Image pickup element and image pickup device

Abstract

An image pickup element according to an embodiment of the present disclosure includes: a first electrode; a second electrode disposed opposite to the first electrode; and an organic layer provided between the first electrode and the second electrode. The organic layer includes a compound represented by general formula (1).

Description

Technical Field

[0001] The present disclosure relates to an image pickup element in which an organic material is used and an image pickup apparatus including the image pickup element. Background Art

[0002] For example, Patent Document 1 discloses a photoelectric conversion element having an organic layer containing a compound represented by the following general formula (2): R1 and R4 of the compound represented by general formula (2) are alkyl groups such as methyl group.

[0003] [Chemical formula 1]

[0004]

[0005] Citation list

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. WO 2015 / 119039 Summary of the invention

[0008] Incidentally, an image pickup element in which an organic material is used is required to improve spectral characteristics.

[0009] It is desirable to provide an image pickup element and an image pickup device each of which can improve spectral characteristics.

[0010] The imaging element according to the embodiment of the present disclosure includes: a first electrode; a second electrode arranged to be opposite to the first electrode; and an organic layer provided between the first electrode and the second electrode. The organic layer includes a compound represented by the following general formula (1):

[0011] [Chemical formula 2]

[0012]

[0013] (Wherein, R1 and R4 each independently represent a hydrogen atom or a deuterium atom; R2 and R3 each independently represent an alkyl group, a cycloalkyl group, an alkoxy group or an aryl ether group; R5 and R6 each independently represent a halogen atom, a hydrogen atom or an alkyl group; R7 represents an aryl group, a heteroaryl group or an alkenyl group; M represents boron or an m-valent metal atom, and includes at least one of germanium, beryllium, magnesium, aluminum, chromium, iron, nickel, copper, zinc and platinum; L represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group; n represents an integer of 1 or more and 6 or less, and when n-1 is 2 or more, L each independently represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group.)

[0014] An image pickup device according to an embodiment of the present disclosure includes pixels each including one or more organic photoelectric conversion portions, and includes the above-described image pickup element according to an embodiment of the present disclosure as each of the organic photoelectric conversion portions.

[0015] In the imaging element according to the embodiment of the present disclosure and the imaging device according to the embodiment, the organic layer is formed using the compound represented by the above general formula (1). Therefore, the selectivity of the wavelength detected by the organic layer is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : is a schematic cross-sectional view showing an example of a configuration of an image pickup element according to a first embodiment of the present disclosure.

[0017] Figure 2 It shows Figure 1 The diagram shows the overall structure of the imaging element.

[0018] Figure 3 yes Figure 1 The equivalent circuit diagram of the imaging element shown.

[0019] Figure 4 It shows Figure 1 Schematic diagram of the arrangement of the lower electrode of the imaging element and the transistors constituting the control unit shown.

[0020] Figure 5 is a schematic cross-sectional view showing another example of the configuration of the image pickup element according to the first embodiment of the present disclosure.

[0021] Figure 6 It is used to illustrate Figure 1 A cross-sectional view showing a method for manufacturing an imaging element shown.

[0022] Figure 7 It shows that Figure 6 Cross-sectional view of the following steps.

[0023] Figure 8 It shows that Figure 7 Cross-sectional view of the following steps.

[0024] Fig. 9 It shows that Figure 8 Cross-sectional view of the following steps.

[0025] Fig.10 It shows that Fig. 9 Cross-sectional view of the following steps.

[0026] Fig.11 It shows Figure 1 A timing chart showing an example of the operation of the imaging element shown.

[0027] Fig.12 : is a schematic cross-sectional view showing an example of a configuration of an image pickup element according to a second embodiment of the present disclosure.

[0028] Fig.13 : is a schematic cross-sectional view showing an example of a configuration of an image pickup element according to a third embodiment of the present disclosure.

[0029] Fig.14 It shows that Figure 1 The imaging element shown in FIG. 1 is a block diagram of the structure of an imaging device in which pixels are used.

[0030] Fig.15 is shown where the use Fig.14 The functional block diagram of an example of an electronic device (camera) of an imaging device shown.

[0031] Fig.16 is a block diagram showing an example of a schematic configuration of an in-vivo information acquisition system.

[0032] Fig.17 is a view showing an example of a schematic configuration of an endoscopic surgery system.

[0033] Fig.18 : is a block diagram showing an example of the functional configuration of a camera head and a camera control unit (CCU: camera control unit).

[0034] Fig.19 is a block diagram showing an example of a schematic configuration of a vehicle control system.

[0035] Fig. 20 It is a diagram for assisting in explaining an example of the installation positions of the vehicle exterior information detection unit and the camera unit.

[0036] Fig.21 : is a characteristic diagram showing the absorption spectrum obtained by quantum science calculation of the compound (BODIPY dye) represented by formula (1-5).

[0037] Fig. 22 : is a characteristic diagram showing the absorption spectrum obtained by quantum science calculation of the compound (BODIPY dye) represented by formula (2-1).

[0038] Fig.23 : is a characteristic diagram showing the absorption spectrum obtained by quantum science calculation of the compound (BODIPY dye) represented by formula (2-2).

[0039] Fig.24 : is a characteristic diagram showing the absorption spectrum obtained by quantum science calculation of the compound (BODIPY dye) represented by formula (1-2).

[0040] Fig.25 : is a characteristic diagram showing the absorption spectrum obtained by quantum science calculation of the compound (BODIPY dye) represented by formula (1-3).

[0041] Fig.26 : is a characteristic diagram showing the absorption spectrum obtained by quantum science calculation of the compound (BODIPY dye) represented by formula (1-4).

[0042] Fig. 27 : is a characteristic diagram showing the absorption spectrum obtained by quantum science calculation of the compound (BODIPY dye) represented by formula (2-3).

[0043] Fig.28 It is a characteristic diagram showing the absorption spectra of the compounds (BODIPY dye) represented by Formula (1-5), Formula (2-1), and Formula (2-2). DETAILED DESCRIPTION

[0044] The following describes the embodiments of the present disclosure in detail with reference to the accompanying drawings. The following description is a specific example of the present disclosure, but the present disclosure is not limited to the following manner. In addition, the present disclosure is not limited to the arrangement, size, and size ratio of each component shown in each figure. It should be noted that the description is given in the following order.

[0045] 1. First Implementation Method

[0046] (Example of an imaging element having an organic photoelectric conversion unit including an organic layer containing a BODIPY compound having hydrogen atoms at the first and seventh positions)

[0047] 1-1. Structure of the imaging element

[0048] 1-2. Method for manufacturing imaging element

[0049] 1-3. Actions and effects

[0050] 2. Second Embodiment (Example in which two organic photoelectric conversion sections are stacked on a semiconductor substrate)

[0051] 3. Third Embodiment (Example in which three organic photoelectric conversion sections are stacked on a semiconductor substrate)

[0052] 4. Application examples

[0053] 5. Application examples

[0054] 6. Examples

[0055] <1. First Implementation Method>

[0056] Figure 1An example of a cross-sectional configuration of the image pickup element (image pickup element 10A) according to the first embodiment of the present disclosure is shown. Figure 2 Shows Figure 1 The planar structure of the imaging element 10A shown. Figure 3 yes Figure 1 An equivalent circuit diagram of the image pickup element 10A is shown. Figure 3 Corresponds to Figure 2 Area 100 is shown. Figure 4 Schematically shows Figure 1 The arrangement of the lower electrode 21 of the imaging element 10A and the transistor constituting the control unit is shown. For example, the imaging element 10A constitutes an imaging device such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in electronic devices such as digital cameras or video cameras (imaging device 1; see Fig.17 ) is a pixel (unit pixel P). The imaging element 10A according to the present embodiment includes an organic photoelectric conversion unit 20 in which a lower electrode 21, a photoelectric conversion layer 24, and an upper electrode 25 are stacked in this order. The photoelectric conversion layer 24 detects any one of the wavelength bands in the infrared region and the visible light region. The photoelectric conversion layer 24 is formed by using a compound represented by the following general formula (1). This photoelectric conversion layer 24 corresponds to a specific example of the “organic layer” according to the present disclosure.

[0057] (1-1. Structure of Image Pickup Element)

[0058] For example, the imaging element 10A is a so-called vertical splitting imaging element, in which one organic photoelectric conversion unit 20 and two inorganic photoelectric conversion units 32B and 32R are stacked in the vertical direction. The organic photoelectric conversion unit 20 is arranged on the first surface (back side; surface 30S1) side of the semiconductor substrate 30. The inorganic photoelectric conversion units 32B and 32R are formed to be buried in the semiconductor substrate 30 and stacked in the thickness direction of the semiconductor substrate 30. The organic photoelectric conversion unit 20 includes a photoelectric conversion layer 24 as described above as an organic layer formed using an organic material, and the photoelectric conversion layer 24 is located between the lower electrode 21 and the upper electrode 25. The lower electrode 21 and the upper electrode 25 are arranged relative to each other. The photoelectric conversion layer 24 includes a p-type semiconductor and an n-type semiconductor, and has a bulk heterojunction structure in the layer. The bulk heterostructure is a p / n junction formed by mixing a p-type semiconductor and an n-type semiconductor.

[0059] The organic photoelectric conversion unit 20 and the inorganic photoelectric conversion units 32B and 32R perform photoelectric conversion by selectively detecting each wavelength (each light) of a different wavelength band from each other. For example, the organic photoelectric conversion unit 20 absorbs wavelengths of the green wavelength band and obtains a green (G) color signal. The inorganic photoelectric conversion units 32B and 32R absorb wavelengths of the blue wavelength band to obtain a blue (B) color signal and absorb wavelengths of the red wavelength band to obtain a red (R) color signal due to different absorption coefficients. This allows the imaging element 10A to obtain multiple color signals in one pixel without using a color filter.

[0060] It should be noted that in this embodiment, the case where the electron in a pair of electrons and holes (electron-hole pairs) generated by photoelectric conversion is read out as a signal charge (the case where the n-type semiconductor region is used as a photoelectric conversion layer) is described. In addition, in the drawings, "+ (plus sign)" attached to "p" or "n" indicates that the concentration of p-type or n-type impurities is high.

[0061] For example, the second surface (front surface; 30S2) of the semiconductor substrate 30 is provided with a floating diffusion portion (floating diffusion layer) FD 1 (region 36B in semiconductor substrate 30), FD 2 (region 37C in semiconductor substrate 30) and FD 3 (region 38C in the semiconductor substrate 30), transfer transistors Tr2 and Tr3, amplification transistor (modulation element) AMP, reset transistor RST, selection transistor SEL, and multilayer wiring layer 40. For example, the multilayer wiring layer 40 has a configuration in which wiring layers 41, 42, and 43 are stacked in an insulating layer 44.

[0062] Note that in the drawings, the first surface (surface 30S1 ) side of the semiconductor substrate 30 is referred to as the light incident side S1 , and the second surface (surface 30S2 ) side is referred to as the wiring layer side S2 .

[0063] The organic photoelectric conversion unit 20 includes a lower electrode 21, a semiconductor layer 23, a photoelectric conversion layer 24, and an upper electrode 25 stacked in sequence from the first surface (surface 30S1) side of the semiconductor substrate 30. In addition, an insulating layer 22 is provided between the lower electrode 21 and the semiconductor layer 23. The lower electrode 21 is formed separately for each imaging element 10A, for example. Although described in detail below, each lower electrode 21 includes a readout electrode 21A and an accumulation electrode 21B separated from each other by an insulating layer 22. The readout electrode 21A of the lower electrode 21 is electrically connected to the semiconductor layer 23 through an opening 22H provided in the insulating layer 22. Figure 1An example is shown in which the semiconductor layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are provided as a continuous layer common to a plurality of imaging elements 10A, but the semiconductor layer 23, the photoelectric conversion layer 24, and the upper electrode 25 may be formed separately for each imaging element 10A. For example, a dielectric film 26, an insulating film 27, and an interlayer insulating layer 28 are provided between the first surface (surface 30S1) of the semiconductor substrate 30 and the lower electrode 21. A protective layer 51 is provided above the upper electrode 25. For example, a light shielding film 52 is provided at a position corresponding to the readout electrode 21A in the protective layer 51. The light shielding film 52 does not cover at least the accumulation electrode 21B, but is provided to cover at least the region of the readout electrode 21A that is in direct contact with the semiconductor layer 23. Optical components such as a planarization layer (not shown) and an on-chip lens 53 are provided above the protective layer 51.

[0064] A through electrode 34 is provided between the first surface (surface 30S1) and the second surface (surface 30S2) of the semiconductor substrate 30. The through electrode 34 is electrically connected to the readout electrode 21A of the organic photoelectric conversion unit 20, and the organic photoelectric conversion unit 20 is connected to the gate Gamp of the amplifier transistor AMP and the reset transistor RST (reset transistor Tr1) through the through electrode 34. rst ) a source / drain region 36B. Reset transistor RST (reset transistor Tr1 rst ) one source / drain region 36B also serves as a floating diffusion FD 1 This enables the imaging element 10A to transfer charges generated in the organic photoelectric conversion section 20 on the first surface (surface 30S1 ) side of the semiconductor substrate 30 to the second surface (surface 30S2 ) side of the semiconductor substrate 30 in a favorable manner, thereby improving characteristics.

[0065] The lower end of the through electrode 34 is connected to a connection portion 41A in the wiring layer 41, and the connection portion 41A and the gate Gamp of the amplifier transistor AMP are connected to each other through a first lower contact 45. The connection portion 41A and the floating diffusion portion FD 1 (region 36B) are connected to each other, for example, through the second lower contact 46. The upper end of the through-electrode 34 is connected to the readout electrode 21A, for example, through the first upper contact 29A, the pad portion 39A, and the second upper contact 29B.

[0066] For example, the through electrode 34 is provided for each organic photoelectric converter 20 in each image pickup element 10A. The through electrode 34 has a gate Gamp and a floating diffusion FD as a connection between the organic photoelectric converter 20 and the amplifier transistor AMP. 1 , and serves as a transfer path for charges generated in the organic photoelectric conversion section 20.

[0067] The reset gate Grst of the reset transistor RST and the floating diffusion FD 1 (one source / drain region 36B of the reset transistor RST) is arranged adjacent to the floating diffusion FD. 1 The accumulated charge in is reset.

[0068] In the imaging element 10A according to the present embodiment, light entering the organic photoelectric conversion unit 20 from the upper electrode 25 side is absorbed by the photoelectric conversion layer 24. The excitons thus generated move to the interface between the electron donor and the electron acceptor included in the photoelectric conversion layer 24, and exciton separation is performed. In other words, the excitons are dissociated into electrons and holes. The charges (electrons and holes) generated here are transported to different electrodes by diffusion caused by the concentration difference between the carriers or by the internal electric field caused by the difference in work function between the anode (e.g., the upper electrode 25) and the cathode (e.g., the lower electrode 21), and are detected as photocurrent. In addition, by applying a potential between the lower electrode 21 and the upper electrode 25, the transport direction of electrons and holes can be controlled.

