Photoelectric conversion elements, sensors, and electronic devices

Abstract

To provide a photoelectric conversion element, a sensor, and an electronic device, in which the charge extraction characteristic is improved by reducing the residual charges.SOLUTION: A photoelectric conversion element includes a first electrode, a second electrode, and a photoelectric conversion layer existing between the first electrode and the second electrode. The photoelectric conversion layer includes a mixture of a first material, a second material, and a third material that are different from each other. The first material and the third material are light-absorbing materials with the maximum absorption wavelength in a first wavelength region corresponding to at least one of a blue wavelength region, a green wavelength region, a red wavelength region, and an infrared wavelength region. The dipolar moment of the third material is 5.5 Debye or more. The third material is contained by 30 vol% or less relative to the total volume of the first material and the third material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a photoelectric conversion element, a sensor, and an electronic device. [Background technology]

[0002] A photoelectric conversion element is an element that receives light and converts it into an electrical signal, and includes photodiodes and phototransistors, and is applied to sensors or photodetectors.

[0003] Sensors are increasingly required to have higher resolution, which is leading to smaller pixel sizes. In the case of silicon photodiodes, which are currently the main type of sensor used, the absorption area decreases as the pixel size decreases, resulting in a decrease in sensitivity. As a result, research is being conducted on organic materials to replace silicon.

[0004] Organic materials have a high absorption coefficient and can selectively absorb light in specific wavelength ranges depending on their molecular structure, making them advantageous for high integration as they can simultaneously replace photodiodes and color filters.

[0005] However, organic materials can exhibit different properties from silicon due to their high binding energy and recombination behavior, making it difficult to accurately predict their properties and easily control the physical properties required for photoelectric conversion elements. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-140677 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention has been made in view of the above-mentioned conventional problems, and the object of the present invention is to provide a photoelectric conversion element that reduces residual charge and improves charge extraction characteristics, a sensor including a photoelectric conversion element, and an electronic device including a photoelectric conversion element or a sensor. [Means for solving the problem]

[0008] To achieve the above objective, a photoelectric conversion element according to one aspect of the present invention comprises a first electrode, a second electrode, and a photoelectric conversion layer located between the first electrode and the second electrode, wherein the photoelectric conversion layer comprises a mixture of different first, second, and third substances, the first and third substances being absorbent materials having a maximum absorption wavelength in one of the first wavelength regions among the blue wavelength region, the green wavelength region, the red wavelength region, and the infrared wavelength region, the dipole moment of the third substance being 5.5 Debye or more, and the third substance being present in an amount of 30% or less by volume relative to the total volume of the first and third substances.

[0009] The first and third substances are p-type substances, and the second substance may be an n-type substance. The HOMO energy level of the third substance may be deeper than or shallower than the HOMO energy level of the first substance, within a range of 0.3 eV or less. The HOMO energy level of the third substance may be 4.7 eV to 6.2 eV, and the HOMO energy level of the first substance may be 5.0 eV to 5.8 eV. The HOMO energy level of the third substance is 5.1 eV to 6.0 eV, and the HOMO energy level of the first substance may be 5.0 eV to 5.8 eV. The third substance may be present in an amount of 1 to 10% by volume relative to the total volume of the first and third substances. The photoelectric conversion layer may be a three-component system consisting of the first substance, the second substance, and the third substance.

[0010] The third substance can be represented by the following chemical formula 1-1. [ka] In the above Chemical Formula 1-1, X 1 is O, S, Se, Te, SO, SO2, SiR a R b , or GeR c R d and Ar 2 is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 30 carbon atoms, or two or more condensed rings selected therefrom, Ar 1b and Ar 2b each independently is hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, Ar 1b and Ar 2b each independently exists or combines with each other to form a condensed ring, R 4 ~R 6 and R a ~R d each independently is hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, halogen, or a cyano group.

[0011] The first substance may be represented by the following Chemical Formula A-1.

