JP2015074793A - Manufacturing method of photoelectric conversion layer and vapor deposition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a photoelectric conversion layer and a vapor deposition method in which a photoelectric conversion layer can be formed in a stable composition without deteriorating purity of an organic material and the like, and in which productivity is high.SOLUTION: In a manufacturing method of a photoelectric conversion layer, a photoelectric conversion layer is formed by depositing an organic material on a material to be deposited in a vapor deposition chamber in vacuum atmosphere. The method includes: a vapor deposition step of heating and evaporating the organic material and depositing the organic material on the material to be deposited; and a stop step of suppressing the evaporation of the organic material in a state where the heating of the organic material is maintained by supplying an inert gas to the vapor deposition chamber, and temporarily stopping the vapor deposition. In the stop step, when supply of the inert gas to the vapor deposition chamber is stopped, the evaporation of the organic material is resumed. Thus, the photoelectric conversion layer can be manufactured.

Description

  The present invention relates to a manufacturing method and a deposition method of a photoelectric conversion layer that can be used for manufacturing organic devices such as organic EL and organic CMOS, and in particular, a photoelectric conversion layer having a stable composition without deteriorating the purity of an organic material. It is related with the manufacturing method and vapor deposition method of a photoelectric converting layer which can form film.

In general, a vacuum heating deposition method is used to form the organic film. Applications of the organic film include, for example, applications for organic devices such as organic EL and organic CMOS. Various methods for producing an organic film have been proposed (Patent Documents 1, 2, etc.).
Patent Document 1 describes a method of forming an organic thin film on a substrate by introducing a very small amount of gas during vapor deposition, transporting an organic material sublimated by the gas flow to the substrate, and forming a film. .
Specifically, TPD (N, N′-diphenyl-N, N-bis (3-methylphenyl) 1,1′-biphenyl-4,4′diamine) vapor is transported to the substrate by using a carrier gas. The formation of a layer is described.

  In Patent Document 2, an organic thin film material disposed in an organic evaporation source is placed in an inert gas atmosphere, heated to a predetermined temperature, and a vapor of the organic thin film material is generated in a vacuum atmosphere to form an organic thin film. Yes. Further, in Patent Document 2, the start and end of vapor deposition are performed by changing the degree of vacuum based on the introduction of an inert gas (when the vapor deposition is started, the introduction of the inert gas is stopped and the degree of vacuum is raised to complete the vapor deposition. In some cases, the deposition is started or stopped only by the change in the degree of vacuum by introducing an inert gas to a pressure at which it does not evaporate).

JP-T-2001-523768 Japanese Patent Laid-Open No. 10-158820

When the vapor deposition method as in Patent Document 1 is used, in the mass production of an organic vapor deposition film, an organic material that is weak against heat is decomposed by continuous heating. It is continuously heated to prevent decomposition. However, it is necessary to lower the temperature of the material heating unit every time the material is supplied, and then raise the temperature to a temperature necessary for vapor deposition. As a result, the time during which vapor deposition cannot be increased increases the productivity.
On the other hand, in Patent Document 2, the start and end of vapor deposition are performed by changing the degree of vacuum based on the introduction of an inert gas. However, in Patent Document 2, when an organic film is deposited, the number of times of temperature rise and fall is large, it takes time for heating and temperature lowering, and energy required for heating is also required. For this reason, production cost increases and productivity is low.

  An object of the present invention is to solve the problems based on the above-described conventional technology, to form a photoelectric conversion layer with a stable composition without deteriorating the purity of the organic material, etc., and to have high productivity. It is providing the manufacturing method and vapor deposition method of these.

  In order to achieve the above object, a first aspect of the present invention is a manufacturing method for forming an organic film by depositing an organic material on a film forming material in a vacuum atmosphere deposition chamber. A vapor deposition process in which the organic material is heated and evaporated in the room to evaporate the organic material on the film deposition material, and the organic material is evaporated by supplying an inert gas into the vapor deposition room while maintaining the heating of the organic material. Resumes the process of stopping the deposition, temporarily stopping the deposition, and stopping the supply of the inert gas into the deposition chamber while maintaining the heating of the organic material to a vacuum atmosphere and restarting the deposition of the organic material And providing a method for producing a photoelectric conversion layer, characterized by having a supply step of supplying an organic material used for vapor deposition in a state where an inert gas is supplied into the vapor deposition chamber in the stop step. is there.

In the stop step, it is preferable to further include an exchange step of exchanging the film forming material in a state where an inert gas is supplied into the vapor deposition chamber.
For example, as the inert gas, any of nitrogen gas, helium gas, argon gas, neon gas, krypton gas, and xenon gas can be used.
The pressure in the vapor deposition chamber when the inert gas is introduced is preferably 1 × 10 ⁻² Pa to 10 Pa. Further, for example, the film forming material is a substrate on which a lower electrode is formed.

  According to a second aspect of the present invention, there is provided a vapor deposition method for depositing an organic material on a film forming material in a vacuum atmosphere deposition chamber to form an organic film, wherein the organic material is heated in the vacuum atmosphere deposition chamber. Evaporation process to evaporate the organic material on the film deposition material, and while maintaining the heating of the organic material, the inert gas is supplied into the deposition chamber to suppress the evaporation of the organic material, and the deposition is temporarily A stop process, and in a state where the heating of the organic material is maintained, the supply of the inert gas into the deposition chamber is stopped to form a vacuum atmosphere, and the restart process of restarting the deposition of the organic material. The present invention provides a vapor deposition method characterized by having a supply step of supplying an organic material used for vapor deposition in a state where an inert gas is supplied into the vapor deposition chamber.