[0069] The structure and materials of each part are described below.

[0070] The organic photoelectric conversion section 20 is an organic photoelectric converter that absorbs light corresponding to a part or all of a selected wavelength band (for example, 400 nm to 700 nm) and generates electron-hole pairs.

[0071] As described above, the lower electrode 21 includes the readout electrode 21A and the accumulation electrode 21B which are separately formed. The readout electrode 21A is used to transfer the charges generated in the photoelectric conversion layer 24 to the floating diffusion FD. 1 For example, the readout electrode 21A is connected to the floating diffusion FD through the second upper contact 29B, the pad portion 39A, the first upper contact 29A, the through electrode 34, the connection portion 41A, and the second lower contact 46. 1 The accumulation electrode 21B is used to accumulate electrons of the charge generated in the photoelectric conversion layer 24 as signal charges in the semiconductor layer 23. The accumulation electrode 21B is provided in a region opposite to and covering the light receiving surfaces of the inorganic photoelectric conversion sections 32B and 32R formed in the semiconductor substrate 30. Preferably, the accumulation electrode 21B is larger than the readout electrode 21A. This makes it possible to accumulate a large amount of charge. Figure 4 As shown, the voltage applying circuit 60 is connected to the accumulation electrode 21B through wiring.

[0072] The lower electrode 21 is formed of a light-transmitting conductive film. Examples of the constituent material of the lower electrode 21 include indium tin oxide, Indium tin oxide with tin (Sn) added as a dopant, and Indium tin oxide with tin (Sn) added as a dopant. 2 O3 Indium tin oxide (ITO), crystalline ITO, and amorphous ITO. In addition to the above materials, tin oxide (SnO) to which a dopant is added can also be used as a constituent material of the lower electrode 21. 2 )-based material or a zinc oxide-based material to which a dopant is added. Examples of zinc oxide-based materials include: aluminum zinc oxide (AZO) to which aluminum (Al) is added as a dopant; gallium zinc oxide (GZO) to which gallium (Ga) is added; boron zinc oxide to which boron (B) is added; and indium zinc oxide (IZO) to which indium (In) is added. In addition, CuI, InSbO 4 、ZnMgO、CuInO 2 MgIN 2 O 4 、CdO、ZnSnO 3 or TiO 2 In addition, spinel oxides or YbFe 2 O 4 It should be noted that the lower electrode 21 formed by using any of the materials described above generally has a high work function and functions as an anode electrode.

[0073] The semiconductor layer 23 is arranged in the lower layer of the photoelectric conversion layer 24. Specifically, the semiconductor layer 23 is arranged between the insulating layer 22 and the photoelectric conversion layer 24. The semiconductor layer 23 is used to accumulate the signal charge generated in the photoelectric conversion layer 24. Preferably, the semiconductor layer 23 is formed using a material having a higher charge mobility and a wider band gap than the photoelectric conversion layer 24. For example, the band gap of the constituent material of the semiconductor layer 23 is preferably above 3.0 eV. Examples of such materials include oxide semiconductor materials such as IGZO and organic semiconductor materials, etc. Examples of organic semiconductor materials include transition metal disulfides, silicon carbide, diamond, graphene, carbon nanotubes, condensed polycyclic hydrocarbon compounds, and condensed heterocyclic compounds. The thickness of the semiconductor layer 23 is, for example, above 10 nm and below 300 nm. The semiconductor layer 23 composed of the above-mentioned materials is arranged in the lower layer of the photoelectric conversion layer 24. This can prevent the recombination of charges during charge accumulation and can improve the transmission efficiency.

[0074] The photoelectric conversion layer 24 converts light energy into electrical energy. The photoelectric conversion layer 24 according to the present embodiment absorbs light having a partial or full wavelength in a range of, for example, 400 nm or more and 700 nm or less. The photoelectric conversion layer 24, for example, includes two or more organic materials used as p-type semiconductors or n-type semiconductors, respectively. The photoelectric conversion layer 24 has a junction surface (p / n junction) between a p-type semiconductor and an n-type semiconductor in a layer. The p-type semiconductor relatively acts as an electron donor (donor), and the n-type semiconductor relatively acts as an electron acceptor (acceptor). The photoelectric conversion layer 24 provides a field in which the excitons generated when absorbing light are separated into electrons and holes. Specifically, the excitons are separated into electrons and holes at the interface (p / n junction) between the electron donor and the electron acceptor.

[0075] In addition to p-type semiconductors and n-type semiconductors, the photoelectric conversion layer 24 also includes an organic material or a so-called dye material. The organic material or dye material performs photoelectric conversion on light in a predetermined band and transmits light in another band. In the case of using three organic materials including a p-type semiconductor, an n-type semiconductor and a dye material to form the photoelectric conversion layer 24, the p-type semiconductor and the n-type semiconductor are preferably materials that are light-transmitting in the visible light region (e.g., 400nm to 700nm). The thickness of the photoelectric conversion layer 24 is, for example, greater than 25nm and less than 400nm. Preferably, the thickness of the photoelectric conversion layer 24 is greater than 50nm and less than 350nm. More preferably, the thickness of the photoelectric conversion layer 24 is greater than 150nm and less than 300nm.

[0076] In the present embodiment, for example, the photoelectric conversion layer 24 is formed to include a compound represented by the following general formula (1) as a dye material. The compound represented by general formula (1) is a BODIPY dye having, for example, electron acceptability and absorbing light of, for example, 450 nm or more and 650 nm or less.

[0077] [Chemical formula 3]

[0078]

[0079] (wherein, R1 and R4 each independently represent a hydrogen atom or a deuterium atom; R2 and R3 each independently represent an alkyl group, a cycloalkyl group, an alkoxy group or an aryl ether group; R5 and R6 each independently represent a halogen atom, a hydrogen atom or an alkyl group; R7 represents an aryl group, a heteroaryl group or an alkenyl group; M represents boron or an m-valent metal atom, and includes at least one of germanium, beryllium, magnesium, aluminum, chromium, iron, nickel, copper, zinc or platinum; L represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group; n represents an integer of 1 to 6, and when n-1 is 2 or more, each L independently represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group)

[0080] Specific examples of the compound represented by the above-mentioned general formula (1) include, for example, compounds represented by the following formulae (1-1) to (1-28).

[0081] [Chemical formula 4]

[0082]

[0083] [Chemical formula 5]

[0084]

[0085] [Chemical formula 6]

[0086]

[0087] [Chemical formula 7]

[0088]

[0089] Examples of another organic material constituting the photoelectric conversion layer 24 include fullerene or a fullerene derivative. In addition, examples of another organic material constituting the photoelectric conversion layer 24 also include a thiophene derivative in which benzodithiophene (BDT) is a mother skeleton or a chrysene derivative having a chrysene skeleton.

[0090] The above-mentioned organic materials function as a p-type semiconductor or an n-type semiconductor according to their combination.

[0091] It should be noted that the photoelectric conversion layer 24 may include organic materials other than the above materials. As organic materials other than the above materials, for example, any one of quinacridone, subphthalocyanine, pentacene, benzothienobenzothiophene, naphthalene, anthracene, phenanthrene, tetracene, pyrene, perylene, fluoranthene, and derivatives thereof is preferably used. Alternatively, polymers such as phenylene vinylene, fluorene, carbazole, indole, pyrrole, picoline, thiophene, acetylene, diacetylene, etc., or derivatives thereof may be used. In addition, preferably, metal complex dyes, cyanine dyes, merocyanine dyes, phenylxanthene dyes, triphenylmethane dyes, rhodacyanine dyes, xanthene dyes, macrocyclic azaannulene dyes, azulene dyes, naphthoquinone, anthraquinone dyes, chain compounds formed by condensation of fused polycyclic aromatic groups such as anthracene and pyrene and aromatic rings or heterocyclic compounds, or cyanine-like dyes formed by bonding two nitrogen-containing heterocyclic rings such as quinoline, benzothiophene and benzoxazole having a squarylium group and a croconicmethine group as a bonding chain, or bonded through a squarylium group or a croconicmethine group, etc. can be used. It should be noted that as the above-mentioned metal complex dye, a dithiol metal complex system dye, a metal phthalocyanine dye, a metal porphyrin dye, or a ruthenium complex dye is preferred, but the metal complex dye is not limited thereto.

[0092] The upper electrode 25 is formed of a light-transmitting conductive film, similar to the lower electrode 21. In the imaging device 1 using the imaging element 10A as one pixel, the upper electrode 25 may be provided separately for each pixel, or may be formed as a common electrode for each pixel. The thickness of the upper electrode 25 is, for example, 10 nm to 200 nm.

[0093] In addition to the photoelectric conversion layer 24 , other layers as organic layers may be provided between the semiconductor layer 23 and the photoelectric conversion layer 24 and between the photoelectric conversion layer 24 and the upper electrode 25 .

[0094] For example, Figure 5 The imaging element 10B shown in the figure can stack the semiconductor layer 23, the hole blocking layer 24A, the photoelectric conversion layer 24 and the electron blocking layer 24B in this order from the lower electrode 21. For example, the compound represented by the above general formula (1) mentioned as the constituent material of the photoelectric conversion layer 24 can be used for the hole blocking layer 24A and the electron blocking layer 24B.

[0095] Furthermore, an underlying layer and a hole transport layer may be provided between the lower electrode 21 and the photoelectric conversion layer 24 , and a work function adjustment layer, a buffer layer, or an electron transport layer may be provided between the photoelectric conversion layer 24 and the upper electrode 25 .

[0096] The insulating layer 22 is used to electrically separate the accumulation electrode 21B and the semiconductor layer 23 from each other. For example, the insulating layer 22 is provided on the interlayer insulating layer 28 to cover the lower electrode 21. In addition, the insulating layer 22 is provided with an opening 22H above the readout electrode 21A of the lower electrode 21. The readout electrode 21A and the semiconductor layer 23 are electrically connected to each other through the opening 22H. For example, the insulating layer 22 is made of silicon oxide (SiO x ), silicon nitride (SiN x ) and silicon oxynitride (SiON), or a stacked film including two or more thereof. The thickness of the insulating layer 22 is, for example, 20 nm to 500 nm.

[0097] The dielectric film 26 is used to prevent light reflection caused by the difference in refractive index between the semiconductor substrate 30 and the insulating film 27. Preferably, the material of the dielectric film 26 is a material having a refractive index between the refractive index of the semiconductor substrate 30 and the refractive index of the insulating film 27. In addition, as the material of the dielectric film 26, it is preferable to use a material that can form a film having, for example, a negative fixed charge. Alternatively, as the material of the dielectric film 26, it is preferable to use a semiconductor material or a conductive material having a band gap wider than that of the semiconductor substrate 30. This can suppress the generation of dark current at the interface of the semiconductor substrate 30. Such materials include hafnium oxide (HfO x ), aluminum oxide (AlO x )、ZrO x ), tantalum oxide (TaO x ), titanium oxide (TiO x ), lanthanum oxide (LaO x ), praseodymium oxide (PrO x ), cerium oxide (CeO x ), neodymium oxide (NdO x ), promethium oxide (PmO x ), samarium oxide (SmO x ), europium oxide (EuO x ), Gadolinium oxide (GdO x ), terbium oxide (TbO x ), Dysprosium oxide (DyO x ), holmium oxide (HoO x ), thulium oxide (TmO x ), Ytterbium oxide (YbO x ), Lutetium oxide (LuO x ), yttrium oxide (YOx ), Hafnium Nitride (HfN x ), aluminum nitride (AlN x ), Hafnium Oxynitride (HfO x N y ) and aluminum oxynitride (AlO x N y )wait.

[0098] The insulating film 27 is provided on the dielectric film 26 formed on the first surface (surface 30S1) of the semiconductor substrate 30 and the side surface of the through hole 30H. The insulating film 27 is used to electrically insulate the through electrode 34 from the semiconductor substrate 30. Examples of the material of the insulating film 27 include silicon oxide (SiO x )、TEOS、Silicon Nitride (SiN x ) and silicon oxynitride (SiON), etc.

[0099] For example, the interlayer insulating layer 28 is made of silicon oxide (SiO x )、TEOS、Silicon Nitride (SiN x ) and silicon oxynitride (SiON), etc., or a stacked film comprising two or more thereof.

[0100] The protective layer 51 is made of a light-transmitting material. For example, the protective layer 51 is made of silicon oxide (SiO x ), Silicon Nitride (SiN x ) and silicon oxynitride (SiON), or a stacked film of two or more thereof. The thickness of the protective layer 51 is, for example, 100 nm to 30,000 nm.

[0101] For example, the semiconductor substrate 30 is composed of an n-type silicon (Si) substrate, and the semiconductor substrate 30 includes a p-well 31 in a predetermined region (for example, the pixel portion 1a). The second surface (surface 30S2) of the p-well 31 is provided with the above-mentioned transfer transistors Tr2 and Tr3, the amplifier transistor AMP, the reset transistor RST, the selection transistor SEL, and the like. Figure 2 As shown, a peripheral portion (peripheral portion 1 b ) of the semiconductor substrate 30 is provided with, for example, a pixel readout circuit 110 and a pixel drive circuit 120 each including a logic circuit or the like.

[0102] Reset transistor RST (reset transistor Tr1 rst ) is used to transfer from the organic photoelectric conversion unit 20 to the floating diffusion unit FD 1 The charge of the reset transistor Tr1 is reset, and the reset transistor RST is composed of, for example, a MOS transistor. Specifically, the reset transistor Tr1 rstThe reset gate Grst includes a reset gate Grst, a channel formation region 36A, and source / drain regions 36B and 36C. The reset gate Grst is connected to a reset line RST. 1 . Reset transistor Tr1 rst One source / drain region 36B also serves as a floating diffusion FD 1 . Reset transistor Tr1 rst Another source / drain region 36C included in is connected to the power supply line VDD.

[0103] The amplifier transistor AMP is a modulation element that modulates the amount of charge generated in the organic photoelectric conversion section 20 into a voltage, and the amplifier transistor AMP is composed of, for example, a MOS transistor. Specifically, the amplifier transistor AMP includes a gate Gamp, a channel formation region 35A, and source / drain regions 35B and 35C. The gate Gamp is connected to the readout electrode 21A and the reset transistor Tr1 through the first lower contact 45, the connection portion 41A, the second lower contact 46, the through electrode 34, and the like. rst A source / drain region 36B (floating diffusion FD 1 ). In addition, a source / drain region 35B is connected to the reset transistor Tr1 rst Another source / drain region 36C included in the shared region, and one source / drain region 35B is connected to the power supply line VDD.

