlens, which is preferable. On the other hand, it is possible to use the protective layer 30 as an antireflection layer, and it is also preferable to form various low refractive index materials used as the partition walls of the color filter 26. In addition, in order to pursue a function as a protective layer and a function as an antireflection layer with respect to a subsequent process, the protective layer 30 can be configured to have two or more layers combining the above materials.

  In the present embodiment, the pixel electrode 16 is configured on the surface of the insulating layer 14, but the configuration is not limited to this, and the pixel electrode 16 may be embedded in the surface portion of the insulating layer 14. Moreover, although the structure which provides the 2nd connection part 46 and the counter electrode voltage supply part 42 was made, it may be plural. For example, a voltage drop at the counter electrode 20 can be suppressed by supplying a voltage from both ends of the counter electrode 20 to the counter electrode 20. The number of sets of the second connection unit 46 and the counter electrode voltage supply unit 42 may be appropriately increased or decreased in consideration of the chip area of the element.

Next, a manufacturing method of the image sensor 10 according to the embodiment of the present invention will be described.
In addition, in the manufacturing method of the image sensor 10 of the present invention, a feedstock for manufacturing the image sensor 10 or an intermediate product in the middle of manufacture is transported through a predetermined path, and the supplied feedstock or intermediate product is transported. Various layers and films are formed by various methods, but even if not specifically described, the transport path and the formation environment and space of the various layers and films are predetermined by a vacuum exhaust means (not shown). There is a case where the degree of vacuum is maintained. That is, even if there is no description in particular, various layers and films may be formed and transported under vacuum with respect to the feedstock or the intermediate product being manufactured.

  In the method for manufacturing the image sensor 10 according to the embodiment of the present invention, first, as shown in FIG. 3A, the first circuit is formed on the substrate 12 on which the readout circuit 40 and the counter electrode voltage supply unit 42 are formed. The insulating layer 14 provided with the connecting portion 44, the second connecting portion 46, and the wiring layer 48 is formed, and the pixel electrode 16 connected to each first connecting portion 44 is further formed on the surface 14 a of the insulating layer 14. A formed circuit board 11 (CMOS substrate) is prepared. In this case, as described above, the first connection unit 44 and the readout circuit 40 are connected, and the second connection unit 46 and the counter electrode voltage supply unit 42 are connected. The pixel electrode 16 is made of, for example, TiN.

  Next, the electron blocking layer 52 is transferred to a film forming chamber (not shown) through a predetermined transfer path, and as shown in FIG. 3B, all the pixel electrodes except for the second connection portion 46 are used. 16, an electron blocking material is deposited under a predetermined vacuum by using, for example, a vapor deposition method to form the electron blocking layer 52. As the electron blocking material, for example, a carbazole derivative, more preferably a bifluorene derivative is used. It moves to the formation process of the photoelectric conversion layer 50 of the next process.

Next, the film is transferred to a film formation chamber (not shown) of the photoelectric conversion layer 50 through a predetermined transfer path, and, for example, a p-type organic semiconductor is formed on the surface 52a of the electron blocking layer 52 as shown in FIG. And fullerene or a fullerene derivative are formed under a predetermined vacuum using a vapor deposition method. Thereby, the photoelectric conversion layer 50 is formed and the organic layer 18 is formed. As shown in FIG. 3C, an intermediate product for manufacturing the image sensor 10 is referred to as an intermediate body 13 (photoelectric conversion element intermediate body).
The electron blocking layer 52 and the photoelectric conversion layer 50 can be formed in the same film formation chamber or in separate film formation chambers. In the case of separate film forming chambers, after the electron blocking layer 52 is formed, conveyance when forming the photoelectric conversion layer 50 is also performed under a predetermined vacuum.
Further, the organic layer forming step includes a forming step of the electron blocking layer 50 and a forming step of the photoelectric conversion layer 52.

Next, the intermediate body 13 is transferred to the next step of forming the counter electrode 20, that is, when it is transported to a film forming chamber (not shown) of the counter electrode 20 through a predetermined transport path, in a non-vacuum state. Transport. In this case, the amount of light in the non-vacuum environment, that is, the amount of irradiation light in the environment to which the intermediate 13 is exposed is set to 300 lux · h or less. Preferably, the amount of light in the non-vacuum environment, that is, the amount of irradiation light in the environment to which the intermediate 13 is exposed is 200 lux · h or less, and ideally, the amount of light in the non-vacuum environment (irradiation light amount) is zero. It is.
Deterioration in the manufacturing process of the image sensor 10 can be suppressed by setting the amount of light in the environment under non-vacuum, that is, the amount of irradiation light in the environment to which the intermediate 13 is exposed to 300 lux · h or less.