Chemical Formula

[0012] A sensor according to one aspect of the present invention, made to achieve the above objective, includes the photoelectric conversion element.

[0013] An electronic device according to one aspect of the present invention, made to achieve the above objective, includes the photoelectric conversion element or the sensor. [Effects of the Invention]

[0014] The photoelectric conversion element of the present invention can reduce residual charge and improve charge extraction characteristics. [Brief explanation of the drawing]

[0015] [Figure 1]This is a cross-sectional view showing an example of a photoelectric conversion element according to one embodiment. [Figure 2] This is a cross-sectional view showing another example of a photoelectric conversion element according to one embodiment. [Figure 3] This is a cross-sectional view showing an example of an image sensor according to one embodiment. [Figure 4] This is a plan view showing an example of an image sensor according to one embodiment. [Figure 5] Figure 4 is a cross-sectional view showing an example of an image sensor. [Figure 6] Figure 4 is a cross-sectional view showing another example of an image sensor. [Figure 7] This is a plan view showing another example of an image sensor according to one embodiment. [Figure 8] Figure 7 is a cross-sectional view showing an example of an image sensor. [Figure 9] This is a plan view showing another example of an image sensor according to one embodiment. [Figure 10] Figure 9 is a cross-sectional view showing an example of an image sensor. [Figure 11] This is a cross-sectional view showing an example of an image sensor according to one embodiment. [Figure 12] This is a cross-sectional view showing another example of an image sensor according to one embodiment. [Figure 13] This is a schematic diagram of an electronic device according to one embodiment. [Figure 14] This graph shows the change in the distribution of HOMO energy levels of the first substance. [Figure 15] This graph shows the change in residual charge in response to the change in the distribution of the HOMO energy levels of the first substance. [Figure 16] This graph shows the change in residual charge in response to the change in the distribution of the HOMO energy levels of the first substance. [Modes for carrying out the invention]

[0016] Hereinafter, specific examples of embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, the structures actually applied can be realized in various different forms and are not limited to the embodiments described herein.

[0017] In the drawings, the thickness is enlarged to clearly represent the various layers and regions.

[0018] When a part of a layer, membrane, region, or plate is said to be "on top of" another part, this includes not only when it is "directly above" the other part, but also when there is another part in between. Conversely, when one part is said to be "directly above" another part, it means that there is no other part in between.

[0019] Unless otherwise defined below, "substitution" means that a hydrogen atom in a compound is replaced by a halogen atom, hydroxyl group, alkoxy group, nitro group, cyano group, amino group, azide group, amidino group, hydrazino group, hydrazono group, carbonyl group, carbamoyl group, thiol group, ester group, carboxyl group or its salt, sulfonic acid group or its salt, phosphoric acid or its salt, silyl group, C1-C20 alkyl group, C2-C20 alkenyl group, C2-C20 alkynyl group, or C6 This means that the substituents are selected from aryl groups with up to 30 carbon atoms, arylalkyl groups with 7 to 30 carbon atoms, alkoxy groups with 1 to 30 carbon atoms, heteroalkyl groups with 1 to 20 carbon atoms, heteroaryl groups with 3 to 20 carbon atoms, heteroarylalkyl groups with 3 to 20 carbon atoms, cycloalkyl groups with 3 to 30 carbon atoms, cycloalkenyl groups with 3 to 15 carbon atoms, cycloalkynyl groups with 6 to 15 carbon atoms, heterocycloalkyl groups with 3 to 30 carbon atoms, and combinations thereof.

[0020] Unless otherwise defined below, "hetero" means a material containing one to four heteroatoms selected from N, O, S, Se, Te, Si, and P.

[0021] In the following, "combination" includes mixed and layered structures of two or more components.

[0022] Unless otherwise defined below, the energy level is either the highest occupied molecular orbital (HOMO) energy level or the lowest unoccupied molecular orbital (LUMO) energy level.