[0104] Select transistor SEL (select transistor TR1 sel ) includes a gate Gsel, a channel forming region 34A, and source / drain regions 34B and 34C. The gate Gsel is connected to a selection line SEL 1 One source / drain region 34B shares an area with another source / drain region 35C included in the amplifier transistor AMP, and the other source / drain region 34C is connected to a signal line (data output line) VSL 1 .

[0105] The inorganic photoelectric conversion units 32B and 32R each have a pn junction in a predetermined region of the semiconductor substrate 30. Since light having different wavelengths is absorbed in the silicon substrate according to the depth of light incidence, the inorganic photoelectric conversion units 32B and 32R are respectively capable of dispersing light in the vertical direction. The inorganic photoelectric conversion unit 32B selectively detects blue light to accumulate signal charges corresponding to blue, and the inorganic photoelectric conversion unit 32B is arranged at a depth at which blue light can be effectively photoelectrically converted. The inorganic photoelectric conversion unit 32R selectively detects red light to accumulate signal charges corresponding to red, and the inorganic photoelectric conversion unit 32R is arranged at a depth at which red light can be effectively photoelectrically converted. It should be noted that blue (B) is a color corresponding to a band of, for example, 430nm to 480nm, and red (R) is a color corresponding to a band of, for example, 600nm to 750nm. It is sufficient as long as the inorganic photoelectric conversion units 32B and 32R are respectively capable of detecting light of a portion of or all of each band.

[0106] For example, the inorganic photoelectric conversion unit 32B includes a p+ region used as a hole accumulation layer and an n region used as an electron accumulation layer. For example, the inorganic photoelectric conversion unit 32R includes a p+ region used as a hole accumulation layer and an n region used as an electron accumulation layer (having a pnp stacking structure). The n region of the inorganic photoelectric conversion unit 32B is connected to the vertical transfer transistor Tr2. The p+ region of the inorganic photoelectric conversion unit 32B is bent along the transfer transistor Tr2 and leads to the p+ region of the inorganic photoelectric conversion unit 32R.

[0107] Transfer transistor Tr2 (transmission transistor TR2 trs ) is used to transfer the signal charge corresponding to blue generated and accumulated in the inorganic photoelectric conversion unit 32B to the floating diffusion unit FD 2 The inorganic photoelectric conversion unit 32B is formed at a position deeper than the second surface (surface 30S2) of the semiconductor substrate 30, and therefore, the transfer transistor TR2 of the inorganic photoelectric conversion unit 32B trs It is preferably composed of a vertical transistor. Transfer transistor TR2 trs Connected to the transmission gate line TG 2 Floating Diffusion FD 2 Set the pass transistor TR2 trs The charge accumulated in the inorganic photoelectric conversion unit 32B is read out to the floating diffusion FD through a transfer channel formed along the gate Gtrs2. 2 .

[0108] Transfer transistor Tr3 (transmission transistor TR3 trs ) is used to transfer the signal charge corresponding to red generated and accumulated in the inorganic photoelectric conversion unit 32R to the floating diffusion unit FD3 . Transfer transistor Tr3 (transmission transistor TR3 trs ) is composed of, for example, a MOS transistor. Transfer transistor TR3 trs Connected to the transmission gate line TG 3 Floating Diffusion FD 3 Set the pass transistor TR3 trs The charge accumulated in the inorganic photoelectric conversion unit 32R is read out to the floating diffusion FD through a transfer channel formed along the gate Gtrs3. 3 .

[0109] A reset transistor TR2 is further provided on the second surface (surface 30S2) side of the semiconductor substrate 30. rst , Amplifier transistor TR2 amp and select transistor TR2 sel . Reset transistor TR2 rst , Amplifier transistor TR2 amp and select transistor TR2 sel The control unit of the inorganic photoelectric conversion unit 32B is constituted. In addition, a reset transistor TR3 is also provided. rst , Amplifier transistor TR3 amp and select transistor TR3 sel . Reset transistor TR3 rst , Amplifier transistor TR3 amp and select transistor TR3 sel The control unit constitutes the inorganic photoelectric conversion unit 32R.

[0110] Reset transistor TR2 rst It includes a gate, a channel formation region, and a source / drain region. Reset transistor TR2 rst The gate is connected to the reset line RST 2 , and reset transistor TR2 rst A source / drain region of the reset transistor TR2 is connected to the power supply line VDD. rst The other source / drain region also serves as a floating diffusion FD 2 .

[0111] Amplifier transistor TR2 amp It includes a gate, a channel forming region, and a source / drain region. The gate is connected to the reset transistor TR2 rst The other source / drain region (floating diffusion FD 2 ). Amplifier transistor TR2 amp A source / drain region included in the reset transistor TR2 rstA source / drain region shared region included in the amplifying transistor TR2 amp A source / drain region included in is connected to a power supply line VDD.

[0112] Select transistor TR2 sel It includes a gate, a channel forming region, and a source / drain region. The gate is connected to the select line SEL 2 . Select transistor TR2 sel A source / drain region included in the amplifying transistor TR2 amp Another source / drain region included in the shared region. Select transistor TR2 sel Another source / drain region included in the 2 .

[0113] Reset transistor TR3 rst It includes a gate, a channel formation region, and a source / drain region. Reset transistor TR3 rst The gate is connected to the reset line RST 3 , and reset transistor TR3 rst A source / drain region included in the reset transistor TR3 is connected to the power supply line VDD. rst The other source / drain region included in the floating diffusion FD also serves as a floating diffusion 3 .

[0114] Amplifier transistor TR3 amp It includes a gate, a channel forming region, and a source / drain region. The gate is connected to the reset transistor TR3 rst Another source / drain region (floating diffusion FD 3 ). Amplifier transistor TR3 amp A source / drain region included in the reset transistor TR3 rst A source / drain region shared region included in the amplifying transistor TR3 amp A source / drain region included in is connected to a power supply line VDD.

[0115] Select transistor TR3 sel It includes a gate, a channel forming region, and a source / drain region. The gate is connected to the select line SEL 3 . Select transistor TR3 sel A source / drain region included in the amplifying transistor TR3 amp Another source / drain region included in the shared region. Select transistor TR3 sel Another source / drain region included in the 3 .

[0116] Reset line RST 1 , RST 2 and RST 3 , select line SEL 1 , SEL 2 and SEL 3 and the transmission gate line TG 2 and TG 3 They are respectively connected to the vertical drive circuits that constitute the drive circuit. Signal line (data output line) VSL 1 、VSL 2 and VSL 3 Connected to the column signal processing circuit that constitutes the drive circuit.

[0117] For example, the first lower contact 45, the second lower contact 46, the first upper contact 29A, the second upper contact 29B and the third upper contact 29C are respectively composed of doped silicon materials such as PDAS (Phosphorus Doped Amorphous Silicon) or metal materials such as aluminum (Al), tungsten (W), titanium (Ti), cobalt (Co), hafnium (Hf) or tantalum (Ta).

[0118] (1-2. Method for manufacturing imaging element)

[0119] For example, the image pickup element 10A according to the present embodiment can be manufactured as follows.

[0120] Figures 6 to 10 The manufacturing method of the imaging element 10A is shown in the order of steps. Figure 6 As shown, for example, a p-well 31 is formed as a well of the first conductivity type in the semiconductor substrate 30. Inorganic photoelectric conversion sections 32B and 32R of the second conductivity type (for example, n-type) are formed in the p-well 31. A p+ region is formed near the first surface (surface 30S1) of the semiconductor substrate 30.

[0121] Or Figure 6 As shown, for example, a floating diffusion portion FD is formed on the second surface (surface 30S2) of the semiconductor substrate 30. 1 To FD 3The n+ region of the semiconductor substrate 30 is formed, and a gate insulating layer 33 and a gate wiring layer 47 are formed. The gate wiring layer 47 includes the gates of the transfer transistor Tr2, the transfer transistor Tr3, the selection transistor SEL, the amplifier transistor AMP, and the reset transistor RST. Thus, the transfer transistor Tr2, the transfer transistor Tr3, the selection transistor SEL, the amplifier transistor AMP, and the reset transistor RST are formed. In addition, a multilayer wiring layer 40 is formed on the second surface (surface 30S2) of the semiconductor substrate 30. The multilayer wiring layer 40 includes wiring layers 41 to 43 and an insulating layer 44. The wiring layers 41 to 43 include a first lower contact 45, a second lower contact 46, and a connecting portion 41A.

[0122] As a base of the semiconductor substrate 30, for example, an SOI (Silicon on Insulator) substrate in which the semiconductor substrate 30, a buried oxide film (not shown), and a holding substrate (not shown) are stacked is used. Figure 6 The buried oxide film and the holding substrate are not shown in FIG. 3 , but are bonded to the first surface (surface 30S1 ) of the semiconductor substrate 30. Annealing treatment is performed after the ion implantation.

[0123] Next, a support substrate (not shown) or another semiconductor substrate is bonded to the second surface (surface 30S2) side (multilayer wiring layer 40 side) of the semiconductor substrate 30, and then turned upside down. Subsequently, the semiconductor substrate 30 is separated from the buried oxide film of the SOI substrate and the holding substrate to expose the first surface (surface 30S1) of the semiconductor substrate 30. The above steps can be performed using techniques used in a general CMOS process such as ion implantation and CVD (Chemical Vapor Deposition).

[0124] Next, if Figure 7 As shown, the semiconductor substrate 30 is processed from the first surface (surface 30S1) side by dry etching, for example, to form a ring-shaped through hole 30H. Figure 7 As shown, the depth of the through hole 30H extends from the first surface (surface 30S1 ) to the second surface (surface 30S2 ) of the semiconductor substrate 30 , and reaches, for example, the connection portion 41A.

[0125] Then, if Figure 8As shown, a dielectric film 26 is formed on the first surface (surface 30S1) of the semiconductor substrate 30 and the side surface of the through hole 30H by using, for example, an atomic layer deposition (ALD) method. A continuous dielectric film 26 is thereby formed on the first surface (surface 30S1) of the semiconductor substrate 30 and the side and bottom surfaces of the through hole 30H. Next, an insulating film 27 is formed on the first surface (surface 30S1) of the semiconductor substrate 30 and in the through hole 30H. Thereafter, the insulating film 27 and the dielectric film 26 formed on the bottom surface of the through hole 30H are removed, for example, by dry etching, so that the connecting portion 41A is exposed. It should be noted that in this case, the thickness of the insulating film 27 on the first surface (surface 30S1) is also reduced. Subsequently, a conductive film is formed on the insulating film 27 and in the through hole 30H. Thereafter, a photoresist PR is formed at a predetermined position on the conductive film. Next, the photoresist PR is etched and removed, so that the through-electrode 34 including the protruding portion is formed on the first surface (the surface 30S1 ) of the semiconductor substrate 30 .

[0126] Next, if Fig. 9 As shown, an insulating film constituting the interlayer insulating layer 28 is formed on the insulating film 27 and the through electrode 34. Subsequently, the first upper contact 29A, the pad portions 39A and 39B, the second upper contact 29B, and the third upper contact 29C are formed on the through electrode 34, and the front surface of the interlayer insulating layer 28 is planarized by using a CMP (Chemical Mechanical Polishing) method. Next, a conductive film 21x is formed on the interlayer insulating layer 28. Thereafter, a photoresist PR is formed at a predetermined position of the conductive film 21x.

[0127] Then, if Fig.10 As shown, the readout electrode 21A and the accumulation electrode 21B are formed by etching and removing the photoresist PR.

[0128] After that, the insulating layer 22 is formed on the interlayer insulating layer 28, the readout electrode 21A, and the accumulation electrode 21B, and then the opening 22H is provided on the readout electrode 21A. Next, the semiconductor layer 23, the photoelectric conversion layer 24, and the upper electrode 25 are sequentially formed on the insulating layer 22. Finally, the protective layer 51, the light shielding film 52, and the on-chip lens 53 are provided on the upper electrode 25. As described above, the Figure 1 The imaging element 10A is shown.

[0129] It should be noted that in the case of using an organic material to form the semiconductor layer 23 and another organic layer, it is preferred to form the semiconductor layer 23 and another organic layer continuously in a vacuum step (in an in-situ vacuum process). In addition, the method for forming the photoelectric conversion layer 24 is not necessarily limited to the technology using the vacuum evaporation method. Other methods, such as spin coating technology or printing technology, etc., can also be used. In addition, according to the material constituting the transparent electrode, the method for forming the transparent electrode (lower electrode 21 and upper electrode 25) includes: physical vapor deposition methods (PVD methods) such as vacuum evaporation, reactive evaporation, various sputtering methods, electron beam evaporation, and ion plating, hot sol methods, methods for pyrolyzing organic metal compounds, spraying methods, immersion methods, various chemical vapor deposition methods (CVD methods) including MOCVD methods, chemical plating methods, and electrolytic plating methods.

[0130] In the imaging element 10A, when light enters the organic photoelectric conversion unit 20 through the on-chip lens 53, the light sequentially passes through the organic photoelectric conversion unit 20 and the inorganic photoelectric conversion units 32B and 32R. When the light passes through the organic photoelectric conversion unit 20 and the inorganic photoelectric conversion units 32B and 32R, the green light, the blue light, and the red light are photoelectrically converted, respectively. The signal acquisition operation of each color is described below.

[0131] (Green signal is obtained by the organic photoelectric conversion unit 20)

[0132] First, green light among the light entering the image pickup element 10A is selectively detected (absorbed) and photoelectrically converted by the organic photoelectric conversion section 20 .

[0133] The organic photoelectric conversion unit 20 is connected to the gate Gamp of the amplifier transistor AMP and the floating diffusion FD through the through electrode 34. 1 Therefore, the electrons in the electron-hole pairs generated in the organic photoelectric conversion unit 20 are extracted from the lower electrode 21 side, and then transferred to the second surface (surface 30S2) side of the semiconductor substrate 30 through the through electrode 34, and accumulated in the floating diffusion FD. 1 At the same time, the amplifier transistor AMP modulates the amount of charge generated in the organic photoelectric conversion unit 20 into a voltage.

[0134] In addition, the reset gate Grst of the reset transistor RST and the floating diffusion FD 1 This allows the reset transistor RST to transfer the floating diffusion FD 1 The accumulated charge in is reset.

[0135] Here, the organic photoelectric conversion unit 20 is connected not only to the amplifier transistor AMP but also to the floating diffusion unit FD via the through electrode 34. 1, so that the reset transistor RST can easily reset the charges accumulated in the floating diffusion section FD 1 to reset the charges therein.