Next, after transporting to a film forming chamber (not shown) of the counter electrode 20 through a predetermined transport path, as shown in FIG. 4A, the photoelectric conversion layer 18 is covered and the second connection portion 46 is covered. The counter electrode 20 is formed in a predetermined vacuum by a sputtering method, for example, with the pattern formed in (1). For example, ITO is used as the counter electrode material. The process proceeds to the next step of forming the sealing layer 22.
Next, it is transferred to a film forming chamber (not shown) for the sealing layer 22 through a predetermined transfer path, and as shown in FIG. 4B, the surface 14a of the insulating layer 14 is covered so as to cover the counter electrode 20. In addition, the sealing layer 22 is formed under a predetermined vacuum by, for example, an atomic layer deposition (ALD) method. For example, Al ₂ O ₃ (alumina) is used as the sealing material. The process proceeds to the process of forming the stress relaxation layer 24 in the next process.

Next, the stress relaxation layer 24 is transported to a film forming chamber (not shown) through a predetermined transport path, and the stress relaxation layer 24 is formed on the surface 22a of the sealing layer 22 as shown in FIG. For example, it is formed under a predetermined vacuum by a sputtering method. For example, SiON (silicon oxynitride) is used as the stress relaxation material.
Next, the color filter 26, the partition wall 28, and the light shielding layer 29 are formed on the surface 24a of the stress relaxation layer 24 by using, for example, a photolithography method. As the color filter 26, the partition wall 28, and the light shielding layer 29, known ones used for organic solid-state imaging devices are used. The formation process of the color filter 26, the partition wall 28, and the light shielding layer 29 may be under non-vacuum.
Next, the protective film 30 is formed using, for example, a coating method so as to cover the color filter 26, the partition wall 28, and the light shielding layer 29. Thereby, the image sensor 10 shown in FIG. 2 can be formed. As the protective film 30, a known film used for an organic solid-state imaging device is used. The formation process of the protective film 30 may be under non-vacuum.

Also in the manufacturing process of the image sensor 10, the intermediate 13 is placed under non-vacuum between the process of forming the photoelectric conversion layer 50 (organic layer forming process) and the process of forming the counter electrode 20 (second electrode forming process). A step of placing, that is, a non-vacuum period is provided. This eliminates the need for the transfer path from the film forming chamber for forming the photoelectric conversion layer 50 to the film forming chamber for forming the counter electrode 20 to be in a vacuum state. As a result, the manufacturing equipment for the image sensor 10 can be simplified, and as a result, the manufacturing cost can be reduced. In addition, the finally manufactured image sensor 10 is one in which performance degradation is suppressed.
In the present embodiment, for example, there may be a step of forming the pixel electrode 16 using TiN as a pixel electrode material under a predetermined vacuum by a sputtering method.
In the present embodiment, the organic layer forming step to the second electrode forming step are performed under vacuum, but reactive sputtering can also be used for each forming step. In the reactive sputtering method, for example, oxygen gas is introduced into the film forming chamber. If the atmosphere in the film forming chamber before supply of the oxygen gas is vacuum, it is assumed that the gas is formed under vacuum.

Next, the photoelectric conversion layer 50 and the electronic block king layer 52 constituting the organic layer 18 will be described in detail.
The photoelectric conversion layer 50 includes a p-type organic semiconductor and an n-type organic semiconductor. Exciton dissociation efficiency can be increased by joining a p-type organic semiconductor and an n-type organic semiconductor to form a donor-acceptor interface. For this reason, the photoelectric conversion layer of the structure which joined the p-type organic semiconductor and the n-type organic semiconductor expresses high photoelectric conversion efficiency. In particular, a photoelectric conversion layer in which a p-type organic semiconductor and an n-type organic semiconductor are mixed is preferable because the junction interface is increased and the photoelectric conversion efficiency is improved.

  In the present embodiment, the photoelectric conversion layer 50 preferably has a layer having a bulk heterojunction structure including a p-type semiconductor and an n-type semiconductor. Thus, by having a bulk heterojunction structure, the shortcoming of the short carrier diffusion length of the photoelectric conversion layer 50 can be compensated, and the photoelectric conversion efficiency of the photoelectric conversion layer 50 can be improved. The bulk heterojunction structure is described in detail in Japanese Patent Application Laid-Open No. 2005-303266.

  The thickness of the photoelectric conversion layer 50 is preferably 10 nm or more and 1000 nm or less, more preferably 50 nm or more and 800 nm or less, and particularly preferably 100 nm or more and 500 nm or less. By setting the thickness of the photoelectric conversion layer 50 to 10 nm or more, a suitable dark current suppressing effect is obtained, and by setting the thickness of the photoelectric conversion layer 50 to 1000 nm or less, suitable photoelectric conversion efficiency is obtained.

  A p-type organic semiconductor (compound) is a donor-type organic semiconductor (compound), which is mainly represented by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound. For example, triarylamine compound, benzidine compound, pyrazoline compound, styrylamine compound, hydrazone compound, triphenylmethane compound, carbazole compound, polysilane compound, thiophene compound, phthalocyanine compound, cyanine compound, merocyanine compound, oxonol compound, polyamine compound, indole Compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives), nitrogen-containing heterocyclic compounds The metal complex etc. which have 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.