  According to the present invention, by supplying an inert gas into the vapor deposition chamber, the evaporation of the organic material can be suppressed without lowering the temperature in the vapor deposition chamber, and the vapor deposition can be performed quickly by stopping the supply of the inert gas. Can resume. Thereby, the productivity of film formation of the photoelectric conversion layer and the organic film can be improved, and a significant cost reduction of the film formation of the photoelectric conversion layer and the organic film can be realized. Moreover, by suppressing the evaporation of the organic material without lowering the temperature in the vapor deposition chamber, it is possible to deposit with a stable composition without degrading the purity of the organic material, etc. An organic film can be obtained.

It is typical sectional drawing which shows an example of the vapor deposition apparatus of the organic material used for the manufacturing method of the organic film of embodiment of this invention. (A)-(d) is a schematic diagram which shows the manufacturing method of the organic film of embodiment of this invention in process order. It is a graph which shows the pressure and vapor deposition temperature in the vapor deposition chamber in the case of film-forming of an organic film. It is typical sectional drawing which shows an example of the photoelectric conversion element formed using the manufacturing method of the photoelectric converting layer of embodiment of this invention. (A)-(c) is typical sectional drawing which shows a part of manufacturing process of the photoelectric conversion element containing the manufacturing process of the photoelectric converting layer of embodiment of this invention in process order.

Below, based on suitable embodiment shown to an accompanying drawing, the manufacturing method and vapor deposition method of the photoelectric converting layer of this invention are demonstrated in detail.
FIG. 1 is a schematic cross-sectional view showing an example of an organic material vapor deposition apparatus used in an organic film manufacturing method according to an embodiment of the present invention.
An organic material vapor deposition apparatus 10 shown in FIG. 1 is used for forming an organic film such as an organic EL and an organic CMOS, for example, and deposits an organic material on a film formation material in a vacuum atmosphere. Is deposited. The film forming material is, for example, the substrate 100, and the organic film 102 is formed on the surface 100a. Note that the film formation material is not particularly limited, and a film formation material such as an organic EL or an organic CMOS can be used as the film formation material.
The organic film 102 is a photoelectric conversion layer such as an organic CMOS.

The vapor deposition apparatus 10 basically deposits a vapor deposition chamber 12, a vacuum exhaust unit 14 that reduces the pressure inside the vapor deposition chamber 12 to a predetermined vacuum level (pressure), and deposits an organic material on the film forming material. Deposition unit 16, gas supply unit 18 that supplies inert gas Gi to the interior 12 a of the deposition chamber 12, pressure sensor 19 that measures the pressure in the interior 12 a of the deposition chamber 12, and control that controls each unit of the deposition apparatus 10. Part 20. In the vapor deposition apparatus 10, even when the illustration is omitted, the control unit 20 is connected to each unit and is controlled by the control unit 20.
Although not shown, the vapor deposition apparatus 10 includes a substrate transport unit that carries the substrate 100 into and out of the interior 12 a of the vapor deposition chamber 12. The substrate transport unit (not shown) is also controlled by the control unit 20.

The vacuum exhaust unit 14 is connected to the vapor deposition chamber 12 via a pipe 15, and exhausts the interior 12 a of the vapor deposition chamber 12 to maintain a predetermined degree of vacuum (pressure). The inside 12a of the vapor deposition chamber 12 is brought to a pressure of about 1 × 10 ⁻⁵ Pa to 1 × 10 ⁻⁴ Pa during vapor deposition, for example, by the vacuum exhaust unit 14.
The vacuum exhaust unit 14 is controlled by the control unit 20. Moreover, the vacuum exhaust part 14 has various vacuum pumps generally used for a vapor deposition apparatus, and has vacuum pumps, such as a dry pump and a turbo-molecular pump.

  A pressure sensor 19 inside the vapor deposition chamber 12 is connected to the control unit 20. Based on the pressure obtained by the pressure sensor 19, the evacuation unit 14 is operated by the control unit 20 to a predetermined pressure. Further, the pressure when the inert gas Gi is supplied from the gas supply unit 18 to be described later to the inside 12 a of the vapor deposition chamber 12 is also measured by the pressure sensor 19, and the supply amount such as the flow rate of the inert gas Gi is controlled by the control unit 20. Be controlled.

The vapor deposition part 16 evaporates the organic material m, and vapor-deposits it on the surface 100a of the board | substrate 100 by applying the vapor | steam Vo.
The vapor deposition unit 16 includes a crucible 22, a heating unit 24, a power supply unit 26, and a material supply unit 28. The crucible 22 and the heating unit 24 are disposed inside the vapor deposition chamber 12, and the power source unit 26 is provided outside the vapor deposition chamber 12 and is connected to the control unit 20. The material supply unit 28 is provided outside the vapor deposition chamber 12, and enters the inside 22 a of the vapor deposition chamber 12 to supply the organic material m to the inside 22 a of the crucible 22 when supplying the material. The material supply unit 28 is also connected to the control unit 20.

The crucible 22 stores the organic material m in the interior 22a. The crucible 22 is heated to evaporate the organic material m, and vapor Vo is generated. The organic material m is in the form of, for example, a powder or a granule.
The heating unit 24 is for heating the crucible 22 and evaporating the organic material m. The configuration of the heating unit 24 is not particularly limited as long as the organic material m can be evaporated. For example, various heating methods such as a resistance heating method and an induction heating method can be used. If the heating unit 24 is an induction heating system, an induction heating coil is provided.
The power supply unit 26 supplies the heating unit 24 with a voltage or current corresponding to the heating method, and evaporates the organic material m. For example, if the heating unit 24 is an induction heating system, it has a high frequency power source connected to the induction heating coil.