[0023] Unless otherwise defined below, the work function or energy level is expressed as an absolute value relative to the vacuum level. Furthermore, a deep, high, or large work function or energy level means that the absolute value is large relative to the vacuum level of "0 eV," while a shallow, low, or small work function or energy level means that the absolute value is small relative to the vacuum level of "0 eV."

[0024] Unless otherwise defined below, the work function and energy levels are values ​​calculated using Turbomole with the B3LYP / def2-SVP basis set.

[0025] A photoelectric conversion element according to one embodiment of the present invention will be described below with reference to the drawings.

[0026] Figure 1 is a cross-sectional view showing an example of a photoelectric conversion element according to one embodiment.

[0027] Referring to Figure 1, the photoelectric conversion element 100 according to this embodiment includes a first electrode 10, a second electrode 20, and a photoelectric conversion layer 30.

[0028] A substrate (not shown) is positioned on either the first electrode 10 side or the second electrode 20 side. The substrate may be made of an inorganic material such as glass; a silicon wafer; or an organic material such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyethersulfone, or a combination thereof. The substrate may be omitted.

[0029] Either the first electrode 10 or the second electrode 20 is the anode, and the other is the cathode. For example, the first electrode 10 is the anode and the second electrode 20 is the cathode. For example, the first electrode 10 is the cathode and the second electrode 20 is the anode.

[0030] At least one of the first electrode 10 and the second electrode 20 is a transparent electrode. Here, the transparent electrode has a high transmittance of about 80% or more. The transparent electrode includes at least one of, for example, an oxide conductor, a carbon conductor, and a metal thin film. The oxide conductor is one or more selected from, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc tin oxide (ZTO), aluminum tin oxide (AlTO), and aluminum zinc oxide (AZO). The carbon conductor is one or more selected from graphene and carbon nanomaterials. The metal thin film is a very thin film containing aluminum (Al), magnesium (Mg), silver (Ag), gold (Au), alloys thereof, or combinations thereof.

[0031] Either the first electrode 10 or the second electrode 20 is a reflective electrode. The reflective electrode has, for example, a light transmittance of less than about 10% or a reflectance of about 5% or more. The reflective electrode contains a reflective conductor such as a metal, for example, aluminum (Al), silver (Ag), gold (Au), or an alloy thereof.

[0032] For example, the first electrode 10 and the second electrode 20 are both transparent electrodes, and one of the first electrode 10 and the second electrode 20 is a light-receiving electrode.

[0033] For example, the first electrode 10 is a transparent electrode, the second electrode 20 is a reflective electrode, and the first electrode 10 is a photodetector.

[0034] For example, the first electrode 10 is a reflective electrode, the second electrode 20 is a transparent electrode, and the second electrode 20 is a photoreceiving electrode.

[0035] The photoelectric conversion layer 30 is positioned between the first electrode 10 and the second electrode 20.

[0036] The photoelectric conversion layer 30 absorbs light in at least a portion of wavelength ranges and converts it into electrical signals, for example, converting a portion of light in the blue wavelength range (hereinafter referred to as "blue light"), the green wavelength range (hereinafter referred to as "green light"), the red wavelength range (hereinafter referred to as "red light"), and the infrared wavelength range (hereinafter referred to as "infrared light") into electrical signals.

[0037] As an example, the photoelectric conversion layer 30 selectively absorbs one of the following: blue light, green light, red light, and infrared light, and converts it into an electrical signal. Selective absorption of one of the following: blue light, green light, red light, and infrared light means that the maximum absorption wavelength (λ) of the absorption spectrum is selected. max ) is located in one of the following wavelength regions: approximately 380 nm to less than 500 nm, approximately 500 nm to 600 nm, approximately 600 nm to 700 nm, and approximately 700 nm to 3,000 nm, and the absorbance spectrum in that wavelength region is significantly higher than the absorbance spectrum in other wavelength regions. Significantly higher means that, for example, approximately 70% to 100%, approximately 75% to 100%, approximately 80% to 100%, approximately 85% to 100%, approximately 90% to 100%, or approximately 95% to 100% of the total area of ​​the absorbance spectrum belongs to that wavelength region.