  An n-type organic semiconductor (compound) is an acceptor organic semiconductor, and is mainly represented by an electron-transporting organic compound and refers to an organic compound having a property of easily accepting electrons. More specifically, an n-type organic semiconductor refers to an organic compound having a larger 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, oxy Diazole, imidazopyridine, pyralidine, pyrrolopyridine, thiadiazolopyridine, dibenzazepine, tribenzazepine, etc.), polyarylene compounds, fluorene compounds, cyclopentadiene compounds, silyl compounds, nitrogen-containing heterocyclic compounds as ligands Etc. Not limited to this, as described above, any organic compound having an electron affinity higher than that of the organic compound used as the p-type (donor property) compound may be used as the acceptor organic semiconductor.

  Any organic dye may be used as the p-type organic semiconductor or the n-type organic semiconductor, but preferably a cyanine dye, a styryl dye, a hemicyanine dye, a merocyanine dye (including zero methine merocyanine (simple merocyanine)), 3 Nuclear merocyanine dye, 4-nuclear merocyanine dye, rhodacyanine dye, complex cyanine dye, complex merocyanine dye, allopolar dye, oxonol dye, hemioxonol dye, squalium dye, croconium dye, azamethine dye, coumarin dye, arylidene dye, anthraquinone dye, tri Phenylmethane dye, azo dye, azomethine dye, spiro compound, metallocene dye, fluorenone dye, fulgide dye, perylene dye, perinone dye, phenazine dye, phenothiazine Dye, quinone dye, diphenylmethane dye, polyene dye, acridine dye, acridinone dye, diphenylamine dye, quinacridone dye, quinophthalone dye, phenoxazine dye, phthaloperylene dye, diketopyrrolopyrrole dye, dioxane dye, porphyrin dye, chlorophyll dye, phthalocyanine dye , Metal complex dyes, condensed aromatic carbocyclic dyes (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives).

As the n-type organic semiconductor, it is particularly preferable to use fullerene or a fullerene derivative having excellent electron transport properties. The fullerene, fullerene _{C 60,} fullerene _{C 70,} fullerene _{C 76,} fullerene _{C 78,} fullerene _{C 80,} fullerene _{C 82,} fullerene _{C 84,} fullerene _{C 90,} fullerene _{C 96,} fullerene _{C 240,} fullerene _{C 540,} mixed Fullerene and fullerene nanotube are represented, and a fullerene derivative represents a compound having a substituent added thereto.

  The substituent for the fullerene derivative is preferably an alkyl group, an aryl group, or a heterocyclic group. The alkyl group is more preferably an alkyl group having 1 to 12 carbon atoms, and the aryl group and the heterocyclic group are preferably 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, phenanthroli Ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, or phenazine ring, more preferably a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyridine ring, imidazole ring, oxazole ring, Or a thiazole ring, particularly preferably a benzene ring, a naphthalene ring, or a pyridine ring. These may further have a substituent, and the substituents may be bonded as much as possible to form a ring. In addition, you may have a some substituent and they may be the same or different. A plurality of substituents may be combined as much as possible to form a ring.

  When the photoelectric conversion layer contains fullerene or a fullerene derivative, electrons generated by photoelectric conversion can be quickly transported to the pixel electrode 16 or the counter electrode 20 via the fullerene molecule or fullerene derivative molecule. When fullerene molecules or fullerene derivative molecules are connected to form an electron path, the electron transport property is improved, and high-speed response of the photoelectric conversion element can be realized. For this purpose, the fullerene or fullerene derivative is preferably contained in the photoelectric conversion layer by 40% (volume ratio) or more. However, if there are too many fullerenes or fullerene derivatives, the p-type organic semiconductor will decrease, the junction interface will become smaller, and the exciton dissociation efficiency will decrease.

  In the photoelectric conversion layer 50, when a triarylamine compound described in Japanese Patent No. 4213832 is used as a p-type organic semiconductor mixed with fullerene or a fullerene derivative, a high SN ratio of the photoelectric conversion element can be expressed. Particularly preferred. If the ratio of fullerene or fullerene derivative in the photoelectric conversion layer is too large, the amount of triarylamine compounds decreases and the amount of incident light absorbed decreases. As a result, the photoelectric conversion efficiency is reduced. Therefore, the fullerene or fullerene derivative contained in the photoelectric conversion layer preferably has a composition of 85% (volume ratio) or less.

  The p-type organic semiconductor material used for the photoelectric conversion layer 50 is preferably a compound represented by the following general formula (1).

In the general formula (1), Z ₁ represents a ring containing at least two carbon atoms and represents a 5-membered ring, a 6-membered ring, or a condensed ring containing at least one of a 5-membered ring and a 6-membered ring. . L ₁ , L ₂ , and L ₃ each independently represent an unsubstituted methine group or a substituted methine group. D ₁ represents an atomic group. n represents an integer of 0 or more.

Z ₁ is a ring containing at least two carbon atoms, and represents a 5-membered ring, a 6-membered ring, or a condensed ring containing at least one of a 5-membered ring and a 6-membered ring. As a condensed ring containing at least one of a 5-membered ring, a 6-membered ring, and a 5-membered ring and a 6-membered ring, those usually used as an acidic nucleus in a merocyanine dye are preferable, and specific examples thereof include the following: Is mentioned.