The material supply unit 28 supplies the organic material m to the crucible 22 inside 22a. It is arranged outside the vapor deposition chamber 12 except when supplying the organic material m. The material supply unit 28 enters the interior 12a of the deposition chamber 12 and supplies the organic material m to the interior 22a of the crucible 22 while the inert gas Gi is supplied to the interior 12a of the deposition chamber 12 as will be described later. .
The configuration of the supply mechanism of the organic material m in the material supply unit 28 is not particularly limited as long as the organic material m can be supplied to the inside 22 a of the crucible 22.

The gas supply unit 18 supplies the inert gas Gi to the inside 12 a of the vapor deposition chamber 12. The gas supply unit 18 includes a gas supply source 30, a pipe 32, and an inert gas introduction valve 34 (hereinafter simply referred to as a valve 34).
The gas supply source 30 includes, for example, a gas cylinder (not shown) filled with an inert gas. A gas cylinder is a well-known thing and has general components provided in gas cylinders, such as a regulator.
As the inert gas, for example, any of nitrogen gas, helium gas, argon gas, neon gas, krypton gas, and xenon gas can be used.

When supplying the inert gas Gi to the inside 12a of the vapor deposition chamber 12, it is preferable that the pressure of the inside 12a is 1 * 10 ^<-2 > Pa ^- 10Pa. If the pressure in the interior 12a is less than 1 × 10 ⁻² Pa, the organic material m in the interior 22a of the crucible 22 may be heated unevenly, causing thermal decomposition or the like, and may not be deposited with a stable composition.
On the other hand, when the pressure in the interior 12 a exceeds 10 Pa, the evaporation of the organic material m is excessively suppressed, and the organic material m is further heated in the interior 22 a of the crucible 22. Thereby, there exists a possibility that it cannot vapor-deposit with a stable composition.

The gas supply source 30 is connected to the vapor deposition chamber 12 via a pipe 32, and the inert gas Gi is supplied from the gas supply source 30 to the interior 12 a of the vapor deposition chamber 12.
The pipe 32 is provided with a valve 34. The valve 34 can be opened and closed by an electrical signal, for example, and is connected to the control unit 20. Whether the inert gas Gi is supplied to the interior 12 a of the vapor deposition chamber 12 is controlled by opening and closing the valve 34 by the control unit 20.

Next, the manufacturing method of the organic film of this embodiment is demonstrated.
2A to 2D are schematic views showing the method of manufacturing the organic film according to the embodiment of the present invention in the order of steps. FIG. 3 is a graph showing the pressure in the vapor deposition chamber and the vapor deposition temperature when the organic film is formed. In addition, although the vapor deposition apparatus 10 of Fig.2 (a)-(d) has simplified and shown the structure, it has the structure similar to the vapor deposition apparatus 10 shown in FIG.

As shown in FIG. 2A, with the valve 34 closed, the inside 12a of the vapor deposition chamber 12 is set to a predetermined vacuum level, for example, a vapor deposition pressure of about 1 × 10 ⁻⁵ Pa to 1 × 10 ⁻⁴ Pa. After forming the vacuum atmosphere, the crucible 22 of the vapor deposition unit 16 is heated by the heating unit 24 to melt the organic material m, and the vapor Vo of the organic material m is blown toward the surface 100a of the substrate 100, so that the surface 100a The organic film 102 is formed on the surface 100a by vapor deposition (deposition process).
When the predetermined vapor deposition time has elapsed and the organic material m in the crucible 22 inside 22a has decreased, as shown in FIG. 2 (b), the control unit 20 opens the valve 34 to provide an inert gas such as N ₂ gas ( Nitrogen gas) is supplied to the inside 12 a of the vapor deposition chamber 12. At this time, N ₂ gas is supplied to the interior 12 a so that the pressure in the interior 12 a of the vapor deposition chamber 12 is 1 × 10 ⁻² Pa to 10 Pa. Thereby, discharge | release of the vapor | steam Vo from the crucible 22 is suppressed, and vapor deposition is stopped temporarily (stop process). That is, the film formation of the organic film 102 is temporarily stopped.

  In a state where vapor deposition is temporarily stopped, the organic material m is additionally supplied to the inside 22a of the crucible 22 as shown in FIG. At this time, if the organic film 102 is formed on the surface 100a of the substrate 100 as desired, the substrate 100 can be replaced (exchange process). The timing of replacing the substrate 100 is not particularly limited, and is determined as appropriate depending on the thickness of the organic film 102 to be formed, the size of the substrate 100, and the like. For example, it is not necessary to replace the substrate 100 even if the additional supply of the organic material m is performed a plurality of times.

Thereafter, as shown in FIG. 2D, the valve 34 is closed by the controller 34 to stop the supply of N ₂ gas. Thereby, the pressure of the inside 12a of the vapor deposition chamber 12 reaches the above-mentioned vapor deposition pressure, and becomes a vacuum atmosphere. As a result, the suppression of the evaporation of the organic material m is removed, the organic material m is evaporated from the crucible 22, the vapor Vo is released, and deposited on the surface 100a of the substrate 100, and the organic film 102 is formed on the surface 100a. (Resume process). In this way, the vapor deposition is resumed, and the film formation of the organic film 102 is resumed.

  In the organic film manufacturing method (deposition method of the organic material m) of the present embodiment, the execution of vapor deposition (deposition step) and the temporary stop of vapor deposition (stop step) are controlled by the presence or absence of the supply of inert gas. The deposition can be started immediately (resumption process). For example, as shown in FIG. 3, when the zone α is set as the time of vapor deposition and the zone β is set as the time when the vapor deposition is stopped, the vapor deposition can be repeatedly carried out in a cycle as indicated by the symbol A. The organic film 102 is repeatedly formed. For example, a predetermined organic film 102 can be formed on the substrate 100 for each section α, and the organic material m can be replenished and the substrate 100 can be replaced for each section β.