[0038] The photoelectric conversion layer 30 includes a first material and a second material that form a pn junction. The first and second materials receive light from the outside and generate excitons, which are then separated into holes and electrons. For example, the first material is a p-type material and the second material is an n-type material.

[0039] For example, the first and second substances are each light-absorbing substances, and for instance, at least one of the first and second substances is an organic light-absorbing substance. For example, at least one of the first and second substances is a wavelength-selective light-absorbing substance that selectively absorbs light in a predetermined wavelength range, and for instance, at least one of the first and second substances is a wavelength-selective organic light-absorbing substance. The absorption spectra of the first and second substances are such that the maximum absorption wavelength (λ) is the same or different wavelength range for each substance. max ) has.

[0040] For example, the absorption spectra of substance 1 and substance 2 independently selectively absorb one of the following: blue light, green light, red light, and infrared light, and the maximum absorption wavelength (λ) of the absorption spectrum of substance 1 or substance 2 is determined. max ) exists in one of the following wavelength regions: approximately 380 nm to less than 500 nm, approximately 500 nm to 600 nm, approximately 600 nm to 700 nm, and approximately 700 nm to 3,000 nm.

[0041] For example, substance 1 and / or substance 2 are organic substances.

[0042] For example, substance 1 and / or substance 2 are low-molecular-weight compounds.

[0043] For example, the first substance and / or the second substance are vapor-depositing compounds.

[0044] As an example, the first substance is an organic material having a core structure that includes an electron-donating moiety (EDM), a π-conjugated linking moiety, and an electron-accepting moiety (EAM).

[0045] The first substance is, for example, represented by the following chemical formula A, but is not limited to this.

[0046] [Chemical formula A] EDM1-HA1-EAM1

[0047] In the above chemical formula A, HA1 is a π-conjugated moiety, which is a substituted or unsubstituted heterocyclic group having 2 to 30 carbon atoms. EDM1 is an electronic child and a moiety, EAM1 is an electron-accepting moiety.

[0048] For example, the first substance represented by chemical formula A may be represented by chemical formula A-1 below, but is not limited to this.

[0049] [ka]

[0050] In the above chemical formula A-1, X 1 is O, S, Se, Te, SO, SO2, SiR a R b , or GeR c R d And, Ar 1 This is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 30 carbon atoms, or two or more fused rings selected from these. Ar 1a and Ar 2a Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C3-C30 heteroaryl group. Ar 1a and Ar 2a These elements either exist independently or combine with each other to form a fused ring. R 1 ~R 3 and R a ~R dEach of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a halogen, or a cyano group.

[0051] As an example, Ar in chemical formula A-1 1a and Ar 2a Each of these independently comprises a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenantrenyl group, a substituted or unsubstituted pyridinyl group, a substituted or unsubstituted pyridazinyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted isoquinolinyl group, and a substituted or unsubstituted naphthyl group. These are naphthyridinyl groups, substituted or unsubstituted cinnolinyl groups, substituted or unsubstituted quinazolinyl groups, substituted or unsubstituted phthalazinyl groups, substituted or unsubstituted benzotriazinyl groups, substituted or unsubstituted pyridopyrazinyl groups, substituted or unsubstituted pyridopyrimidinyl groups, or substituted or unsubstituted pyridopyridazinyl groups.

[0052] As an example, Ar in chemical formula A-1 1a and Ar 2a They condense with each other to form a ring, Ar 1a and Ar 2a Examples include single bonds, -O-, -S-, -Se-, -Te-, -N=, -NR e -,-(CR f R g ) n2-(n2 is 1 or 2), -SiR h R i -, -GeR j R k -,-(C(R l )=C(R m ))-, or SnR n R o They are connected to form a ring. Here R e ~R o Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a halogen, or a cyano group, R f and R g , R h and R i , R j and R k , R l and R m , and R n and R o These elements either exist independently or are connected to each other to form a ring.