(A) 1,3-dicarbonyl nucleus: For example, 1,3-indandione nucleus, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 1,3-dioxane-4,6- Zeon etc.
(B) pyrazolinone nucleus: for example 1-phenyl-2-pyrazolin-5-one, 3-methyl-1-phenyl-2-pyrazolin-5-one, 1- (2-benzothiazoyl) -3-methyl-2 -Pyrazolin-5-one and the like.
(C) Isoxazolinone nucleus: For example, 3-phenyl-2-isoxazolin-5-one, 3-methyl-2-isoxazolin-5-one and the like.
(D) Oxindole nucleus: For example, 1-alkyl-2,3-dihydro-2-oxindole and the like.
(E) 2,4,6-triketohexahydropyrimidine nucleus: for example, barbituric acid or 2-thiobarbituric acid and its derivatives. Examples of the derivatives include 1-alkyl compounds such as 1-methyl and 1-ethyl, 1,3-dialkyl compounds such as 1,3-dimethyl, 1,3-diethyl and 1,3-dibutyl, 1,3-diphenyl, 1,3-diaryl compounds such as 1,3-di (p-chlorophenyl) and 1,3-di (p-ethoxycarbonylphenyl), 1-alkyl-1-aryl compounds such as 1-ethyl-3-phenyl, Examples include 1,3-di (2-pyridyl) 1,3-diheterocyclic substituents and the like.
(F) 2-thio-2,4-thiazolidinedione nucleus: for example, rhodanine and derivatives thereof. Examples of the derivatives include 3-alkylrhodanine such as 3-methylrhodanine, 3-ethylrhodanine and 3-allylrhodanine, 3-arylrhodanine such as 3-phenylrhodanine, and 3- (2-pyridyl) rhodanine. And the like.

(G) 2-thio-2,4-oxazolidinedione (2-thio-2,4- (3H, 5H) -oxazoledione nucleus: for example, 3-ethyl-2-thio-2,4-oxazolidinedione and the like.
(H) Tianaphthenone nucleus: For example, 3 (2H) -thianaphthenone-1,1-dioxide and the like.
(I) 2-thio-2,5-thiazolidinedione nucleus: for example, 3-ethyl-2-thio-2,5-thiazolidinedione and the like.
(J) 2,4-thiazolidinedione nucleus: For example, 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, 3-phenyl-2,4-thiazolidinedione, and the like.
(K) Thiazolin-4-one nucleus: For example, 4-thiazolinone, 2-ethyl-4-thiazolinone and the like.
(L) 2,4-imidazolidinedione (hydantoin) nucleus: for example, 2,4-imidazolidinedione, 3-ethyl-2,4-imidazolidinedione, etc.
(M) 2-thio-2,4-imidazolidinedione (2-thiohydantoin) nucleus: for example, 2-thio-2,4-imidazolidinedione, 3-ethyl-2-thio-2,4-imidazolidinedione etc.
(N) Imidazolin-5-one nucleus: for example, 2-propylmercapto-2-imidazolin-5-one and the like.
(O) 3,5-pyrazolidinedione nucleus: for example, 1,2-diphenyl-3,5-pyrazolidinedione, 1,2-dimethyl-3,5-pyrazolidinedione and the like.
(P) Benzothiophen-3-one nucleus: for example, benzothiophen-3-one, oxobenzothiophen-3-one, dioxobenzothiophen-3-one and the like.
(Q) Indanone nucleus: For example, 1-indanone, 3-phenyl-1-indanone, 3-methyl-1-indanone, 3,3-diphenyl-1-indanone, 3,3-dimethyl-1-indanone and the like.

The ring formed by Z ₁ is preferably a 1,3-dicarbonyl nucleus, a pyrazolinone nucleus, a 2,4,6-triketohexahydropyrimidine nucleus (including a thioketone body, for example, a barbituric acid nucleus, 2-thiobarbitur tool) Acid nucleus), 2-thio-2,4-thiazolidinedione nucleus, 2-thio-2,4-oxazolidinedione nucleus, 2-thio-2,5-thiazolidinedione nucleus, 2,4-thiazolidinedione nucleus, 2, In 4-imidazolidinedione nucleus, 2-thio-2,4-imidazolidinedione nucleus, 2-imidazolin-5-one nucleus, 3,5-pyrazolidinedione nucleus, benzothiophen-3-one nucleus, indanone nucleus More preferably 1,3-dicarbonyl nucleus, 2,4,6-triketohexahydropyrimidine nucleus (including thioketone, for example, barbituric acid nucleus, 2-thiovale nucleus, Bituric acid nucleus), 3,5-pyrazolidinedione nucleus, benzothiophen-3-one nucleus, indanone nucleus, more preferably 1,3-dicarbonyl nucleus, 2,4,6-triketohexahydropyrimidine Nuclei (including thioketone bodies, such as barbituric acid nuclei, 2-thiobarbituric acid nuclei), particularly preferably 1,3-indandione nuclei, barbituric acid nuclei, 2-thiobarbituric acid nuclei and derivatives thereof. is there.