[0136] On the other hand, when the through electrode 34 is not connected to the floating diffusion section FD 1 , it is difficult to reset the charges accumulated in the floating diffusion section FD 1 to reset the charges therein. A large voltage must be applied to pull the charges out to the upper electrode 25 side. Therefore, the photoelectric conversion layer 24 may be damaged. In addition, the structure that can reset in a short time period results in an increase in dark time noise, thus becoming a trade-off relationship. Therefore, such a structure is difficult.

[0137] Fig.11 An operation example of the imaging element 10A is shown. (A) represents the potential of the accumulation electrode 21B; (B) represents the potential of the floating diffusion section FD 1 (readout electrode 21A); and (C) represents the gate (Grst) potential of the reset transistor TR1 rst . In the imaging element 10A, voltages are applied to the readout electrode 21A and the accumulation electrode 21B, respectively.

[0138] In the imaging element 10A, during the accumulation period, the drive circuit applies the potential V1 to the readout electrode 21A and the potential V2 to the accumulation electrode 21B. Here, it is assumed that the potentials V1 and V2 satisfy V2 > V1. Therefore, the charges (signal charges; electrons) generated by photoelectric conversion are attracted to the accumulation electrode 21B and accumulated in the region of the semiconductor layer 23 opposite to the accumulation electrode 21B (accumulation period). Incidentally, the potential of the region of the semiconductor layer 23 opposite to the accumulation electrode 21B has a value that becomes more negative as the time of photoelectric conversion elapses. It should be noted that holes are transferred from the upper electrode 25 to the drive circuit.

[0139] In the imaging element 10A, the reset operation is performed in the second part of the accumulation period. Specifically, at time t1, the scanning section changes the voltage of the reset signal RST from low level to high level. This causes the reset transistor TR1 in the unit pixel P rst to conduct. As a result, the voltage of the floating diffusion section FD 1 is set to the power supply voltage, and the voltage of the floating diffusion section FD 1 is reset (reset period).

[0140] After the reset operation is completed, the charges are read out. Specifically, at time t2, the drive circuit applies the potential V3 to the readout electrode 21A and the potential V4 to the accumulation electrode 21B. Here, it is assumed that the potentials V3 and V4 satisfy V3 < V4. Therefore, the charges accumulated in the region corresponding to the accumulation electrode 21B are read out from the readout electrode 21A to the floating diffusion section FD1 In other words, the charges accumulated in the semiconductor layer 23 are read out to the control section (transfer period).

[0141] After the readout operation is completed, the drive circuit applies the potential V1 to the readout electrode 21A again, and applies the potential V2 to the accumulation electrode 21B again. Therefore, the charges generated by the photoelectric conversion are attracted to the accumulation electrode 21B and accumulated in the region of the semiconductor layer 23 opposite to the accumulation electrode 21B (accumulation period).

[0142] (Blue signal and red signal are obtained by the inorganic photoelectric conversion sections 32B and 32R)

[0143] Subsequently, the blue light and the red light of the light transmitted through the organic photoelectric conversion section 20 are absorbed and photoelectrically converted in sequence by the inorganic photoelectric conversion section 32B and the inorganic photoelectric conversion section 32R, respectively. In the inorganic photoelectric conversion section 32B, electrons corresponding to the incident blue light are accumulated in the n region of the inorganic photoelectric conversion section 32B, and the accumulated electrons are transferred to the floating diffusion section FD through the transfer transistor Tr2. 2 Similarly, in the inorganic photoelectric conversion section 32R, electrons corresponding to the incident red light are accumulated in the n region of the inorganic photoelectric conversion section 32R, and the accumulated electrons are transferred to the floating diffusion section FD through the transfer transistor Tr3. 3 .

[0144] (1-3. Actions and Effects)

[0145] In the imaging element 10A according to the present embodiment, the organic layer (e.g., the photoelectric conversion layer 24) constituting the organic photoelectric conversion section 20 is formed by using a compound represented by the above-mentioned general formula (1) which includes hydrogen atoms at the first position (R1) and the seventh position (R4). Therefore, an imaging element having high selectivity for a desired wavelength band (e.g., a green wavelength band) can be obtained. This is described below.

[0146] In recent years, image sensors are being miniaturized and required to have higher sensitivity. To this end, as described above, photoelectric conversion elements having an organic layer including a compound represented by general formula (2) having an alkyl group such as a methyl group at R1 and R4 have been developed.

[0147] Although described in detail below, the photoelectric conversion element having an organic layer containing the compound represented by the above general formula (2) has unsatisfactory selectivity (color selectivity) for a desired wavelength band (eg, green wavelength band). Therefore, the photoelectric conversion element is required to have higher color selectivity.

[0148] On the other hand, for example, in the imaging element 10A according to the present embodiment, the photoelectric conversion layer 24 is formed by using a compound having hydrogen atoms at R1 and R4 represented by the general formula (1). Although described in detail in the following embodiment, the compound represented by the general formula (1) has a larger difference of λ1-λ2 than the compound represented by the above-mentioned general formula (2). λ1 represents the excitation wavelength of the oscillation state of transitioning from the ground state S0 to the first excited state S1 (S0→S1). λ2 represents the excitation wavelength of the oscillation state of transitioning from the ground state S0 to the second excited state S2 (S0→S2). Therefore, the imaging element 10A has high selectivity for a desired band (for example, a green band).

[0149] As described above, in this embodiment, it is possible to provide an image pickup element 10A having high color selectivity and excellent spectral characteristics, and an image pickup device 1 including the image pickup element 10A.

[0150] Next, the second embodiment and the third embodiment of the present disclosure are described. Components similar to those of the first embodiment described above are given the same reference numerals, and their description is omitted as appropriate.

[0151] <2. Second Implementation Method>

[0152] Fig.12 The cross-sectional configuration of an image pickup element (image pickup element 10C) according to the second embodiment of the present disclosure is shown. The image pickup element 10C constitutes, for example, one pixel (unit pixel P) of an image pickup device (image pickup device 1) such as a CMOS image sensor used in electronic equipment such as a digital camera or a video camera. The image pickup element 10C according to the present embodiment includes two organic photoelectric conversion units 20 and 70 stacked in the vertical direction and one inorganic photoelectric conversion unit 32.

[0153] The organic photoelectric conversion units 20 and 70 and the inorganic photoelectric conversion unit 32 perform photoelectric conversion by selectively detecting light of a wavelength band, respectively. Specifically, for example, as in the first embodiment described above, the organic photoelectric conversion unit 20 acquires a color signal of green (G). The organic photoelectric conversion unit 70 acquires a color signal of blue (B), for example. The inorganic photoelectric conversion unit 32 acquires a color signal of red (R), for example. Therefore, the imaging element 10C is capable of acquiring a plurality of color signals in one pixel without using any color filter.

[0154] The organic photoelectric conversion unit 70 is stacked, for example, above the organic photoelectric conversion unit 20. Like the organic photoelectric conversion unit 20, the organic photoelectric conversion unit 70 has a structure in which a lower electrode 71, a semiconductor layer 73, a photoelectric conversion layer 74, and an upper electrode 75 are stacked in order from the first surface (surface 30S1) side of the semiconductor substrate 30. In addition, an insulating layer 72 is provided between the lower electrode 71 and the semiconductor layer 73. The lower electrode 71 is formed separately for each imaging element 10C, for example. Although it will be described in detail below, each lower electrode 71 includes a readout electrode 71A and an accumulation electrode 71B separated from each other via an insulating layer 72. The readout electrode 71A of the lower electrode 71 is electrically connected to the semiconductor layer 73 through an opening 72H provided in the insulating layer 72. Fig.12 An example is shown in which the semiconductor layer 73, the photoelectric conversion layer 74, and the upper electrode 75 are formed separately for each imaging element 10C. However, for example, the semiconductor layer 73, the photoelectric conversion layer 74, and the upper electrode 75 may be formed as a continuous layer common to a plurality of imaging elements 10C.

[0155] The photoelectric conversion layer 74 converts light energy into electrical energy. Like the photoelectric conversion layer 24, the photoelectric conversion layer 74 includes two or more organic materials used as p-type semiconductors or n-type semiconductors, respectively. In addition to the p-type semiconductor and the n-type semiconductor, the photoelectric conversion layer 74 also includes an organic material or a so-called dye material. The organic material or the dye material performs photoelectric conversion on light in a predetermined band and transmits light in another band. In the case where the photoelectric conversion layer 74 is formed using three organic materials including a p-type semiconductor, an n-type semiconductor and a dye material, the p-type semiconductor and the n-type semiconductor are preferably materials having light transmittance in the visible light region (e.g., 400nm to 700nm). The thickness of the photoelectric conversion layer 74 is, for example, 25nm or more and 400nm or less. Preferably, the thickness of the photoelectric conversion layer 74 is 50nm or more and 350nm or less. More preferably, the thickness of the photoelectric conversion layer 74 is 150nm or more and 300nm or less. Examples of dye materials used for the photoelectric conversion layer 74 include coumarin and diazo compounds or their derivatives, etc.

[0156] Two through electrodes 34X and 34Y are provided between the first surface (surface 30S1 ) and the second surface (surface 30S2 ) of the semiconductor substrate 30 .

[0157] As in the first embodiment described above, the through electrode 34X is electrically connected to the readout electrode 21A of the organic photoelectric conversion section 20, and the organic photoelectric conversion section 20 is connected to the gate Gamp of the amplifier transistor AMP and the reset transistor RST (reset transistor Tr1) through the through electrode 34X. rst ) a source / drain region 36B1. Reset transistor RST (reset transistor Tr1rst ) one source / drain region 36B1 also serves as a floating diffusion FD 1 The upper end of the through-electrode 34X is connected to the readout electrode 21A through, for example, the first upper contact 29A, the pad portion 39A, and the second upper contact 29B.

[0158] The through electrode 34Y is electrically connected to the readout electrode 71A of the organic photoelectric conversion unit 70, and the organic photoelectric conversion unit 70 is connected to the gate Gamp of the amplifier transistor AMP and the reset transistor RST (reset transistor Tr2) through the through electrode 34Y. rst ) a source / drain region 36B2. Reset transistor RST (reset transistor Tr2 rst ) one source / drain region 36B2 also serves as a floating diffusion FD 2 The upper end of the through electrode 34Y is connected to the readout electrode 71A through, for example, the fourth upper contact 79A, the pad portion 69A, the fifth upper contact 79B, the pad portion 69B, and the sixth upper contact 79C. In addition, the pad 69C is connected to the accumulation electrode 71B of the lower electrode 71 through the seventh upper contact 79D. The lower electrode 71 is included in the organic photoelectric conversion unit 70.

[0159] As described above, the image pickup element 10C according to the present embodiment has a structure in which two organic photoelectric conversion units 20 and 70 and one inorganic photoelectric conversion unit 32 are stacked. As in the above-mentioned first embodiment, for example, the photoelectric conversion layer 24 included in the organic photoelectric conversion unit 20 that obtains a color signal of green (G) is formed by using a compound represented by the above-mentioned general formula (1). Therefore, effects similar to those of the above-mentioned first embodiment can be obtained.

[0160] <3. Third Implementation Plan>

[0161] Fig.13 The cross-sectional structure of an imaging element (imaging element 10D) according to the third embodiment of the present disclosure is shown. The imaging element 10D constitutes, for example, one pixel (unit pixel P) of an imaging device 1 such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in electronic devices such as digital cameras or video cameras. The imaging element 10D according to the present embodiment has a structure in which a red photoelectric conversion unit 90R, a green photoelectric conversion unit 90G, and a blue photoelectric conversion unit 90B are sequentially stacked above a semiconductor substrate 80 via an insulating layer 96. The red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G, and the blue photoelectric conversion unit 90B are respectively formed by using organic materials.

[0162] The red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G, and the blue photoelectric conversion unit 90B include organic photoelectric conversion layers 92R, 92G, and 92B between the electrode pairs, respectively. Specifically, the red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G, and the blue photoelectric conversion unit 90B include organic photoelectric conversion layers 92R, 92G, and 92B between the first electrode 91R and the second electrode 93R, between the first electrode 91G and the second electrode 93G, and between the first electrode 91B and the second electrode 93B, respectively.

[0163] An on-chip lens 98L is provided above the blue photoelectric conversion unit 90B via a protective layer 97 and an on-chip lens layer 98. A red power storage layer 810R, a green power storage layer 810G, and a blue power storage layer 810B are provided in the semiconductor substrate 80. Light entering the on-chip lens 98L is photoelectrically converted by the red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G, and the blue photoelectric conversion unit 90B, and signal charges are transmitted from the red photoelectric conversion unit 90R to the red power storage layer 810R, from the green photoelectric conversion unit 90G to the green power storage layer 810G, and from the blue photoelectric conversion unit 90B to the blue power storage layer 810B, respectively. Although the signal charges may be electrons or holes generated by photoelectric conversion, the following description takes the case where electrons are read out as signal charges as an example.

[0164] For example, the semiconductor substrate 80 is composed of a p-type silicon substrate. The red storage layer 810R, the green storage layer 810G, and the blue storage layer 810B provided in the semiconductor substrate 80 include n-type semiconductor regions, respectively. The signal charge (electrons) provided from the red photoelectric conversion unit 90R, the green photoelectric conversion unit 90G, and the blue photoelectric conversion unit 90B are accumulated in these n-type semiconductor regions. For example, the n-type semiconductor regions of the red storage layer 810R, the green storage layer 810G, and the blue storage layer 810B are formed by doping n-type impurities such as phosphorus (P) or arsenic (As) in the semiconductor substrate 80. It should be noted that the semiconductor substrate 80 can be provided on a supporting substrate (not shown) made of glass or the like.

[0165] The semiconductor substrate 80 is provided with pixel transistors. Each pixel transistor is used to read out electrons from the red power storage layer 810R, the green power storage layer 810G, and the blue power storage layer 810B, and transmit the electrons to, for example, a vertical signal line (for example, the following Fig.14 The floating diffusions of these pixel transistors are provided in the semiconductor substrate 80. These floating diffusions are connected to the red power storage layer 810R, the green power storage layer 810G, and the blue power storage layer 810B. Each floating diffusion is composed of an n-type semiconductor region.

[0166] For example, the insulating layer 96 is made of silicon oxide (SiOx ), Silicon Nitride (SiN x ), silicon oxynitride (SiON) and hafnium oxide (HfO x ) or a laminated film containing two or more of them. In addition, the insulating layer 96 can be formed using an organic insulating material. Although not shown, the insulating layer 96 is provided with plugs and electrodes. Each plug is used to connect the red storage layer 810R and the red photoelectric conversion unit 90R, the green storage layer 810G and the green photoelectric conversion unit 90G, and the blue storage layer 810B and the blue photoelectric conversion unit 90B.