In the present embodiment, the vacuum chamber 14 reduces the pressure in the vapor deposition chamber to a vapor deposition pressure Pv of about 1 × 10 ⁻⁵ Pa to 1 × 10 ⁻⁴ Pa in the section α during vapor deposition. On the other hand, in the zone β when vapor deposition is stopped, the inert gas Gi is supplied to the inside 12a, and the pressure in the vapor deposition chamber is set to the pressure Ps during introduction of the inert gas of about 1 × 10 ⁻² Pa to 10 Pa.
As shown in FIG. 3, the pressure in the evaporation chamber ranges from a deposition pressure Pv (about 1 × 10 ⁻⁵ Pa to 1 × 10 ⁻⁴ Pa) to an inert gas introduction pressure Ps (about 1 × 10 ⁻² Pa to about 10 Pa). Fluctuates in range. However, it is sufficiently lower than atmospheric pressure (101.33 kPa) and does not open to the atmosphere. As described above, the supply of the organic material m and the exchange of the substrate 100 are performed in a relatively low pressure environment of about 1 × 10 ⁻² Pa to 10 Pa in the section β in a state where the inert gas Gi is supplied to the inside 12a.
In addition, in the method for producing an organic film (deposition method for the organic material m), the heating of the crucible 22 by the heating unit 24 is continued. As shown by reference symbol C, before the start of deposition, before the first section α. After reaching the vapor deposition temperature Tv, the controller 20 keeps the vapor deposition temperature Tv substantially constant regardless of whether the vapor deposition is in progress (section α) or during the temporary stop of vapor deposition (section β). In this way, the organic material m is constantly heated, and when the supply of the inert gas Gi to the inside 12a is stopped, the vapor deposition of the organic material m is promptly resumed, and the organic film is rapidly resumed. can do.

  In this embodiment, by introducing the inert gas Gi into the interior 12a of the vapor deposition chamber 12, the evaporation of the organic material m can be suppressed without lowering the temperature. Moreover, vapor deposition of the organic material m can be restarted quickly by stopping the introduction of the inert gas. Thereby, the productivity of organic film formation can be improved. Since vapor deposition can be performed at a substantially constant vapor deposition temperature, the temperature raising step and the temperature lowering step can be reduced as compared with the conventional case, and energy required for the temperature rise can be saved. For this reason, it is possible to realize a significant cost reduction in the formation of the organic film and to suppress the evaporation of the organic material m without lowering the temperature. The organic material m can be vapor-deposited with a stable composition without causing deterioration. For this reason, this embodiment is suitable for manufacturing an organic film composed of an organic material m that changes its composition in response to a temperature change. In addition, since the temperature of the material can be lowered without opening to the atmosphere, it can be suitably used for the organic material m that needs to be deposited little by little.

Hereinafter, the method for producing the photoelectric conversion layer of the present embodiment will be specifically described with a photoelectric conversion element as an example.
FIG. 4 is a schematic cross-sectional view illustrating an example of a photoelectric conversion element formed using the method for manufacturing a photoelectric conversion layer according to an embodiment of the present invention.

A photoelectric conversion element 50 shown in FIG. 4 converts a visible light image into an electric signal, and is formed on an insulating layer 54 formed on a substrate 52.
The photoelectric conversion element 50 includes a pixel electrode (lower electrode) 56, an organic layer 58, a counter electrode (upper electrode) 60, a protective film (sealing layer) 62, a color filter 64, a partition wall 66, and a light shielding layer. 68 and an overcoat layer 70.

A reading circuit 80 and a counter electrode voltage supply unit 82 are formed on the substrate 52. As the substrate 52, for example, a glass substrate or a semiconductor substrate such as Si is used.
A plurality of pixel electrodes 56 are formed on the surface of the insulating layer 54. The pixel electrodes 56 are arranged in a one-dimensional or two-dimensional manner, for example.
In addition, a first connection portion 84 that connects the pixel electrode 56 and the readout circuit 80 is formed in the insulating layer 54. Furthermore, a second connection portion 86 for connecting the counter electrode 60 and the counter electrode voltage supply unit 82 is formed. The second connection part 86 is formed at a position not connected to the pixel electrode 56 and the organic layer 58. The 1st connection part 84 and the 2nd connection part 86 are formed with the electroconductive material.

  A wiring layer 88 made of a conductive material for connecting the readout circuit 80 and the counter electrode voltage supply unit 82 to, for example, the outside of the photoelectric conversion element 50 is formed inside the insulating layer 54. As described above, the insulating layer 54 formed on the substrate 52 is collectively referred to as a circuit board 51. The circuit board 51 is also referred to as a CMOS substrate.

An organic layer 58 is formed so as to cover the plurality of pixel electrodes 56 and to avoid the second connection portion 86. The organic layer 58 has an electron blocking layer 72 and a photoelectric conversion layer 74.
In the organic layer 58, the electron blocking layer 72 is formed on the pixel electrode 56 side, and the photoelectric conversion layer 74 is formed on the electron blocking layer 72.
The electron blocking layer 72 is a layer for suppressing injection of electrons from the pixel electrode 56 to the photoelectric conversion layer 74.
The photoelectric conversion layer 74 generates an electric charge according to the amount of received light such as incident light L (visible light), and includes an organic photoelectric conversion material.