L ₁ , L ₂ , and L ₃ each independently represent an unsubstituted methine group or a substituted methine group. The substituted methine groups may be bonded to each other to form a ring (eg, a 6-membered ring such as a benzene ring). Although the substituent of the substituted methine group includes the substituent W, it is preferable that all of L ₁ , L ₂ and L ₃ are unsubstituted methine groups.
L _{1 to} L ₃ 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.

  n represents an integer of 0 or more, preferably 0 or more and 3 or less, and more preferably 0. When n is increased, the absorption wavelength region can be made longer, or the thermal decomposition temperature is lowered. N = 0 is preferable in that it has appropriate absorption in the visible region and suppresses thermal decomposition during vapor deposition.

D ₁ represents an atomic group. D ₁ is preferably ^a group containing —NR ^a (R ^b ), and more preferably —NR ^a (R ^b ) represents an arylene group substituted. R ^a and R ^b each independently represent a hydrogen atom or a substituent.

The arylene group represented by D ₁ is preferably an arylene group having 6 to 30 carbon atoms, and more preferably an arylene group having 6 to 18 carbon atoms. The arylene group may have a substituent W described later, and is preferably an arylene group having 6 to 18 carbon atoms which may have an alkyl group having 1 to 4 carbon atoms. Examples thereof include a phenylene group, a naphthylene group, an anthracenylene group, a pyrenylene group, a phenanthrenylene group, a methylphenylene group, and a dimethylphenylene group, and a phenylene group or a naphthylene group is preferable.

Examples of the substituent represented by R ^a or R ^b include the substituent W described later, and preferably an aliphatic hydrocarbon group (preferably an alkyl group or alkenyl group which may be substituted) or an aryl group (preferably a substituent). A phenyl group which may be substituted), or a heterocyclic group.

The aryl groups represented by R ^a and R ^b are each independently preferably an aryl group having 6 to 30 carbon atoms, and more preferably an aryl group having 6 to 18 carbon atoms. The aryl group may have a substituent, and is preferably an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 18 carbon atoms which may have an aryl group having 6 to 18 carbon atoms. . Examples thereof include a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, a methylphenyl group, a dimethylphenyl group, and a biphenyl group, and a phenyl group or a naphthyl group is preferable.

The heterocyclic groups represented by R ^a and R ^b are preferably each independently a heterocyclic group having 3 to 30 carbon atoms, and more preferably a heterocyclic group having 3 to 18 carbon atoms. The heterocyclic group may have a substituent, preferably a C3-C18 heterocyclic group which may have a C1-C4 alkyl group or a C6-C18 aryl group. It is. The heterocyclic group represented by R ^a and R ^b is preferably a condensed ring structure, and furan ring, thiophene ring, selenophene ring, silole ring, pyridine ring, pyrazine ring, pyrimidine ring, oxazole ring, thiazole ring, triazole. A condensed ring structure of a ring combination selected from a ring, an oxadiazole ring, and a thiadiazole ring (which may be the same) is preferable. A quinoline ring, an isoquinoline ring, a benzothiophene ring, a dibenzothiophene ring, a thienothiophene ring, and a bithienobenzene ring A bithienothiophene ring is preferred.

The arylene group and aryl group represented by D ₁ , R ^a and R ^b are preferably a benzene ring or a condensed ring structure, more preferably a condensed ring structure containing a benzene ring, a naphthalene ring, an anthracene ring, pyrene A benzene ring, a naphthalene ring or an anthracene ring, more preferably a benzene ring or a naphthalene ring.

As the substituent W, a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), an alkynyl group, an aryl group, and a heterocyclic group (May be referred to as a 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, aryl Oxycarbonyl group, amino group (including anilino group), ammonio group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercap Group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic ring 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), a sulfato group (-OSO ₃ H), and other known substituents.

When R ^a and R ^b represent a substituent (preferably an alkyl group or an alkenyl group), the substituent is an aromatic ring (preferably benzene ring) skeleton of an aryl group substituted by —NR ^a (R ^b ). It may combine with a hydrogen atom or a substituent to form a ring (preferably a 6-membered ring).
R ^a and R ^b may be bonded to each other to form a ring (preferably a 5-membered or 6-membered ring, more preferably a 6-membered ring), and R ^a and R ^b are each L A ring (preferably a 5-membered or 6-membered ring, more preferably a 6-membered ring) may be formed by combining with a substituent in (represents any one of L ₁ , L ₂ , and L ₃ ).

  The compound represented by the general formula (1) is a compound described in JP 2000-297068 A, and a compound not described in the above publication can also be produced according to the synthesis method described in the above publication. . The compound represented by the general formula (1) is preferably a compound represented by the general formula (2).

In General Formula (2), Z ₂ , L ₂₁ , L ₂₂ , L ₂₃ , and n are synonymous with Z ₁ , L ₁ , L ₂ , L ₃ , and n in General Formula (1), and preferred examples thereof Is the same. D ₂₁ represents a substituted or unsubstituted arylene group. D ₂₂ and D ₂₃ each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group.

The arylene group represented by D ₂₁ has the same meaning as the arylene ring group represented by D ₁ , and preferred examples thereof are also the same. The aryl group represented by D ₂₂ and D ₂₃ is independently the same as the heterocyclic group represented by R ^a and R ^b , and preferred examples thereof are also the same.