[0167] The red photoelectric conversion unit 90R includes a first electrode 91R, an organic photoelectric conversion layer 92R, and a second electrode 93R in order from a position close to the semiconductor substrate 80. The green photoelectric conversion unit 90G includes a first electrode 91G, an organic photoelectric conversion layer 92G, and a second electrode 93G in order from a position close to the red photoelectric conversion unit 90R. The blue photoelectric conversion unit 90B includes a first electrode 91B, an organic photoelectric conversion layer 92B, and a second electrode 93B in order from a position close to the green photoelectric conversion unit 90G. An insulating layer 94 is further provided between the red photoelectric conversion unit 90R and the green photoelectric conversion unit 90G, and an insulating layer 95 is further provided between the green photoelectric conversion unit 90G and the blue photoelectric conversion unit 90B. The red photoelectric conversion region 90R, the green photoelectric conversion region 90G and the blue photoelectric conversion region 90B respectively selectively absorb red (e.g., a wavelength of greater than 600nm and less than 700nm) light, green (e.g., a wavelength of greater than 500nm and less than 600nm) light and blue (e.g., a wavelength of greater than 400nm and less than 500nm) light to generate electron-hole pairs.

[0168] The first electrodes 91R, 91G, and 91B extract signal charges generated in the organic photoelectric conversion layer 92R, 92G, and 92B, respectively. The first electrodes 91R, 91G, and 91B are provided for each pixel, for example.

[0169] For example, the first electrodes 91R, 91G and 91B are respectively made of a conductive material having light transmittance. Specifically, the first electrodes 91R, 91G and 91B are respectively made of ITO. For example, the first electrodes 91R, 91G and 91B can be respectively made of a tin oxide-based material or a zinc oxide-based material. The tin oxide-based material is obtained by doping a dopant in tin oxide. Examples of zinc oxide-based materials include: aluminum zinc oxide in which aluminum is added as a dopant to zinc oxide; gallium zinc oxide in which gallium is added as a dopant to zinc oxide; and indium zinc oxide in which indium is added as a dopant to zinc oxide, etc. In addition, IGZO, CuI, InSbO4 、ZnMgO、CuInO 2 MgIn 2 O 4 , CdO and ZnSnO 3 Etc. For example, the thicknesses of the first electrodes 91R, 91G, and 91B are respectively 50 nm to 500 nm.

[0170] For example, an electron transport layer may be provided between the first electrode 91R and the organic photoelectric conversion layer 92R, between the first electrode 91G and the organic photoelectric conversion layer 92G, and between the first electrode 91B and the organic photoelectric conversion layer 92B. The electron transport layer is used to facilitate the provision of electrons generated in the organic photoelectric conversion layers 92R, 92G, and 92B to the first electrodes 91R, 91G, and 91B. For example, each electron transport layer is composed of titanium oxide or zinc oxide, etc. Each electron transport layer may be composed of a stacked titanium oxide film and a zinc oxide film. For example, the thickness of each electron transport layer is 0.1nm to 1000nm. Preferably, the thickness of each electron transport layer is 0.5nm to 300nm.

[0171] The organic photoelectric conversion layers 92R, 92G, and 92B absorb light in a selective band for photoelectric conversion, respectively, and transmit light in a band. Here, for the organic photoelectric conversion layer 92R, the light in the selective band is, for example, light in a band with a wavelength of 600 nm or more and less than 700 nm. For the organic photoelectric conversion layer 92G, the light in the selective band is, for example, light in a band with a wavelength of 500 nm or more and less than 600 nm. For the organic photoelectric conversion layer 92B, the light in the selective band is, for example, light in a band with a wavelength of 400 nm or more and less than 500 nm. The thickness of the organic photoelectric conversion layers 92R, 92G, and 92B is, for example, 25 nm or more and 400 nm or less, respectively. Preferably, the thickness of the organic photoelectric conversion layers 92R, 92G, and 92B is, respectively, 50 nm or more and 350 nm or less. More preferably, the thickness of the organic photoelectric conversion layers 92R, 92G, and 92B is, respectively, 150 nm or more and 300 nm or less.

[0172] The organic photoelectric conversion layers 92R, 92G, and 92B convert light energy into electrical energy, respectively. As with the photoelectric conversion layer 24, the organic photoelectric conversion layers 92R, 92G, and 92B are each composed of two or more organic materials used as p-type semiconductors or n-type semiconductors, respectively. In addition to p-type semiconductors and n-type semiconductors, the organic photoelectric conversion layers 92R, 92G, and 92B each include an organic material or a so-called dye material. The organic material or dye material performs photoelectric conversion on light in the above-mentioned predetermined band and transmits light in another band. For the organic photoelectric conversion layer 92R, examples of such materials include rhodamine, merocyanidin, and their derivatives. For the organic photoelectric conversion layer 92G, a compound represented by the above-mentioned general formula (1) (BODIPY dye) is mentioned. For the organic photoelectric conversion layer 92B, for example, coumarin, diazo compounds, cyanine dyes, or their derivatives, etc. are mentioned.

[0173] Examples of another organic material constituting each of the organic photoelectric conversion layers 92R, 92G, and 92B include fullerene or a fullerene derivative. The organic photoelectric conversion layers 92R, 92G, and 92B may each further include an organic material other than the above-described organic materials.

[0174] As in the above-described first embodiment, other layers may be provided between the organic photoelectric conversion layer 92R and the second electrode 93R, between the organic photoelectric conversion layer 92G and the second electrode 93G, and between the organic photoelectric conversion layer 92B and the second electrode 93B.

[0175] The second electrode 93R, the second electrode 93G, and the second electrode 93B are used to extract holes generated in the organic photoelectric conversion layer 92R, holes generated in the organic photoelectric conversion layer 92G, and holes generated in the organic photoelectric conversion layer 92G, respectively. For example, the holes extracted from the second electrodes 93R, 93G, and 93B, respectively, are discharged to a p-type semiconductor region (not shown) in the semiconductor substrate 80 through respective transmission paths (not shown).

[0176] For example, the second electrodes 93R, 93G and 93B are respectively made of conductive materials such as gold (Au), silver (Ag), copper (Cu) and aluminum (Al). Like the first electrodes 91R, 91G and 91B, the second electrodes 93R, 93G and 93B can be respectively made of transparent conductive materials. In the imaging element 10D, the holes extracted from these second electrodes 93R, 93G and 93B are discharged. For example, in the case where a plurality of imaging elements 10D are arranged in the imaging device 1 described below, the second electrodes 93R, 93G and 93B can also be set to be shared by each imaging element 10D (unit pixel P). The thickness of the second electrodes 93R, 93G and 93B is, for example, 0.5 nm or more and 100 nm or less.

[0177] The insulating layer 94 is used to insulate the second electrode 93R from the first electrode 91G. The insulating layer 95 is used to insulate the second electrode 93G from the first electrode 91B. For example, the insulating layers 94 and 95 are respectively made of metal oxide, metal sulfide, or organic matter. Examples of metal oxides include silicon oxide (SiO x ), aluminum oxide (AlO x )、ZrO x ), titanium oxide (TiO x ), zinc oxide (ZnO x ), tungsten oxide (WO x ), magnesium oxide (MgO x ), niobium oxide (NbO x ), tin oxide (SnO x ), gallium oxide (GaO x ) etc. Examples of metal sulfides include zinc sulfide (ZnS) and magnesium sulfide (MgS) etc. Preferably, the band gap of the constituent material of each of the insulating layers 94 and 95 is 3.0 eV or more. The thickness of each of the insulating layers 94 and 95 is, for example, 2 nm or more and 100 nm or less.

[0178] As described above, for example, by forming the organic photoelectric conversion layer 92G using the compound represented by the above-described general formula (1), effects similar to those of the above-described first embodiment can be obtained.

[0179] <4. Application Examples>

[0180] (Application example 1)

[0181] Fig.14 The overall structure of an imaging device (imaging device 1) using the imaging element 10A (or any one of the imaging elements 10B to 10D) described in the first to third embodiments for each pixel is shown. The imaging device 1 is a CMOS image sensor. On a semiconductor substrate 30, the imaging device 1 includes a pixel portion 1a as an imaging area and a peripheral circuit portion 130 in the peripheral area of ​​the pixel portion 1a. For example, the peripheral circuit portion 130 includes a row scanning portion 131, a horizontal selection portion 133, a column scanning portion 134, and a system control portion 132.

[0182] For example, the pixel section 1a includes a plurality of unit pixels P (corresponding to the image pickup element 10, respectively) arranged two-dimensionally in a matrix form. These unit pixels P are provided with pixel drive lines Lread (specifically, row selection lines and reset control lines). For example, each pixel row is provided with a pixel drive line Lread. Each pixel column is provided with a vertical signal line Lsig. The pixel drive line Lread transmits a drive signal for reading a signal from a pixel. One end of each pixel drive line Lread is connected to an output end of the row scanning section 131 corresponding to each row.

[0183] The row scanning section 131 is a pixel driving section that includes a shift register, an address decoder, and the like, and drives, for example, each unit pixel P in the pixel section 1a row by row. Signals output from each unit pixel P in a pixel row selectively scanned by the row scanning section 131 are supplied to the horizontal selection section 133 through each vertical signal line Lsig. The horizontal selection section 133 includes an amplifier and a horizontal selection switch, and the like, provided for each vertical signal line Lsig.

[0184] The column scanning section 134 includes a shift register, an address decoder, and the like, and sequentially drives each horizontal selection switch of the horizontal selection section 133 while scanning the horizontal selection switch. The selective scanning of the column scanning section 134 causes the signals of each pixel transmitted through each vertical signal line Lsig to be sequentially output to the horizontal signal line 135, and causes the signals to be transmitted to the outside of the semiconductor substrate 30 through the horizontal signal line 135.

[0185] The circuit section including the row scanning section 131, the horizontal selection section 133, the column scanning section 134 and the horizontal signal line 135 may be directly formed on the semiconductor substrate 30, or may be provided on an external control IC. In addition, the circuit section may also be formed on another substrate connected by a cable or the like.

[0186] The system control section 132 receives data such as a clock and instructions on an operation mode supplied from the outside of the semiconductor substrate 30, and outputs data such as internal information of the image pickup device 1. The system control section 132 also includes a timing generator for generating various timing signals, and the system control section 132 drives and controls peripheral circuits such as the row scanning section 131, the horizontal selection section 133, and the column scanning section 134 based on the various timing signals generated by the timing generator.

[0187] (Application Example 2)

[0188] The above-mentioned camera device 1 is applicable to any electronic device having a camera function, for example, including camera systems such as digital cameras and video cameras, and mobile phones having a camera function. As an example, Fig.15 The schematic structure of the electronic device 2 (camera) is shown. For example, the electronic device 2 is a video camera capable of taking still images or moving images. The electronic device 2 includes an image pickup device 1, an optical system (optical lens) 210, a shutter device 211, a driving unit 213 for driving the image pickup device 1 and the shutter device 211, and a signal processing unit 212.

[0189] The optical system 210 guides the image light (incident light) from the subject to the pixel section 1a of the image pickup device 1. The optical system 210 may include a plurality of optical lenses. The shutter device 211 controls the illumination period and the light shielding period of the image pickup device 1. The driving section 213 controls the transmission operation of the image pickup device 1 and the shutter operation of the shutter device 211. The signal processing section 212 performs various signal processing on the signal output from the image pickup device 1. The image signal Dout that has been subjected to the signal processing is stored in a storage medium such as a memory, or is output to a display, etc.

[0190] <5. Application Examples>

[0191] Furthermore, the above-described imaging device 1 is also applicable to the following electronic devices (capsule-type endoscope 10100 and mobile objects such as vehicles).

[0192] (Application example of in vivo information acquisition system)

[0193] In addition, the technology according to the present disclosure (the present technology) is applicable to various products. For example, the technology according to the present disclosure can be applied to an endoscopic surgery system.

[0194] Fig.16 : is a block diagram showing a schematic configuration example of a patient's in vivo information acquisition system using a capsule endoscope to which the technology according to the present disclosure (the present technology) can be applied.

[0195] The in-vivo information acquisition system 10001 includes a capsule endoscope 10100 and an external control device 10200 .

[0196] During the examination, the patient swallows the capsule endoscope 10100. The capsule endoscope 10100 has an imaging function and a wireless communication function, and sequentially captures images of the inside of an organ (hereinafter referred to as in-vivo images) at predetermined intervals while it moves inside an organ such as the stomach or intestine for a period of time by peristaltic motion until it is naturally discharged from the patient's body. Then, the capsule endoscope 10100 sequentially transmits information of the in-vivo images to the external control device 10200 outside the body by wireless transmission.

[0197] The external control device 10200 comprehensively controls the operation of the in-vivo information acquisition system 10001. Further, the external control device 10200 receives in-vivo image information transmitted thereto from the capsule endoscope 10100, and generates image data for displaying the in-vivo image on a display device (not shown) based on the received in-vivo image information.

[0198] In the in-vivo information acquiring system 10001, in this way, in-vivo images that image the state inside the body of the patient can be acquired at any time within the period after the capsule endoscope 10100 is swallowed until the capsule endoscope 10100 is excreted.

[0199] The configuration and functions of the capsule endoscope 10100 and the external control device 10200 are described in more detail below.

[0200] The capsule endoscope 10100 includes a capsule-shaped shell 10101, which contains a light source unit 10111, a camera unit 10112, an image processing unit 10113, a wireless communication unit 10114, a power supply unit 10115, a power supply unit 10116 and a control unit 10117.

[0201] The light source unit 10111 is composed of a light source, such as a light emitting diode (LED), and irradiates light onto the imaging field of the imaging unit 10112 .

[0202] The imaging unit 10112 is composed of an imaging element and an optical system including a plurality of lenses arranged in the previous stage of the imaging element. Reflected light (hereinafter referred to as observation light) of light irradiated on the body tissue as the observation target is converged by the optical system and introduced into the imaging element. In the imaging unit 10112, the incident observation light is photoelectrically converted by the imaging element, thereby generating an image signal corresponding to the observation light. The image signal generated by the imaging unit 10112 is provided to the image processing unit 10113.

[0203] The image processing unit 10113 is composed of a processor such as a central processing unit (CPU) or a graphics processing unit (GPU), and performs various signal processing on the image signal generated by the camera unit 10112. Therefore, the image processing unit 10113 provides the image signal on which the signal processing has been performed to the wireless communication unit 10114 as RAW data.

[0204] The wireless communication unit 10114 performs predetermined processing such as modulation processing on the image signal on which the signal processing has been performed by the image processing unit 10113, and transmits the obtained image signal to the external control device 10200 through the antenna 10114A. In addition, the wireless communication unit 10114 receives a control signal related to the drive control of the capsule endoscope 10100 from the external control device 10200 through the antenna 10114A. The wireless communication unit 10114 provides the control signal received from the external control device 10200 to the control unit 10117.