The counter electrode 60 is an electrode facing the pixel electrode 56 and is provided so as to cover the photoelectric conversion layer 74. A photoelectric conversion layer 74 is provided between the pixel electrode 56 and the counter electrode 60.
The counter electrode 60 is made of a conductive material that is transparent to the incident light L (visible light) in order to make light incident on the photoelectric conversion layer 74. The counter electrode 60 is electrically connected to the second connection portion 86 disposed outside the photoelectric conversion layer 74, and is connected to the counter electrode voltage supply portion 82 via the second connection portion 86. Yes.

  The counter electrode voltage supply unit 82 applies a predetermined voltage to the counter electrode 60 via the second connection unit 86. When the voltage to be applied to the counter electrode 60 is higher than the power supply voltage of the photoelectric conversion element 50, the power supply voltage is boosted by a booster circuit such as a charge pump to supply the predetermined voltage.

  The pixel electrode 56 is an electrode for collecting charges for collecting charges generated in the organic layer 58 (photoelectric conversion layer 74). The pixel electrode 56 is connected to the readout circuit 80 via the first connection portion 84. The readout circuit 80 is provided on the substrate 52 corresponding to each of the plurality of pixel electrodes 56, and reads out a signal corresponding to the charge collected by the corresponding pixel electrode 56.

The readout circuit 80 is constituted by, for example, a CCD, a MOS circuit, a TFT circuit, or the like, and is shielded from light by a light shielding layer (not shown) provided in the insulating layer 54.
Although not shown, for example, a high-concentration n region surrounded by a p region is formed on the substrate 52, and the first connection portion 84 is connected to the n region. A read circuit 80 is provided in the p region. The n region functions as a charge storage unit that stores the charge of the photoelectric conversion layer 74. The signal charge accumulated in the n region is converted into a signal corresponding to the amount of charge by the readout circuit 80 and is output to the outside of the photoelectric conversion element 50 through the wiring layer 88, for example.

  The protective film 62 is for protecting the organic layer 58 including the photoelectric conversion layer 74 from deterioration factors such as water molecules and oxygen. The protective film 62 is formed so as to cover the counter electrode 60, and is formed of, for example, a silicon oxynitride film (SiON film). Further, the incident light L (visible light) reaches the organic layer 58 through the protective film 62. For this reason, the protective film 62 is transparent to light having a wavelength detected by the organic layer 58, for example, incident light L (visible light).

  The color filter 64 is formed at a position facing each pixel electrode 56 on the protective film 62. The partition 66 is provided between the color filters 64 on the protective film 62 and is for improving the light transmission efficiency of the color filter 64. The light shielding layer 68 is formed in a region other than the region (effective pixel region) in which the color filter 64 and the partition wall 66 are provided on the protective film 62, and light is incident on the photoelectric conversion layer 74 formed outside the effective pixel region. Is to prevent. The color filter 64, the partition 66, and the light shielding layer 68 are formed by, for example, a photolithography method.

The overcoat layer 70 is for protecting the color filter 64 from subsequent processes and is formed so as to cover the color filter 64, the partition wall 66 and the light shielding layer 68.
In the photoelectric conversion element 50, one pixel electrode 56 with the organic layer 58, the counter electrode 60, and the color filter 64 provided thereon is a unit pixel.

  As the overcoat layer 70, a known layer used for an organic solid-state imaging device is used. For the overcoat layer 70, a polymer material such as an acrylic resin, a polysiloxane resin, a polystyrene resin, and a fluorine resin, or an inorganic material such as silicon oxide and silicon nitride can be used as appropriate. The overcoat layer 70 may be formed in a predetermined vacuum or non-vacuum. The overcoat layer 70 can also be used 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 64.

Examples of the material of the pixel electrode 56 include metals, metal oxides, metal nitrides, metal borides, organic conductive compounds, and mixtures thereof. Specific examples include conductive metal oxides such as tin oxide (SnO ₂ ), zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), indium tungsten oxide (IWO), and titanium oxide, and nitride Metal nitrides such as titanium (TiN), gold (Au), platinum (Pt), silver (Ag), chromium (Cr), nickel (Ni), aluminum (Al), and other metals, and conductivity with these metals Examples thereof include mixtures or laminates with metal oxides, organic conductive compounds such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO. The material of the pixel electrode 56 is particularly preferably any of titanium nitride, molybdenum nitride, tantalum nitride, and tungsten nitride. A particularly preferable material among the materials of the pixel electrode 56 is TiN.

  A step corresponding to the film thickness of the pixel electrode 56 is steep at the end of the pixel electrode 56, a significant unevenness exists on the surface of the pixel electrode 56, or minute dust (particles) adheres to the pixel electrode 56. As a result, the layer on the pixel electrode 56 becomes thinner than a desired film thickness or cracks occur. When the counter electrode 60 is formed on the layer in such a state, a pixel defect such as an increase in dark current or a short circuit occurs due to contact or electric field concentration between the pixel electrode 56 and the counter electrode 60 in the defective portion. Further, the above-described defects may reduce the adhesion between the pixel electrode 56 and the layer above it or the heat resistance of the photoelectric conversion element 50.

  In order to prevent the above defects and improve the reliability of the element, the surface roughness Ra (arithmetic average roughness) of the pixel electrode 56 is preferably 0.6 nm or less. The smaller the surface roughness Ra of the pixel electrode 56 is, the smaller the surface unevenness is, and the surface flatness is better. In order to remove particles on the pixel electrode 56, it is particularly preferable to clean the pixel electrode 56 and the like using a general cleaning technique used in a semiconductor manufacturing process before the electron blocking layer 72 is formed. preferable.