  Although the preferable specific example of a compound represented by General formula (1) below is shown using General formula (3), this invention is not limited to these.

In General Formula (3), Z ₃ represents any one of A-1 to A-12 in Chemical Formula 5 shown below. L ₃₁ represents methylene and n represents 0. D ₃₁ is any one of B-1 to B-9, and D ₃₂ and D ₃₃ each represent any one of C-1 to C-16. Z ₃ is preferably A-2, D ₃₂ and D ₃₃ are preferably selected from C-1, C-2, C-15, and C-16, and D ₃₁ is B-1 or B- 9 is preferred.

  Particularly preferred p-type organic materials include dyes or materials not having 5 or more condensed ring structures (materials having 0 to 4, preferably 1 to 3 condensed ring structures). When using a pigment-based p-type material generally used in organic thin-film solar cells, the dark current tends to increase at the pn interface, and the light response is slow due to trapping at the crystalline grain boundary. Since it tends to be, it is difficult to use for an image sensor. For this reason, a dye-based p-type material that is difficult to crystallize, or a material that does not have five or more condensed ring structures can be preferably used for the imaging element.

  More preferred specific examples of the compound represented by the general formula (1) are combinations of the substituents, linking groups and partial structures shown below in the general formula (3), but the present invention is not limited to these. Absent.

  In addition, A-1 to A-12, B-1 to B-9, and C-1 to C-16 in the chemical formula 6 are the same as those shown in the chemical formula 5. Although the especially preferable specific example of a compound represented by General formula (1) below is shown, this invention is not limited to these.

(Molecular weight)
The compound represented by the general formula (1) preferably has a molecular weight of 300 or more and 1500 or less, more preferably 350 or more and 1200 or less, and more preferably 400 or more and 900 or less, from the viewpoint of film forming suitability. Further preferred. When the molecular weight is too small, the film thickness of the formed photoelectric conversion film decreases due to volatilization. Conversely, when the molecular weight is too large, vapor deposition cannot be performed, and a photoelectric conversion element cannot be manufactured.

(Melting point)
The compound represented by the general formula (1) has a melting point of preferably 200 ° C. or higher, more preferably 220 ° C. or higher, and further preferably 240 ° C. or higher from the viewpoint of vapor deposition stability. If the melting point is low, it melts before vapor deposition, and in addition to being unable to form a stable film, the decomposition product of the compound increases, so the photoelectric conversion performance deteriorates.

(Absorption spectrum)
The peak wavelength of the absorption spectrum of the compound represented by the general formula (1) is preferably 400 nm or more and 700 nm or less, more preferably 480 nm or more and 700 nm or less, more preferably 510 nm or more and 680 nm, from the viewpoint of broadly absorbing light in the visible region. More preferably, it is as follows.

(Molar extinction coefficient of peak wavelength)
The higher the molar extinction coefficient is, the better the compound represented by the general formula (1) is from the viewpoint of efficiently using light. Absorption spectrum (chloroform solution), in the visible region of the wavelength 400nm to 700 nm, the molar absorption coefficient preferably ²⁰⁰⁰⁰ -1 ^{cm -1} or more, more preferably ^{30000 m} -1 ^{cm -1} or more, ^{40000M -1 cm} -1 or more Is more preferable.

  An electron donating organic material can be used for the electron blocking layer 52. Specifically, in a low molecular material, N, N′-bis (3-methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (TPD) or 4,4′-bis [N Aromatic diamine compounds such as-(naphthyl) -N-phenyl-amino] biphenyl (α-NPD), oxazole, oxadiazole, triazole, imidazole, imidazolone, stilbene derivative, pyrazoline derivative, tetrahydroimidazole, polyarylalkane, butadiene 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) N-phenylamino) triphenylamine (m-MTDATA), porphine, tetraphenylporphine copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, etc. Polyphyrin compounds, triazole derivatives, oxa Zazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, annealing amine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, carbazole derivatives, bifluorenes Derivatives can be used, and as the polymer material, polymers such as phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, diacetylene, and derivatives thereof can be used. Even if it is not an ionic compound, it can be used as long as it is a compound having sufficient hole transportability.

  The present invention is basically configured as described above. As mentioned above, although the manufacturing method of the photoelectric conversion element of this invention was demonstrated in detail, this invention is not limited to the said embodiment, You may make various improvement or change in the range which does not deviate from the main point of this invention. Of course.

Hereinafter, in the present invention, the effect of setting the light irradiation amount to 300 lux · h or less under non-vacuum will be specifically described. In this Example, Examples 1 to 6 and Comparative Examples shown in Table 1 below using Compound 1 (500 to 600 nm), Compound 2 (600 to 700 nm) and Compound 3 (400 to 500 nm) having different absorption wavelengths. The image sensors of 1 to 8 and Reference Examples 1 to 3 were produced, and the effects of the present invention were confirmed.
In addition, the non-vacuum shown in the following Table 1 is an environment in which both oxygen and water are 1000 ppm or more as described above. The amount of irradiation light shown in Table 1 below is a value measured using a W lamp fluorescent lamp as a light source and using an illuminometer under the W lamp fluorescent lamp.