[0205] The power supply unit 10115 is composed of an antenna coil for power reception, a power regeneration circuit for regenerating power from current generated in the antenna coil, a voltage booster circuit, etc. The power supply unit 10115 generates power using the non-contact charging principle.

[0206] The power supply unit 10116 is composed of a secondary battery and stores the power generated by the power supply unit 10115. Fig.16 In order to avoid complicated illustration, arrow marks indicating the supply destination of power from the power supply unit 10116 and the like are omitted. However, the power stored in the power supply unit 10116 is supplied to the light source unit 10111, the camera unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the control unit 10117, and can be used to drive the light source unit 10111, the camera unit 10112, the image processing unit 10113, the wireless communication unit 10114, and the control unit 10117.

[0207] The control unit 10117 is composed of a processor such as a CPU, and appropriately controls the driving of the light source unit 10111, the camera unit 10112, the image processing unit 10113, the wireless communication unit 10114 and the power supply unit 10115 according to the control signal transmitted thereto from the external control device 10200.

[0208] The external control device 10200 is composed of a processor (such as a CPU or a GPU) or a microcomputer or a control board in which a processor and a storage element (such as a memory) are installed in a mixed manner. The external control device 10200 transmits a control signal to the control unit 10117 of the capsule endoscope 10100 through the antenna 10200A to control the operation of the capsule endoscope 10100. In the capsule endoscope 10100, for example, the light irradiation condition of the light source unit 10111 when observing the target can be changed according to the control signal from the external control device 10200. In addition, the imaging condition (for example, the frame rate or exposure value of the imaging unit 10112, etc.) can be changed according to the control signal from the external control device 10200. In addition, the content of the processing of the image processing unit 10113 or the condition for transmitting the image signal from the wireless communication unit 10114 (for example, the transmission interval or the number of transmitted images, etc.) can be changed according to the control signal from the external control device 10200.

[0209] In addition, the external control device 10200 performs various image processing on the image signal sent thereto from the capsule endoscope 10100 to generate image data for displaying the captured in-vivo image on the display device. As image processing, various signal processing may be performed, for example, development processing (demosaic processing), image quality improvement processing (bandwidth enhancement processing, super-resolution processing, noise reduction (NR: noise reduction) processing and / or image stabilization processing (image stabilization process)) and / or magnification processing (electronic zoom processing). The external control device 10200 controls the driving of the display device so that the display device displays the captured in-vivo image based on the generated image data. Alternatively, the external control device 10200 may also control a recording device (not shown) to record the generated image data, or control a printing device (not shown) to output the generated image data by printing.

[0210] An example of an in-vivo information acquisition system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit 10112 among the above components, for example. This improves the detection accuracy.

[0211] (Application example of endoscopic surgery system)

[0212] The technology according to the present disclosure (the present technology) is applicable to various products. For example, the technology according to the present disclosure can be applied to an endoscopic surgery system.

[0213] Fig.17 : is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to an embodiment of the present disclosure (the present technology) can be applied.

[0214] exist Fig.17 , a state is shown in which an operator (doctor) 11131 is using an endoscopic surgery system 11000 to perform surgery on a patient 11132 on a bed 11133. As shown in the figure, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 such as a pneumoperitoneum tube 11111 and an energy device 11112, a support arm device 11120 supporting the endoscope 11100 thereon, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0215] The endoscope 11100 includes a lens barrel 11101, a region of a predetermined length from the distal end of the lens barrel is inserted into the body cavity of a patient 11132, and a camera head 11102, the camera head being connected to the proximal end of the lens barrel 11101. In the example shown, the endoscope 11100 configured as a rigid endoscope having a rigid lens barrel 11101 is shown. However, the endoscope 11100 may also be configured as a flexible endoscope having a flexible lens barrel 11101.

[0216] The lens barrel 11101 has an opening at its distal end in which an objective lens is mounted. The light source device 11203 is connected to the endoscope 11100 so that the light generated by the light source device 11203 is introduced into the distal end of the lens barrel 11101 through a light guide extending into the interior of the lens barrel 11101, and irradiated onto an observation object in the body cavity of the patient 11132 through the objective lens. It should be noted that the endoscope 11100 may be a forward-looking endoscope or may be an oblique-looking endoscope or a side-looking endoscope.

[0217] The optical system and the imaging element are arranged inside the camera head 11102 so that the reflected light (observation light) from the observation object is gathered on the imaging element through the optical system. The observation light is photoelectrically converted by the imaging element to generate an electric signal corresponding to the observation light, that is, an image signal corresponding to the observation image. The image signal is transmitted to the CCU 11201 as raw (RAW) data.

[0218] The CCU 11201 includes a central processing unit (CPU), a graphics processing unit (GPU), etc., and centrally controls the operations of the endoscope 11100 and the display device 11202. Further, for example, the CCU 11201 receives an image signal from the camera head 11102, and performs various image processing such as development processing (demosaic processing) on ​​the image signal to display an image based on the image signal.

[0219] The display device 11202 displays thereon an image based on an image signal that has been image-processed by the CCU 11201 under the control of the CCU 11201 .

[0220] For example, the light source device 11203 includes a light source such as a light emitting diode (LED) and provides the endoscope 11100 with illumination light for imaging the surgical area.

[0221] The input device 11204 is an input interface of the endoscopic surgery system 11000. The user can input various information or instructions to the endoscopic surgery system 11000 through the input device 11204. For example, the user may input instructions to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) of the endoscope 11100.

[0222] The treatment tool control device 11205 controls the driving of the energy device 11112 to burn or cut tissue, seal blood vessels, etc. The pneumoperitoneum device 11206 supplies gas into the body cavity of the patient 11132 through the pneumoperitoneum tube 11111 to expand the body cavity in order to ensure the field of view of the endoscope 11100 and to ensure the working space of the operator. The recorder 11207 is a device capable of recording various information related to the operation. The printer 11208 is a device capable of printing various information related to the operation in various forms such as text, images, or graphics.

[0223] It should be noted that the light source device 11203 that provides irradiation light when imaging the surgical area to the endoscope 11100 can be composed of a white light source, for example, a white light source composed of an LED, a laser light source, or a combination thereof. In the case where the white light source is composed of a combination of red, green, and blue (RGB) laser light sources, since the output intensity and output timing of each color (each wavelength) can be controlled with high precision, the white balance of the captured image can be adjusted by the light source device 11203. Further, in this case, if the laser beams from the respective RGB laser light sources are irradiated on the observed object in a time-division manner, the drive of the imaging element of the camera head 11102 is controlled synchronously with the irradiation timing. Then, images corresponding to the R, G, and B colors, respectively, can also be captured in a time-division manner. According to this method, a color image can be obtained even if a color filter is not configured for the imaging element.

[0224] Furthermore, the drive of the light source device 11203 can be controlled so as to change the intensity of the light to be output at predetermined intervals. By controlling the drive of the imaging element of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and synthesize the images, it is possible to create an image with a high dynamic range without underexposed shadows and overexposed highlights.

[0225] Further, the light source device 11203 can be configured to provide light of a predetermined wavelength band corresponding to special light observation. For example, in special light observation, by utilizing the wavelength dependence of light absorption of body tissue, a narrow band of light is irradiated compared to the irradiation light (i.e., white light) during ordinary observation, and narrow band observation (narrow band imaging) is performed on predetermined tissues such as blood vessels in the surface layer of the mucosa with high contrast. Alternatively, in special light observation, fluorescence observation for obtaining an image from fluorescence generated by irradiating excitation light can be performed. In fluorescence observation, fluorescence observation (autofluorescence observation) of body tissue can be performed by irradiating excitation light on body tissue, or a fluorescent image can be obtained by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating excitation light corresponding to the fluorescence wavelength of the reagent on the body tissue. The light source device 11203 can be configured to provide such narrow band light and / or excitation light suitable for special light observation as described above.

[0226] Fig.18 It is shown Fig.17 A block diagram of an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0227] The camera head 11102 includes a lens unit 11401, an imaging unit 11402, a driving unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 includes a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected via a transmission cable 11400 so as to communicate with each other.

[0228] The lens unit 11401 is an optical system provided at a connection position with the lens barrel 11101. Observation light entering from the distal end of the lens barrel 11101 is guided to the camera head 11102 and introduced into the lens unit 11401. The lens unit 11401 is composed of a combination of a plurality of lenses including a zoom lens and a focus lens.

[0229] The number of imaging elements included in the imaging unit 11402 can be one (single-board type) or multiple (multi-board type). For example, when the imaging unit 11402 is configured as a multi-board type, image signals corresponding to each R, G and B are generated by the imaging element, and the image signals can be synthesized to obtain a color image. The imaging unit 11402 can also be configured to have a pair of imaging elements for acquiring a right eye image signal and a left eye image signal corresponding to a three-dimensional (3D) display. If a 3D display is performed, then the operator 11131 can more accurately grasp the depth of the living tissue in the surgical area. It should be noted that when the imaging unit 11402 is configured as a stereoscopic type, a plurality of lens unit 11401 systems are set corresponding to each imaging element.

[0230] Further, the camera unit 11402 may not necessarily be disposed on the camera head 11102. For example, the camera unit 11402 may be disposed just behind the objective lens inside the lens barrel 11101.

[0231] The driving unit 11403 is composed of an actuator, and moves the zoom lens and the focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. Therefore, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

[0232] The communication unit 11404 is constituted by a communication device for sending and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal acquired from the imaging unit 11402 to the CCU 11201 as RAW data via the transmission cable 11400.

[0233] In addition, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201, and supplies the control signal to the camera head control unit 11405. For example, the control signal includes information related to imaging conditions, such as information specifying a frame rate of an image to be captured, information specifying an exposure value when capturing an image, and / or information specifying a magnification and a focus of an image to be captured.

[0234] It should be noted that the imaging conditions such as the frame rate, exposure value, magnification or focus may be specified by the user or may be automatically set based on the acquired image signal by the control unit 11413 of the CCU 11201. In the latter case, an automatic exposure (AE) function, an automatic focus (AF) function and an automatic white balance (AWB) function are provided in the endoscope 11100.

[0235] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 through the communication unit 11404 .

[0236] The communication unit 11411 is constituted by a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted thereto from the camera head 11102 through the transmission cable 11400.

[0237] Further, the communication unit 11411 transmits a control signal for controlling the driving of the camera head 11102 to the camera head 11102. The image signal and the control signal may be transmitted through electrical communication, optical communication, or the like.

[0238] The image processing unit 11412 performs various image processing on the image signal in the form of RAW data transmitted thereto from the camera head 11102 .

[0239] The control unit 11413 performs various controls related to image capturing of the operation area, etc. through the endoscope 11100 and display of captured images obtained by image capturing of the operation area, etc. For example, the control unit 11413 creates a control signal for controlling the driving of the camera head 11102 .

[0240] Further, the control unit 11413 controls the display device 11202 to display a captured image in which the surgical area, etc., is imaged based on the image signal that has been image-processed by the image processing unit 11412. At this time, the control unit 11413 can use various image recognition technologies to recognize various objects in the captured image. For example, the control unit 11413 can recognize surgical tools such as surgical forceps, specific living areas, bleeding, fog when the energy device 11112 is used, etc. by detecting the shape, color, etc. of the edge of the object contained in the captured image. When the control unit 11413 controls the display device 11202 to display the captured image, it can use the recognition result to display various surgical support information in an overlapping manner with the image of the surgical area. In the case where the surgical support information is displayed in an overlapping manner and presented to the operator 11131, the burden of the operator 11131 can be reduced and the operator 11131 can reliably perform the operation.

[0241] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 to each other is an electric signal cable for electric signal communication, an optical fiber for optical communication, or a composite cable for electric communication and optical communication.

[0242] Here, although in the illustrated example, communication is performed by wired communication using the transmission cable 11400, communication between the camera head 11102 and the CCU 11201 may be performed by wireless communication.

[0243] An example of an endoscopic surgery system to which the technology according to the present disclosure can be applied is described above. The technology according to the present disclosure can be applied to the imaging unit 11402 among the above components. By applying the technology according to the present disclosure to the imaging unit 11402, the detection accuracy is improved.

[0244] Note that, although the description is given here using an endoscopic surgery system as an example, the technology according to the present disclosure can also be applied to, for example, a microsurgery system or the like.

[0245] (Application example of mobile object)

[0246] The technology according to the present disclosure is applicable to various products. For example, the technology according to the present disclosure can be implemented as a device installed on any type of mobile body, such as a car, an electric car, a hybrid car, a motorcycle, a bicycle, a personal mobile device, an airplane, a drone, a ship, a robot, a construction machine, or an agricultural machine (tractor).

[0247] Fig.19 : is a block diagram showing a schematic configuration example of a vehicle control system as an example of a moving body control system to which the technology according to the embodiment of the present disclosure can be applied.

[0248] The vehicle control system 12000 includes a plurality of electronic control units connected to each other via a communication network 12001. Fig.19 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. In addition, a microcomputer 12051, a sound / image output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown as the functional configuration of the integrated control unit 12050.

[0249] The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 serves as a control device for the following devices: a drive force generating device such as an internal combustion engine or a drive motor for generating a drive force for the vehicle; a drive force transmitting mechanism for transmitting the drive force to the wheels; a steering mechanism for adjusting the steering angle of the vehicle; and a braking device for generating a braking force for the vehicle, etc.

[0250] The body system control unit 12020 controls the operation of various devices provided to the vehicle body according to various programs. For example, the body system control unit 12020 is used as a control device for a keyless entry system, a smart key system, a power window device, or various lights such as a headlight, a taillight, a brake light, a turn signal light, or a fog light. In this case, radio waves transmitted from a portable device as a substitute for a key or signals of various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these input radio waves or signals, and controls the door lock device, the power window device, and lights of the vehicle.

[0251] The vehicle exterior information detection unit 12030 detects information about the exterior of the vehicle having the vehicle control system 12000. For example, the vehicle exterior information detection unit 12030 is connected to the camera unit 12031. The vehicle exterior information detection unit 12030 causes the camera unit 12031 to capture an image of the exterior of the vehicle and receives the captured image. Based on the received image, the vehicle exterior information detection unit 12030 can perform detection processing on objects such as people, vehicles, obstacles, signs, or symbols on the road surface, or detection processing of the distance to these objects.

[0252] The imaging unit 12031 is an optical sensor for receiving light and outputting an electrical signal corresponding to the amount of light received. The imaging unit 12031 may output the electrical signal as an image, or may output the electrical signal as information about the measured distance. In addition, the light received by the imaging unit 12031 may be visible light, or may be invisible light such as infrared rays.

[0253] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. For example, the in-vehicle information detection unit 12040 is connected to a driver state detection unit 12041 that detects the driver's state. The driver state detection unit 12041 includes, for example, a camera that takes a picture of the driver. Based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or the driver's concentration level, or can determine whether the driver is dozing off.