Examples of the material of the counter electrode 60 include metals, metal oxides, metal nitrides, metal borides, organic conductive compounds, and mixtures thereof. Specific examples include tin oxide (SnO ₂ ), zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), indium tungsten oxide (IWO), conductive metal oxides such as titanium oxide, TiN Metal nitrides such as gold (Au), platinum (Pt), silver (Ag), chromium (Cr), nickel (Ni), aluminum (Al), etc., and these metals and conductive metal oxides A mixture or laminate of the above, an organic conductive compound such as polyaniline, polythiophene, and polypyrrole, a laminate of these with ITO, and the like. Particularly preferable materials for the transparent conductive film are ITO, IZO, tin oxide (SnO ₂ ), antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), zinc oxide, antimony-doped zinc oxide (AZO), gallium. Any material of doped zinc oxide (GZO). A particularly preferable material among the materials of the counter electrode 60 is ITO.

  An electron donating organic material can be used for the electron blocking layer 72. 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 electron blocking layer 72 is preferably made of a material having a high electron injection barrier from the adjacent pixel electrode 56 and a high hole transporting property. As an electron injection barrier, the electron affinity of the electron blocking layer 72 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 72 preferably has a thickness of 20 nm or more in order to sufficiently suppress the contact between the pixel electrode 56 and the photoelectric conversion layer 74 and to avoid the influence of defects and dust existing on the surface of the pixel electrode 56. More preferably, it is 40 nm or more, and particularly preferably 60 nm or more.
On the other hand, if the thickness of the electron blocking layer 72 is too large, a problem arises in that the supply voltage necessary for applying an appropriate electric field strength to the photoelectric conversion layer 74 increases, and the carrier transport process in the electron blocking layer 72 occurs. However, there is a problem that the performance of the photoelectric conversion element is adversely affected. The thickness of the electron blocking layer 72 is preferably 300 nm or less, more preferably 200 nm or less, and still more preferably 100 nm or less.

  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 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.

  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 56 or the counter electrode 20 via the fullerene molecule or the 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 74, 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 74 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 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, said A-1 to A-12, B-1 to B-9, and C-1 to C-16 are synonymous with what was shown to the said 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. In addition, the following compound 2, the following compound 4, the following compound 5, and the following compound 6 are mentioned.

(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.

  Note that the photoelectric conversion element 50 shown in FIG. 4, the substrate 52, and the insulating layer 54 constitute an imaging element. The image pickup device is used by being mounted on an image pickup device such as a digital camera or a digital video camera, an image pickup module such as an electronic endoscope or a mobile phone.

Next, a method for manufacturing the photoelectric conversion layer 74 of the photoelectric conversion element 50 illustrated in FIG. 4 will be described together with a method for manufacturing the photoelectric conversion element 50.
First, as shown in FIG. 5A, a first connection portion 84, a second connection portion 86, and a wiring layer 88 are formed on a substrate 52 on which a readout circuit 80 and a counter electrode voltage supply portion 82 are formed. A circuit board 51 (CMOS substrate) on which an insulating layer 54 provided with is formed is prepared. Then, the pixel electrode 56 is formed on the surface 54 a of the insulating layer 54 so as to be connected to each first connection portion 84. In this case, as described above, the first connection portion 84 and the readout circuit 80 are connected, and the second connection portion 86 and the counter electrode voltage supply portion 82 are connected. The circuit substrate 51 on which the pixel electrode 56 is formed corresponds to the substrate of the present invention.

  Next, using the vapor deposition apparatus 10, as shown in FIG. 5B, an electron blocking material is vapor deposited so as to cover all the pixel electrodes 56 except for the second connection portion 86, and the electron blocking is performed. Layer 72 is formed. As the electron blocking material, an organic material constituting the electron blocking layer 72 described above can be used. More specifically, for example, the following compound 1 in powder form can be used as the electron blocking material.

Next, as illustrated in FIG. 5C, a photoelectric conversion material is vapor-deposited on the surface 72 a of the electron blocking layer 72 using the vapor deposition apparatus 10, thereby forming a photoelectric conversion layer 74. Thereby, the photoelectric conversion layer 74 is formed and the organic layer 58 is formed.
As the photoelectric conversion material (organic material), a p-type organic semiconductor constituting the photoelectric conversion layer 74 described above can be used. More specifically, for example, the following compound 2 (p-type organic semiconductor) in powder form and the following compound 3 (n-type organic semiconductor) in powder form can be used as the photoelectric conversion material. The photoelectric conversion layer 74 is formed by using the organic film manufacturing method shown in FIGS. For this reason, the detailed description is abbreviate | omitted.

  Next, the counter electrode 60 is formed under a predetermined vacuum using, for example, a sputtering method in a pattern that covers the organic layer 58 and is formed on the second connection portion 86. Next, a protective film 62 is formed on the surface 54 a of the insulating layer 54 so as to cover the counter electrode 60.

Next, the color filter 64, the partition 66, and the light shielding layer 68 are formed on the surface 62a of the protective film 62 by using, for example, a photolithography method. The formation process of the color filter 64, the partition 66, and the light shielding layer 68 may be under a predetermined vacuum or non-vacuum.
Next, the overcoat layer 130 is formed using, for example, a coating method so as to cover the color filter 64, the partition 66, and the light shielding layer 68. Thereby, the photoelectric conversion element 50 shown in FIG. 4 can be formed.

  In the present embodiment, when the photoelectric conversion element 50 is manufactured, the photoelectric conversion layer 74 is formed by forming the photoelectric conversion layer 74 using the method for manufacturing an organic film shown in FIGS. The photoelectric conversion layer 74 can be formed with a stable composition without causing deterioration of the purity or the like associated with the temperature change of the organic material used for the film formation. For this reason, the photoelectric conversion layer 74 can be comprised with a highly purified film | membrane.