In this example, in order to confirm the effect of the present invention, the relative sensitivities of Examples 1 to 6 and Comparative Examples 1 to 8 were measured. The results are shown in Table 1 below.
In Reference Example 1, the compounds of the photoelectric conversion layer were the same as in Examples 1 and 2 and Comparative Examples 1 to 4, and these were used as the reference. In Reference Example 2, the compounds of the photoelectric conversion layer were the same as Examples 3 and 4, Comparative Examples 5 and 6, and these were used as the reference. In Reference Example 3, the compounds of the photoelectric conversion layer were the same as in Examples 5 and 6, and Comparative Examples 7 and 8, and these were used as the reference.
The relative sensitivities shown in Table 1 below are obtained by setting the numerical values of Reference Example 1, Reference Example 2, and Reference Example 3 to 100, respectively.

Relative sensitivity measured the value of the external quantum efficiency at the maximum sensitivity wavelength when applied to the image sensors of Examples 1 to 6 and Comparative Examples 1 to 8 with an electric field of 2 × 10 ⁵ V / cm. This is obtained by dividing the value of the external quantum efficiency by the value of the external quantum efficiency of each of reference examples 1 to 3 serving as a reference. That is, the relative sensitivity is the value of the external quantum efficiency of Examples 1 to 6 and Comparative Examples 1 to 8 / the value of the external quantum efficiency of Reference Examples 1 to 3 serving as each reference.
In addition, the value of external quantum efficiency is 2 * 10 < ⁵ > V / cm on the counter electrode of each image pick-up element of Examples 1-6 produced and Comparative Examples 1-8 using the quantum efficiency measuring apparatus (IPCE). This is a value calculated from the current value obtained when an external electric field is applied.
Hereinafter, the image sensors of Examples 1 to 6, Comparative Examples 1 to 8, and Reference Examples 1 to 3 will be described.

Example 1
First, the CMOS substrate on which the pixel electrode was formed was moved to the organic vapor deposition chamber, the CMOS substrate was attached to the substrate holder, and the pressure in the chamber was reduced to 1 × 10 ⁻⁴ Pa or less. After that, while rotating the substrate holder, vapor deposition was performed on the pixel electrode by a resistance heating vapor deposition method using Compound 4 as an electron blocking material so as to have a thickness of 1000 mm at a deposition rate of 1.0 to 1.2 mm / Sec. A blocking layer was formed.
Next, compound 1 and fullerene C ₆₀ (denoted as C _{60 in} Table 1 below) are deposited at a deposition rate of 1.6 to 1.8 Å / Sec and 2.5 to 2.8 Å / Sec, respectively, so that the thickness becomes 4000 Å. The photoelectric conversion layer was formed by vapor deposition. Thereby, the thing equivalent to the intermediate body 13 shown in FIG.3 (c) is obtained.
Next, after placing the intermediate under non-vacuum irradiation with light of 300 lux · h, the intermediate is transported to the sputtering chamber, the sputtering chamber is brought to a predetermined degree of vacuum, and ITO is then deposited on the photoelectric conversion layer. Sputtering was performed to a thickness of 100 mm by RF magnetron sputtering to form a counter electrode. After that, after transporting to the ALD chamber and making the ALD chamber have a predetermined degree of vacuum, an Al ₂ O ₃ (alumina) film is formed to a thickness of 2000 mm by the ALD method, and a sealing layer (protective film) is formed. Formed. Thereafter, the film was transferred to a sputtering chamber, and after the inside of the sputtering chamber was set to a predetermined degree of vacuum, a SiON film was formed to a thickness of 1000 mm by RF magnetron sputtering to form a stress relaxation layer.
In addition, after forming a photoelectric converting layer, it was maintained at the predetermined | prescribed vacuum degree between each process except during transferring to the sputtering chamber which forms a counter electrode.

(Example 2)
An imaging device was manufactured in the same manner as in Example 1 except that the light irradiation amount under non-vacuum was changed to 200 lux · h.
(Example 3)
An imaging device was produced in the same manner as in Example 1 except that Compound 1 was changed to Compound 2.
Example 4
An imaging device was produced in the same manner as in Example 1 except that Compound 1 was changed to Compound 2 and the light irradiation amount under non-vacuum was changed to 200 lux · h.
(Example 5)
An imaging device was produced in the same manner as in Example 1 except that Compound 1 was changed to Compound 3.
(Example 6)
An imaging device was produced in the same manner as in Example 1 except that Compound 1 was changed to Compound 3 and the amount of light irradiation under non-vacuum was changed to 200 lux · h.