[0254] The microcomputer 12051 can calculate the control target value of the driving force generating device, the steering mechanism or the braking device based on the information about the inside or outside of the vehicle (the information is obtained by the outside information detection unit 12030 or the inside information detection unit 12040), and output the control command to the driving system control unit 12010. For example, the microcomputer 12051 can perform the coordinated control aimed at realizing the functions of the advanced driver assistance system (ADAS), which includes: collision avoidance or collision mitigation of the vehicle, following driving based on the vehicle-to-vehicle distance, vehicle speed maintenance driving, vehicle collision warning or vehicle lane departure warning, etc.

[0255] In addition, the microcomputer 12051 can perform collaborative control intended for autonomous driving, which enables the vehicle to drive autonomously by controlling a driving force generating device, a steering mechanism, or a braking device, etc. based on information about the interior or exterior of the vehicle (the information is obtained by the exterior information detection unit 12030 or the interior information detection unit 12040), without relying on the driver's operation.

[0256] In addition, the microcomputer 12051 can output a control command to the body system control unit 12020 based on information about the exterior of the vehicle, which is obtained by the exterior information detection unit 12030. For example, the microcomputer 12051 can perform cooperative control aimed at preventing glare by controlling the headlights to change from high beam to low beam according to the position of the preceding vehicle or the oncoming vehicle detected by the exterior information detection unit 12030.

[0257] The sound / image output unit 12052 transmits an output signal of at least one of sound and image to an output device that can visually or auditorily notify the vehicle's passengers or the outside of the vehicle of information. Fig.19 In the example of FIG. 1 , an audio speaker 12061, a display portion 12062, and an instrument panel 12063 are shown as output devices. For example, the display portion 12062 may include at least one of an in-vehicle display and a head-up display.

[0258] Fig. 20 12031 is a diagram showing an example of the installation position of the camera unit 12031.

[0259] exist Fig. 20 In the figure, the camera unit 12031 includes camera units 12101, 12102, 12103, 12104 and 12105.

[0260] The camera units 12101, 12102, 12103, 12104 and 12105 are, for example, arranged at positions on the front nose, side mirrors, rear bumper and rear door of the vehicle 12100 and at positions on the upper part of the windshield inside the vehicle. The camera unit 12101 arranged on the front nose and the camera unit 12105 arranged on the upper part of the windshield inside the vehicle mainly obtain images in front of the vehicle 12100. The camera units 12102 and 12103 arranged on the side mirrors mainly obtain images on the sides of the vehicle 12100. The camera unit 12104 arranged on the rear bumper or rear door mainly obtains images at the rear of the vehicle 12100. The camera unit 12105 arranged on the upper part of the windshield inside the vehicle is mainly used to detect vehicles in front, pedestrians, obstacles, signals, traffic signs or lanes, etc.

[0261] By the way, Fig. 20 An example of the photographing range of the camera units 12101 to 12104 is shown. The photographing range 12111 indicates the photographing range of the camera unit 12101 provided to the front nose. The photographing ranges 12112 and 12113 respectively indicate the photographing ranges of the camera units 12102 and 12103 provided to the side mirrors. The photographing range 12114 indicates the photographing range of the camera unit 12104 provided to the rear bumper or the rear door. For example, by superimposing the image data photographed by the camera units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above is obtained.

[0262] At least one of the imaging units 12101 to 12104 may have a function of obtaining distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera composed of a plurality of imaging elements, or may be an imaging element having pixels for phase difference detection.

[0263] For example, the microcomputer 12051 can determine the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the time change of the distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104, thereby extracting the nearest three-dimensional object as the leading vehicle, in particular, the three-dimensional object exists on the driving path of the vehicle 12100 and travels in substantially the same direction as the vehicle 12100 at a predetermined speed (e.g., equal to or greater than 0 km / h). In addition, the microcomputer 12051 can pre-set the inter-vehicle distance to be maintained in front of the leading vehicle, and perform automatic braking control (including follow-up stop control) or automatic acceleration control (including follow-up start control), etc. Therefore, cooperative control intended for automatic driving can be performed, which allows the vehicle to travel autonomously without relying on the driver's operation, etc.

[0264] For example, the microcomputer 12051 can classify the three-dimensional object data about the three-dimensional object into three-dimensional object data of two-wheeled vehicles, standard-sized vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on the distance information obtained from the camera units 12101 to 12104, extract the classified three-dimensional object data, and use the extracted three-dimensional object data to automatically avoid obstacles. For example, the microcomputer 12051 identifies obstacles around the vehicle 12100 as obstacles that can be visually identified by the driver of the vehicle 12100 and obstacles that are difficult for the driver of the vehicle 12100 to visually identify. Then, the microcomputer 12051 determines the collision risk representing the risk of collision with each obstacle. When the collision risk is equal to or higher than the set value and therefore there is a possibility of collision, the microcomputer 12051 outputs a warning to the driver via the audio speaker 12061 or the display unit 12062, and performs forced deceleration or evasive steering through the drive system control unit 12010. The microcomputer 12051 can thereby assist driving to avoid collision.

[0265] At least one of the camera units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 may identify a pedestrian by determining whether there is a pedestrian in the captured images of the camera units 12101 to 12104. For example, such identification of pedestrians is performed by a program that extracts feature points in the captured images of the camera units 12101 to 12104 that are infrared cameras and a program that determines whether it is a pedestrian by performing pattern matching processing on a series of feature points representing the outline of an object. When the microcomputer 12051 determines that there is a pedestrian in the captured images of the camera units 12101 to 12104 and thus identifies the pedestrian, the sound / image output unit 12052 controls the display unit 12062 so that a square contour line for emphasis is displayed in a manner superimposed on the identified pedestrian. The sound / image output unit 12052 may also control the display unit 12062 so that an icon or the like representing a pedestrian is displayed at a desired position.

[0266] <6. Example>

[0267] Next, the embodiments of the present disclosure will be described in detail. In Experiment 1, quantum chemical calculations were performed on BODIPY dye. In Experiment 2, the spectral characteristics of BODIPY dye were evaluated. In Experiment 3, a photoelectric conversion element containing BODIPY dye was produced, and its electrical characteristics were evaluated.

[0268] [Experiment 1]

[0269] As a compound (BODIPY dye) represented by the above-mentioned general formula (1), quantum chemical calculations were performed on the compounds represented by formulas (1-2) to (1-5). In addition, as a comparative example, quantum chemical calculations were performed on the compounds represented by the following formulas (2-1) to (2-3). First, the ground state S0 structure was optimized by using a quantum chemical calculation program (Gaussian). Subsequently, the structure of the obtained ground state S0 was used for TD-DFT (Time-Dependent Density Function Theory: time-dependent density functional theory) calculations. The ground state S0 structure optimization calculation was performed using B3LYP / 6-31G**, and TD-DFT calculations were performed using M062X / 6-31+G**. The transition state is defined as X. The excitation wavelength λ1 and oscillator strength f1 of the oscillation state of transition from the ground state S0 to the first excited state S1 (S0→S1) and the excitation wavelength λ2 and oscillator strength f2 of the oscillation state of transition from the ground state S0 to the second excited state S2 (S0→S2) were obtained. The second excited state S2 was set to an excited state in which the oscillator strength f2 was greater than 0.01 and the excitation wavelength λ2 was closest to the excitation wavelength λ1.

[0270] Table 1 lists the excitation wavelength λ1 and oscillator strength f1 of S0→S1, the excitation wavelength λ2 and oscillator strength f2 of S0→S2, and the difference (λ1-λ2) between the excitation wavelength λ1 and the excitation wavelength λ2 for each compound represented by formula (1-2) to formula (1-5) and formula (2-1) to formula (2-3). Fig.21 : is a characteristic diagram showing the absorption spectrum of the compound represented by formula (1-5) obtained by quantum science calculation. Fig. 22 : is a characteristic diagram showing the absorption spectrum of the compound represented by formula (2-1) obtained by quantum science calculation. Fig.23 : is a characteristic diagram showing the absorption spectrum of the compound represented by formula (2-2) obtained by quantum science calculation. Fig.24 : is a characteristic diagram showing the absorption spectrum of the compound represented by formula (1-2) obtained by quantum science calculation. Fig.25 : is a characteristic diagram showing the absorption spectrum of the compound represented by formula (1-3) obtained by quantum science calculation. Fig.26 : is a characteristic diagram showing the absorption spectrum of the compound represented by formula (1-4) obtained by quantum science calculation. Fig. 27 This is a characteristic diagram showing the absorption spectrum of the compound represented by formula (2-3) obtained by quantum science calculation. The vertical axis represents the oscillator strength (Oscillator Strength), and the horizontal axis represents the wavelength (nm).

[0271] [Chemical formula 8]

[0272]

[0273] [Table 1]

[0274]

[0275] Table 1 shows that each compound represented by formula (1-2) to formula (1-5) and formula (2-1) to formula (2-3) exhibits a large oscillator strength f1 of 0.45 to 0.59 when transitioning from the ground state S0 to the first excited state S1 (S0→S1). The absorption band of the excitation wavelength λ1 determines which wavelength band of the blue band, green band, and red band the compound represented by formula (1-2) to formula (1-5) and formula (2-1) to formula (2-3) absorbs.

[0276] It should be noted that the excitation wavelength λ1 of each of the compounds represented by formula (1-2) to formula (1-5) and formula (2-1) to formula (2-3) is 430nm to 462nm. This corresponds to the wavelength of blue, so it is considered that each compound is a dye that absorbs blue light. However, considering the results of Experiment 2 described below, it is considered reasonable that the compounds represented by formula (1-2) to formula (1-5) and formula (2-1) to formula (2-3) are all dyes that absorb green light.

[0277] For example, although the excitation wavelength λ1 of the compound represented by formula (1-5) is 444 nm, the maximum absorption wavelength of the thin film of the compound represented by formula (1-5) obtained from Experiment 2 is 548 nm. From this result, it can be seen that the excitation wavelength λ1 obtained by quantum chemical calculation and the value of the maximum absorption wavelength of the actually produced thin film are considered to have a deviation of about 100 nm. Taking into account this deviation of about 100 nm, the maximum absorption wavelength of the thin film of each compound represented by formula (1-2) to formula (1-5) and formula (2-1) to formula (2-3) is 534 nm to 566 nm. Therefore, these compounds are considered to be dyes that actually absorb green light.

[0278] Table 1 and Fig.21It is shown that the excitation wavelength λ1 of the oscillation state of the transition from the ground state S0 to the first excited state S1 (S0→S1) is the main absorption band of each compound represented by formula (1-2) to formula (1-5) and formula (2-1) to formula (2-3), and this absorption band is an absorption band that absorbs green light on the thin film actually prepared as described above. Compared with the transition from the ground state S0 to the first excited state S1 (S0→S1), in the compounds represented by formula (2-1) to formula (2-3), the excitation wavelength λ2 of the oscillation state of the transition from the ground state S0 to the second excited state S2 (S0→S2) is observed to be on the short wavelength side of 92nm to 106nm. This shows that the excitation wavelength λ2 of the oscillation state of the transition from the ground state S0 to the second excited state S2 (S0→S2) is considered to have absorption in the blue band. Therefore, the excitation wavelength λ2 of the oscillation state of transition from the ground state S0 to the second excited state S2 (S0→S2) is considered to be the cause of the reduction in color selectivity.

[0279] On the other hand, in the compounds represented by formula (1-2) to formula (1-5) containing hydrogen atoms at both the 1st position and the 7th position, the excitation wavelength λ2 of the oscillation state from the ground state S0 to the second excited state S2 (S0→S2) is observed to be on the short wavelength side of 113nm to 127nm, compared with the excitation wavelength λ1 of the oscillation state from the ground state S0 to the first excited state S1 (S0→S1). Therefore, for a compound whose excitation wavelength λ2 of the oscillation state from the ground state S0 to the second excited state S2 (S0→S2) is much shorter than the excitation wavelength λ1 of the oscillation state from the ground state S0 to the first excited state S1 (S0→S1), even in the case where the maximum absorption wavelength of the film is in the green band, the absorption wavelength from the ground state S0 to the second excited state S2 (S0→S2) can be closer to the short wavelength side than the blue band. In other words, as for the compounds represented by formula (1-2) to formula (1-5), the difference (λ1-λ2) between the excitation wavelength λ1 and the excitation wavelength λ2 of the compound represented by general formula (1) having hydrogen atoms at the 1st and 7th positions is obviously larger, so the absorption of the blue band can be reduced. By comparison Figure 21 to Figure 27 It can be seen that the compounds represented by formula (1-2) to formula (1-5) have reduced absorption in the blue region compared to the compounds represented by formula (2-1) to formula (2-3).

[0280] [Experiment 2]

[0281] The spectral characteristics of the compounds represented by Formula (1-5), Formula (2-1) and Formula (2-2) were evaluated using the following method. First, at 1×10 -5Under vacuum conditions of less than 1.5 Pa, the compounds represented by formula (1-5), formula (2-1) and formula (2-2) were respectively deposited on a glass substrate by a resistance heating method using an organic vapor deposition machine while rotating the substrate holder. The glass substrate was cleaned by UV / ozone treatment. The deposition was performed at a deposition rate of 0.1 nm / s and provided a film thickness of 50 nm. This was used as a sample for the single film spectral characteristics of the BODIPY dye.

[0282] The spectral characteristics were obtained by measuring the transmittance and reflectance of each wavelength in the band of 350nm to 700nm using a UV-visible spectrophotometer, and the light absorption rate (%) absorbed by each single film was obtained. The linear absorption coefficient (cm2) of each single film with respect to wavelength was evaluated based on the Lambert-Beer law by using the light absorption rate and film thickness of the single film as parameters. -1 ).

[0283] Fig.28 The absorption spectra of the compounds represented by formula (1-5), formula (2-1) and formula (2-2) are shown. Table 2 summarizes the maximum absorption wavelength (nm), maximum linear absorption coefficient (cm -1 ), linear absorption coefficient at 400nm, 420nm, 440nm, 450nm, 460nm, 600nm and 650nm wavelengths (cm -1 ) and the ratio of the linear absorption coefficient at these wavelengths to the maximum linear absorption coefficient.

[0284] [Table 2]

[0285]

[0286] Fig.28 Table 2 shows that the compounds represented by formula (1-5), formula (2-1) and formula (2-2) have a high 4 cm -1 The maximum linear absorption coefficient is above 2×10 4 cm -1 The maximum linear absorption coefficient is above 1.34 and is very suitable for materials that effectively absorb visible light. In addition, it is found that the compound represented by formula (1-5) has a low linear absorption coefficient at wavelengths of 350nm to 460nm and 600nm to 650nm, and can selectively absorb wavelengths of a predetermined band.