Even when the photoelectric conversion layer 74 is repeatedly formed in the vapor deposition chamber 12, the photoelectric conversion material (organic material) is introduced without lowering the vapor deposition temperature by introducing the inert gas Gi into the inside 12 a of the vapor deposition chamber 12. The evaporation can be temporarily stopped and the evaporation can be temporarily stopped. At this time, a photoelectric conversion material (organic material) can be additionally supplied. At this time, if film formation of the photoelectric conversion layer 74 is completed, the substrate on which the film formation of the photoelectric conversion layer 74 has been completed is carried out, and a substrate before the film formation of the photoelectric conversion layer 74 is newly carried in. You can also.
Even in this case, since the deposition of the photoelectric conversion material (organic material) can be controlled by the presence or absence of the supply of the inert gas as described above, the temperature rise and the temperature fall can be omitted, and the atmosphere is not released to the atmosphere. For this reason, since the time required for manufacturing the photoelectric conversion layer 74 can be shortened and the heating energy required for manufacturing the photoelectric conversion layer 74 can be reduced, the productivity of the photoelectric conversion layer 74 and, consequently, the productivity of the photoelectric conversion element can be improved. And the cost of the photoelectric conversion element can be greatly reduced.

  In addition, the structure of the photoelectric conversion element 50 is not limited to the structure shown in FIG. For example, the structure may be a pixel electrode (lower electrode) / electron blocking layer / photoelectric conversion layer / upper electrode / protective film in this order from the surface side of the substrate. In this case, the protective film may have a single layer structure or a multilayer structure of two or more layers.

  The present invention is basically configured as described above. As mentioned above, although the manufacturing method and vapor deposition method of the photoelectric converting layer of this invention were demonstrated in detail, this invention is not limited to the said embodiment, In the range which does not deviate from the main point of this invention, various improvement or a change is carried out. Of course it is also good.

Hereinafter, the effect of the manufacturing method of the photoelectric converting layer of this invention is demonstrated concretely.
In this example, photoelectric conversion elements of Examples 1 to 4 and Comparative Example 1 were produced. About Examples 1-4, the photoelectric converting layer was produced with the manufacturing process shown in the following Table 1, and about the comparative example 1, the photoelectric converting layer was produced with the manufacturing process shown in the following Table 2.
About the photoelectric conversion element of Examples 1-4, seven levels were produced, changing the pressure in the vapor deposition chamber at the time of inert gas introduction, respectively. Four photoelectric conversion elements were produced for each level. An afterimage was measured for each photoelectric conversion element. Afterimage was evaluated. The results are shown in Tables 3-6 below.
In addition, the structure of a photoelectric conversion element is a structure of the protective film of the pixel electrode / electron blocking layer / photoelectric conversion layer / upper electrode / 2 layer structure formed on the substrate.

  For afterimages, the four photoelectric conversion elements of each level were each irradiated with 500 lux / F4 of light by shutter opening / closing operations every second, and the output signal immediately after the shutter was released (1/60 seconds) is the shutter. The percentage of the output signal when opened was measured. The 10 times average was evaluated as an afterimage of each photoelectric conversion element. Further, for each level, an average value of the four photoelectric conversion elements was calculated and used as a final afterimage value. The allowable value of the afterimage was set to 1.0%, the lower value was set as “EXCELLENT”, and the case where the afterimage value was larger than that was determined as “GOOD”.

Hereinafter, the photoelectric conversion elements of Examples 1 to 4 and Comparative Example 1 will be described.
(Example 1)
In Example 1, first, ITO was formed with a film thickness of 30 nm on a glass substrate by high frequency magnetron sputtering to form a pixel electrode. Next, on the pixel electrode, an organic compound represented by the following compound 1 was formed as an electron blocking layer with a film thickness of 100 nm by a vacuum deposition method.
On the electron blocking layer, as a photoelectric conversion layer, a mixed layer (compound) of an organic compound (p-type organic semiconductor) represented by the following compound 2 and an organic compound (fullerene C ₆₀ (n-type organic semiconductor)) represented by the following compound 3 2: Compound 3 = 1: 1 (volume ratio)) was formed by vacuum evaporation in a vacuum with a film thickness of 400 nm. In this case, the organic compound represented by the following compound 2 and the organic compound represented by the following compound 3 are housed in separate crucibles and deposited.
The vapor deposition of the organic compounds was performed under film forming conditions in which the degree of vacuum was 5.0 × 10 ⁻⁴ Pa or less and the vapor deposition rate was 1 Å / s to 10 Å / s.

On the photoelectric conversion layer, ITO was formed as a top electrode with a film thickness of 10 nm by high frequency magnetron sputtering. Next, a protective film was formed so as to cover the upper electrode. The protective film is a laminated film having a two-layer structure of an aluminum oxide film and a silicon nitride film. The aluminum oxide film was formed with a film thickness of 200 nm using an atomic layer deposition apparatus. The silicon nitride film was formed with a film thickness of 100 nm by magnetron sputtering.
In this example, the photoelectric conversion element was manufactured four times under the same conditions. At that time, the compound 2 is continuously vapor-deposited while supplying an organic material every two hours using the material supply unit while maintaining the pressure state in which the inert gas is introduced. The device was manufactured once, and the device was manufactured four times in a manufacturing process of about 10 hours in total. At this time, nitrogen gas having a purity of 99.9999% was used as the inert gas, and the pressure in the deposition chamber was adjusted to about 1 Pa. Details of the manufacturing process of Example 1 are shown in Table 1 below.