(Comparative Example 1)
An imaging device was manufactured in the same manner as in Example 1 except that the light irradiation amount under non-vacuum was changed to 500 lux · h.
(Comparative Example 2)
An imaging device was manufactured in the same manner as in Example 1 except that the light irradiation amount under non-vacuum was changed to 1250 lux · h.
(Comparative Example 3)
An imaging device was manufactured in the same manner as in Example 1 except that the light irradiation amount under non-vacuum was changed to 2500 lux · h.
(Comparative Example 4)
An imaging device was manufactured in the same manner as in Example 1 except that the light irradiation amount under non-vacuum was changed to 5000 lux · h.
(Comparative Example 5)
An imaging device was produced in the same manner as in Comparative Example 1 except that Compound 1 was changed to Compound 2.
(Comparative Example 6)
An imaging device was produced in the same manner as in Comparative Example 1 except that Compound 1 was changed to Compound 2 and the light irradiation amount under non-vacuum was changed to 1250 lux · h.
(Comparative Example 7)
An imaging device was produced in the same manner as in Comparative Example 1 except that Compound 1 was changed to Compound 3.
(Comparative Example 8)
An imaging device was produced in the same manner as in Comparative Example 1 except that Compound 1 was changed to Compound 3 and the light irradiation amount under non-vacuum was changed to 1250 lux · h.

(Reference Example 1)
After forming the photoelectric conversion layer, the environment during the transfer to the sputtering chamber for forming the counter electrode was under N ₂ gas (nitrogen gas), and the light irradiation amount was changed to 5000 lux · h, and Example 1 and An image sensor was produced in the same manner.
(Reference example 2)
An imaging device was produced in the same manner as in Reference Example 1 except that Compound 1 was changed to Compound 2.
(Reference example 3)
An imaging device was produced in the same manner as in Reference Example 1 except that Compound 1 was changed to Compound 3.

As shown in Table 1 above, from the comparison between Examples 1 and 2 and Comparative Examples 1 to 4, no sensitivity deterioration was observed at a light irradiation amount of 300 lux · h or less under non-vacuum, and the sensitivity was not seen at 200 lux · h. An improvement was seen.
Further, from the comparison between Examples 3 and 4 and Comparative Examples 5 and 6, the same result as that of Compound 1 was obtained with Compound 2 having a different absorption wavelength.
From the comparison between Examples 5 and 6 and Comparative Examples 6 and 7, the same result as that of Compound 1 was obtained for Compound 3 having a different absorption wavelength.
Further, from Reference Examples 1 to 3, no deterioration in sensitivity is observed under nitrogen gas without depending on the light irradiation amount and the type of compound (absorption wavelength).

DESCRIPTION OF SYMBOLS 10 Image pick-up element 12 Board | substrate 14 Insulation layer 16 Pixel electrode 18, 106 Organic layer 20 Counter electrode 22 Sealing layer 24 Stress relaxation layer 26 Color filter 30 Protection layer 40 Read-out circuit 42 Counter electrode voltage supply part 44 1st connection part 46 1st Connection part 2 50 Photoelectric conversion layer 52 Electron blocking layer 100 Photoelectric conversion element 102 Substrate 104 First electrode 108 Second electrode 110 Sealing layer 112 Photoelectric conversion layer 114 Electron blocking layer

Claims (7)

A charge is generated according to received light formed between the first electrode, the second electrode formed above the first electrode, and the first electrode and the second electrode. A method for producing a photoelectric conversion element comprising: an organic layer having a photoelectric conversion layer; and a sealing layer for sealing the first electrode, the second electrode, and the organic layer,
An organic layer forming step of forming the organic layer above the first electrode; a second electrode forming step of forming the second electrode above the organic layer; and above the second electrode. A sealing layer forming step of forming the sealing layer,
Each step from the organic layer forming step to the sealing layer forming step is performed under vacuum,
Further, the method includes a step of placing a photoelectric conversion element intermediate in the process of non-vacuum with an irradiation light amount of 300 lux · h or less between the organic layer forming step and the second electrode forming step. A method for producing a photoelectric conversion element.   The manufacturing method of the photoelectric conversion element of Claim 1 which has a 1st electrode formation process which forms a said 1st electrode above a board | substrate before the said organic layer formation process.   The photoelectric conversion according to claim 1, wherein the organic layer forming step includes a step of forming an electron blocking layer on the first electrode and a step of forming the photoelectric conversion layer on the electron blocking layer. Device manufacturing method.   The method for producing a photoelectric conversion device according to any one of claims 1 to 3, wherein the non-vacuum placing step is performed with an irradiation light amount of 200 lux · h or less.   The said photoelectric conversion layer is a manufacturing method of the photoelectric conversion element of any one of Claims 1-4 which has a bulk heterostructure of a p-type organic semiconductor and an n-type organic semiconductor. The said p-type organic semiconductor is a manufacturing method of the photoelectric conversion element of Claim 5 containing the compound represented by General formula (1).
In the general formula (1), Z ₁ represents a ring containing at least two carbon atoms and represents a 5-membered ring, a 6-membered ring, or a condensed ring containing at least one of a 5-membered ring and a 6-membered ring. L ₁ , L ₂ , and L ₃ each independently represent an unsubstituted methine group or a substituted methine group. D ₁ represents an atomic group. n represents an integer of 0 or more.   The said n-type organic semiconductor is a manufacturing method of the photoelectric conversion element of Claim 5 or 6 containing a fullerene or a fullerene derivative.