[0287] In addition, the maximum absorption wavelength of the compound represented by formula (1-5) is 548 nm, the maximum absorption wavelength of the compound represented by formula (2-1) is 584 nm, and the maximum absorption wavelength of the compound represented by formula (2-2) is 564 nm, which indicates that these compounds absorb green light.

[0288] In addition, the linear absorption coefficient of any compound represented by formula (1-5), formula (2-1) and formula (2-2) at wavelengths of 400nm, 420nm, 440nm, 450nm and 460nm is half of the maximum linear absorption coefficient or less, and the wavelengths of 400nm, 420nm, 440nm, 450nm and 460nm are respectively visible light wavelengths located on the short wavelength side compared to the green band. Wherein, the linear absorption coefficient of the compound represented by formula (1-5) is less than ten percent. In addition, the linear absorption coefficient of any compound represented by formula (1-5), formula (2-1) and formula (2-2) at wavelengths of 600nm and 650nm is half of the maximum linear absorption coefficient or less, and the wavelengths of 600nm and 650nm are respectively visible light wavelengths located on the long wavelength side compared to the green band. Wherein, the linear absorption coefficient of the compound represented by formula (1-5) is less than one percent. This indicates that the compound represented by the formula (1-5) absorbs wavelengths of a predetermined wavelength band more selectively than the compounds represented by the formula (2-1) and the formula (2-2).

[0289] The linear absorption coefficient of the compound represented by formula (1-5) in the blue band is reduced compared with the compounds represented by formula (2-1) and formula (2-2), which can be explained by the results obtained in Experiment 1. In other words, this is considered to be because the difference (S1-S2) between the first excited state S1 and the second excited state S2 of the compound having hydrogen atoms at the 1st position and the 7th position represented by the general formula (1) is large, and the absorption of the compound to the blue band is reduced.

[0290] Compared with the compounds represented by formula (2-1) and formula (2-2), the linear absorption coefficient of the compound represented by formula (1-5) for the red band is significantly reduced due to reduced cohesion.

[0291] [Experiment 3]

[0292] (Experimental Example 1)

[0293] First, a glass substrate provided with an ITO electrode (lower electrode) having a film thickness of 50 nm was cleaned by UV / ozone treatment. Subsequently, the glass substrate was moved to a vacuum evaporation device. -5 Under reduced pressure of less than 1.5 Pa, an organic layer is formed on a glass substrate using a resistance heating method while rotating a substrate holder. A film of the compound represented by the following formula (4) was formed with a thickness of 5 nm by evaporation at a rate of 1000 rpm. 60 Fullerene (Formula (5)), a compound represented by Formula (1-5) and BP-rBDT (Formula (6)) are used to form a photoelectric conversion layer. The evaporation rates are 0.025nm / sec (Formula (5)), 0.050nm / sec (Formula (1-5)) and 0.050nm / sec (Formula (6)), respectively, and a layer with a total thickness of 230nm is formed. Thus, a photoelectric conversion layer with a composition ratio of 20vol% (Formula (5)): 40vol% (Formula (1-5)): 40vol% (Formula (6)) is obtained. Next, A layer of the compound represented by the following formula (7) was formed with a thickness of 5 nm as a hole blocking layer at a deposition rate of . Subsequently, an AlSiCu film with a thickness of 100 nm was formed on the hole blocking layer by a vapor deposition method, and used as an upper electrode. As described above, a photoelectric conversion element having a photoelectric conversion area of ​​1 mm×1 mm was manufactured.

[0294] [Chemical formula 9]

[0295]

[0296] (Experimental Example 2)

[0297] A photoelectric conversion element was manufactured by a method similar to that of Experimental Example 1 except that the compound represented by the above formula (2-1) was used instead of the compound represented by the formula (1-5) used in Experimental Example 1 (Experimental Example 2).

[0298] (Experimental Example 3)

[0299] A photoelectric conversion element was manufactured by a method similar to that of Experimental Example 1 except that the compound represented by the above formula (2-2) was used instead of the compound represented by the formula (1-5) used in Experimental Example 1 (Experimental Example 3).

[0300] The external quantum efficiency (EQE) and dark current characteristics of each of the photoelectric conversion elements manufactured in Experimental Examples 1 to 3 were evaluated by using the following methods.

[0301] The EQE and dark current characteristics were evaluated by using a semiconductor parameter analyzer. Specifically, the amount of light irradiated from the light source to the photoelectric conversion element through the filter was measured at 1.62 μW / cm 2 The current value (bright current value) obtained when the bias voltage applied between the electrodes is -2.6 V and the light amount irradiating the photoelectric conversion element is 0 μW / cm 2The current value (dark current value) obtained in the case of . EQE and dark current characteristics are calculated based on these values. As the wavelength of light irradiating the element, a wavelength corresponding to the maximum absorption wavelength in the visible light range of each organic photoelectric conversion layer is selected. As the irradiation wavelength of light, 530nm, 560nm and 560nm are selected in the order of Experimental Example 1, Experimental Example 2 and Experimental Example 3.

[0302] [Table 3]

[0303]

[0304] Table 3 summarizes the configurations of the photoelectric conversion layers, EQE, and dark current characteristics in Experimental Examples 1 to 3. It should be noted that the EQE described in Table 3 is a relative value in the case where Experimental Example 2 is used as a reference (1.0).

[0305] Table 3 shows that Experimental Example 1 using the compound represented by formula (1-5) has higher EQE and more excellent dark current characteristics compared with Experimental Examples 2 and 3. This shows that good EQE and dark current characteristics can be obtained by using a compound represented by general formula (1) having hydrogen atoms at the 1st position and the 7th position. In addition, the results of Experiment 2 clearly show that the photoelectric conversion layer used in Experimental Example 1 is capable of selectively absorbing wavelengths of a predetermined band. As described above, it was found that by including a photoelectric conversion layer of a compound represented by general formula (1) having hydrogen atoms at the 1st position and the 7th position, an imaging element having better electrical characteristics and better color selectivity than ordinary imaging elements can be manufactured.

[0306] Although the first to third embodiments, examples and applicable examples have been described, the content of the present disclosure is not limited to the above-mentioned embodiments, etc. Various modifications can be made. In addition, the number of these organic photoelectric conversion parts and inorganic photoelectric conversion parts or their ratios are not limited. Color signals of multiple colors can be obtained using only organic photoelectric conversion parts.

[0307] In the above embodiment, the example in which the plurality of electrodes included in the lower electrode 21 include two electrodes of the readout electrode 21A and the accumulation electrode 21B has been described. However, three or four or more electrodes including a transfer electrode or a discharge electrode may be provided.

[0308] It should be noted that the effects described here are merely examples and are not restrictive. In addition, there may be other effects.

[0309] It should be noted that the present technology may also have the following configuration. According to the present technology having the following configuration, the organic layer is formed using the compound represented by the above general formula (1). Therefore, the selectivity of the wavelength detected by the organic layer can be increased, and the spectral characteristics can be improved.

[0310] [1] An imaging device comprising:

[0311] a first electrode;

[0312] a second electrode disposed opposite to the first electrode; and

[0313] An organic layer is provided between the first electrode and the second electrode, wherein the organic layer comprises a compound represented by the following general formula (1):

[0314] [Chemical formula 1]

[0315]

[0316] (Wherein, R1 and R4 each independently represent a hydrogen atom or a deuterium atom; R2 and R3 each independently represent an alkyl group, a cycloalkyl group, an alkoxy group or an aryl ether group; R5 and R6 each independently represent a halogen atom, a hydrogen atom or an alkyl group; R7 represents an aryl group, a heteroaryl group or an alkenyl group; M represents boron or an m-valent metal atom, and includes at least one of germanium, beryllium, magnesium, aluminum, chromium, iron, nickel, copper, zinc and platinum; L represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group; n represents an integer of 1 or more and 6 or less, and when n-1 is 2 or more, L each independently represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group.)

[0317] [2] The imaging element according to [1], wherein the organic layer detects a wavelength in any one of an infrared region and a visible light region.

[0318] [3] The imaging element according to [1] or [2], wherein the organic layer detects a wavelength in any one of a red wavelength band, a green wavelength band, and a blue wavelength band.

[0319] [4] The imaging element according to any one of [1] to [3], wherein the organic layer detects a wavelength in a green band.

[0320] [5] The imaging element according to any one of [1] to [4], wherein:

[0321] The organic layer includes a photoelectric conversion layer, and

[0322] The photoelectric conversion layer contains the compound represented by the general formula (1).

[0323] [6] The imaging element according to [5], wherein the photoelectric conversion layer contains two or more organic semiconductor materials.

[0324] [7] The imaging element according to any one of [1] to [6], wherein the compound represented by the general formula (1) includes an organic semiconductor material having electron acceptability.

[0325] [8] The imaging element according to any one of [1] to [7], wherein M of the compound represented by the general formula (1) represents boron, and L represents a fluorine atom or a fluorine-containing aromatic group.

[0326] [9] The imaging element according to any one of [1] to [8], wherein R7 of the compound represented by the general formula (1) represents an aryl group or a heteroaryl group.

[0327]

[10] The imaging element according to any one of [1] to [8], wherein R7 of the compound represented by the general formula (1) represents a heteroaryl group and contains a fluorine atom.

[0328]

[11] The imaging device according to any one of [1] to

[10] , wherein:

[0329] The organic layer includes a plurality of layers, and

[0330] At least one layer among the plurality of layers contains the compound represented by the general formula (1).

[0331]

[12] A camera device comprising:

[0332] Pixels, each of which includes one or more organic photoelectric conversion units, wherein

[0333] The organic photoelectric conversion parts respectively include

[0334] a first electrode;

[0335] a second electrode disposed opposite to the first electrode; and

[0336] An organic layer is provided between the first electrode and the second electrode, wherein the organic layer comprises a compound represented by the following general formula (1):

[0337] [Chemical formula 2]

[0338]

[0339] (Wherein, R1 and R4 each independently represent a hydrogen atom or a deuterium atom; R2 and R3 each independently represent an alkyl group, a cycloalkyl group, an alkoxy group or an aryl ether group; R5 and R6 each independently represent a halogen atom, a hydrogen atom or an alkyl group; R7 represents an aryl group, a heteroaryl group or an alkenyl group; M represents boron or an m-valent metal atom, and includes at least one of germanium, beryllium, magnesium, aluminum, chromium, iron, nickel, copper, zinc and platinum; L represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group; n represents an integer of 1 or more and 6 or less, and when n-1 is 2 or more, L each independently represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group.)

[0340]

[13] An imaging device according to

[12] , wherein, in each pixel, one or more of the organic photoelectric conversion units and one or more inorganic photoelectric conversion units are stacked, and the one or more inorganic photoelectric conversion units perform photoelectric conversion in a band different from that of the organic photoelectric conversion unit.

[0341]

[14] The imaging device according to

[13] , wherein the organic photoelectric conversion unit having an organic layer containing the compound represented by the general formula (1) is provided at a position closer to incident light than the other organic photoelectric conversion units and the inorganic photoelectric conversion unit.

[0342]

[15] The imaging device according to

[13] or

[14] , wherein:

[0343] The one or more inorganic photoelectric conversion parts are formed to be buried in the semiconductor substrate, and

[0344] The one or more organic photoelectric conversion sections are formed on the first surface side of the semiconductor substrate.

[0345]

[16] The imaging device according to

[15] , wherein a plurality of wiring layers are formed on the second surface side of the semiconductor substrate.

[0346]

[17] The imaging device according to any one of

[13] to

[16] , wherein:

[0347] Each of the organic photoelectric conversion units performs photoelectric conversion in the green band, and

[0348] An inorganic photoelectric conversion unit that performs photoelectric conversion in a blue wavelength band and an inorganic photoelectric conversion unit that performs photoelectric conversion in a red wavelength band are stacked in the semiconductor substrate.

[0349]

[18] An imaging device according to any one of

[12] to

[17] , wherein a plurality of the organic photoelectric conversion units are stacked in each pixel, and the plurality of the organic photoelectric conversion units perform photoelectric conversion in wavelength ranges different from each other.

[0350] This application claims the benefit of Japanese Patent Application No. 2019-139917 filed with the Japan Patent Office on July 30, 2019, the entire contents of which are hereby incorporated by reference into this application.

[0351] Those skilled in the art should understand that various modifications, combinations, sub-combinations and alterations may be made according to design requirements and other factors, as long as these modifications, combinations, sub-combinations and alterations are within the scope of the appended claims or the equivalents thereof.

Claims

1. A camera device, comprising: Pixels, each of which includes one or more organic photoelectric conversion units, wherein The organic photoelectric conversion parts respectively include a first electrode; a second electrode disposed opposite to the first electrode; and An organic layer is provided between the first electrode and the second electrode, wherein the organic layer comprises a compound represented by the following general formula (1): wherein R1 and R4 each independently represent a hydrogen atom or a deuterium atom; R2 and R3 each independently represent an alkyl group, a cycloalkyl group, an alkoxy group or an aryl ether group; R5 and R6 each independently represent a halogen atom, a hydrogen atom or an alkyl group; R7 represents an aryl group, a heteroaryl group or an alkenyl group; M represents boron or an m-valent metal atom, and includes at least one of germanium, beryllium, magnesium, aluminum, chromium, iron, nickel, copper, zinc and platinum; L represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group; n represents an integer of 1 to 6, and when n-1 is 2 or more, L each independently represents a halogen atom, a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, wherein, in each pixel, one or more of the organic photoelectric conversion units and one or more of the inorganic photoelectric conversion units are stacked, and the one or more inorganic photoelectric conversion units respectively perform photoelectric conversion in a wavelength band different from that of the organic photoelectric conversion unit, and The organic photoelectric conversion unit having an organic layer containing the compound represented by the general formula (1) is provided at a position closer to incident light than the other organic photoelectric conversion units and the inorganic photoelectric conversion unit.

2. The imaging device according to claim 1, wherein: The one or more inorganic photoelectric conversion parts are formed to be buried in the semiconductor substrate, and The one or more organic photoelectric conversion sections are formed on the first surface side of the semiconductor substrate.

3. The imaging device according to claim 2, wherein: A plurality of wiring layers are formed on the second surface side of the semiconductor substrate.

4. The imaging device according to claim 2, wherein: Each of the organic photoelectric conversion units performs photoelectric conversion in the green band, and An inorganic photoelectric conversion unit that performs photoelectric conversion in a blue wavelength band and an inorganic photoelectric conversion unit that performs photoelectric conversion in a red wavelength band are stacked in the semiconductor substrate.

5. The imaging device according to any one of claims 1 to 4, wherein: A plurality of the organic photoelectric conversion sections are stacked in each pixel, and the plurality of organic photoelectric conversion sections perform photoelectric conversion in wavelength ranges different from each other.

Images