In Example 1, the pressure in the vapor deposition chamber at the time of gas introduction was set to about 1 × 10 ⁻³ Pa, about 1 × 10 ⁻² Pa, about 1 in addition to the pressure in the vapor deposition chamber at the time of introducing the inert gas being about 1 Pa. Photoelectric conversion elements were produced by changing the six levels of × 10 ⁻¹ Pa, about 1 × 10 ¹ Pa, about 1 × 10 ² Pa, and about 1 × 10 ³ Pa. In Example 1, four photoelectric conversion elements were manufactured for a total of seven levels. And the average value of the afterimage of the photoelectric conversion element was computed for every level.

(Example 2)
Example 2 has the same element configuration as that of Example 1, and a photoelectric conversion element was produced in the same manner as Example 1 except that Compound 2 was changed to Compound 4. For this reason, detailed description is omitted.
Also in Example 2, a total of 7 levels and 4 photoelectric conversion elements were produced by changing the pressure in the vapor deposition chamber when introducing the inert gas.

(Example 3)
Example 3 has the same element configuration as that of Example 1, and a photoelectric conversion element was produced in the same manner as Example 1 except that Compound 2 was changed to Compound 5. For this reason, detailed description is omitted.
Also in Example 3, a total of 7 levels and 4 photoelectric conversion elements were produced by changing the pressure in the vapor deposition chamber when introducing the inert gas.

Example 4
Example 4 has the same element configuration as that of Example 1, and a photoelectric conversion element was produced in the same manner as Example 1 except that Compound 2 was changed to Compound 6. For this reason, detailed description is omitted.
Also in Example 4, a total of 7 levels and 4 photoelectric conversion elements were produced by changing the pressure in the vapor deposition chamber when introducing the inert gas.

(Comparative Example 1)
Comparative Example 1 has the same element configuration as that of Example 1, and as shown in Table 2 below, a photoelectric conversion element was prepared in the same manner as in Example 1 except that it was manufactured by a manufacturing process in which an inert gas was not introduced into the vapor deposition chamber. Was made. For this reason, detailed description is omitted.
Also in the comparative example 1, the photoelectric conversion element was produced 4 times on the same conditions. However, since no gas is introduced into the vapor deposition chamber, only one level of photoelectric conversion element is manufactured.

  When Example 1 shown in Table 1 and Comparative Example 1 shown in Table 2 are compared, when an element is manufactured in a manufacturing process in which an inert gas is not introduced, the material does not evaporate before supplying the material. It is necessary to wait until the temperature (170 ° C.) is lowered, and the temperature must be raised again after supplying the material. In Comparative Example 1, it takes as long as 14 hours to produce the same element as in Example 1. On the other hand, in Example 1 in which an inert gas was introduced, the device production time was 9.8 hours. In Comparative Example 1, a time loss of about 40% occurs as compared with Example 1, and the mass production cost increases significantly.

As shown in Tables 3 to 6, when the pressure when introducing the inert gas is 10 ⁻² Pa to 10 ¹ Pa, the afterimage value (element performance) is remarkably high at 1% or less. The present invention is particularly effective when mass-producing organic devices such as organic EL and organic CMOS using an organic material that decomposes when deposited for a long time.

DESCRIPTION OF SYMBOLS 10 Deposition apparatus 12 Deposition chamber 14 Vacuum exhaust part 16 Evaporation part 18 Gas supply part 19 Pressure sensor 20 Control part 22 Crucible 28 Material supply part 30 Gas supply source 34 Inert gas introduction valve (valve)
50 photoelectric conversion element 58 organic layer 102 organic film

Claims (6)

A manufacturing method for forming a photoelectric conversion layer by depositing an organic material on a film forming material in a vacuum deposition chamber,
A vapor deposition step of heating and evaporating the organic material in the vapor deposition chamber in the vacuum atmosphere to deposit the organic material on the film formation material;
In a state where heating of the organic material is maintained, an inert gas is supplied into the vapor deposition chamber to suppress evaporation of the organic material, and a stop step of temporarily stopping the vapor deposition,
With the heating of the organic material maintained, the supply of the inert gas into the vapor deposition chamber is stopped and the vacuum atmosphere is resumed, and a resuming step of restarting the vapor deposition of the organic material,
The method for producing a photoelectric conversion layer, characterized in that, in the stopping step, the organic material used for the vapor deposition is supplied in a state where the inert gas is supplied into the vapor deposition chamber.   The method for producing a photoelectric conversion layer according to claim 1, further comprising an exchange step of exchanging the film forming material in a state where the inert gas is supplied into the vapor deposition chamber in the stopping step.   The method for producing a photoelectric conversion layer according to claim 1, wherein the inert gas is any one of nitrogen gas, helium gas, argon gas, neon gas, krypton gas, and xenon gas. The method for producing a photoelectric conversion layer according to any one of claims 1 to 3, wherein the pressure in the deposition chamber when the inert gas is introduced into the deposition chamber is 1 × 10 ^-2 Pa to 10 Pa.   The method for producing a photoelectric conversion layer according to claim 1, wherein the film forming material is a substrate on which a lower electrode is formed. An evaporation method for forming an organic film by depositing an organic material on a film forming material in a vacuum deposition chamber,
A vapor deposition step of heating and evaporating the organic material in the vapor deposition chamber in the vacuum atmosphere to deposit the organic material on the film formation material;
In a state where heating of the organic material is maintained, an inert gas is supplied into the vapor deposition chamber to suppress evaporation of the organic material, and a stop step of temporarily stopping the vapor deposition,
With the heating of the organic material maintained, the supply of the inert gas into the vapor deposition chamber is stopped and the vacuum atmosphere is resumed, and a resuming step of restarting the vapor deposition of the organic material,
The vapor deposition method characterized in that, in the stopping step, the organic material used for the vapor deposition is supplied in a state where the inert gas is supplied into the vapor deposition chamber.