[0053] For example, the first substance represented by chemical formula A-1 may be represented by chemical formulas A-2 to A-5 below, but is not limited to these.

[0054] [ka]

[0055] Among the above chemical formulas A-2 to A-5, X 1 and R 1 ~R 3 As stated above, Ar 3 This is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 30 carbon atoms, or two or more fused rings selected from these. G represents single bonds, -O-, -S-, -Se-, -Te-, -N=, -NR e -,-(CRf R g ) n2 -(where n2 is 1 or 2), -SiR h R i -, -GeR j R k -, -(C(R l )=C(R m ))-, or SnR n R o and where R e ~R o are each independently hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a halogen, or a cyano group, and R f and R g , R h and R i , R j and R k , R l and R m , and R n and R o each independently exist or are linked to each other to form a ring, Y 2 is O, S, Se, Te, or C(R p )(CN) (where R p is hydrogen, a cyano group (-CN) or an alkyl group having 1 to 10 carbon atoms), R 6a ~R 6e , R 7a ~R 7e , R 16 and R 17 are each independently hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a halogen, or a cyano group, R 6a ~R 6e each independently exist or two adjacent ones of them are linked to each other to form a fused ring, R 7a~R 7e These elements either exist independently or two adjacent elements are linked together to form a fused ring.

[0056] As an example, Ar in chemical formula A-2 or A-4 3 is benzene, naphthalene, anthracene, thiophene, selenofen, telolofen, pyridine, pyrimidine, or two or more condensed rings selected from these.

[0057] The second substance includes, for example, organic substances, inorganic substances, and / or organic-inorganic substances, and is not limited to, for example, thiophene or thiophene derivatives, fullerene or fullerene derivatives.

[0058] The photoelectric conversion layer 30 further contains a third substance. The third substance is different from the first and second substances and is a dopant that modifies the physical properties of the first and / or second substances within the photoelectric conversion layer 30.

[0059] The third substance is mixed with the first and second substances and positioned to be in contact with the first and / or second substances at the atomic scale, thereby altering the morphology of the first and / or second substances or the molecular conformation of the first and second substances, which form a pn junction. As a result, the diversity of morphology and molecular conformation of the photoelectric conversion layer 30 containing the first, second, and third substances differs from the diversity of morphology and molecular conformation of the thin film made up of the first and second substances.

[0060] According to quantum calculations based on such morphology, a third substance having a high dipole moment deforms the energy level distribution of the first and / or second substance. For example, a third substance having a high dipole moment deforms the HOMO energy level distribution or LUMO energy level distribution of the first or second substance. As a result, the HOMO energy level distribution or LUMO energy level distribution of the photoelectric conversion layer 30 containing the first, second, and third substances (without the third substance) differs from the HOMO energy level distribution or LUMO energy level distribution of the thin film made up of the first and second substances.

[0061] The dipole moment of the third substance is, for example, about 5.5 Debye or more, and within the above range, about 6 Debye or more, about 8 Debye or more, about 10 Debye or more, or about 12 Debye or more, and within the above range, about 5.5 to 15 Debye, about 6 to 15 Debye, about 8 to 15 Debye, about 10 to 15 Debye, or about 12 to 15 Debye, but is not limited to these.

[0062] The photoelectric conversion layer 30 includes a third substance having a high dipole moment as a dopant, thereby adjusting the first or second substance to have a distribution of HOMO energy levels or LUMO energy levels in a desired region, or to avoid having a distribution of HOMO energy levels or LUMO energy levels in an undesired region.

[0063] For example, if substance 1 is a p-type substance and substance 2 is an n-type substance, then substance 3 is a p-type substance that deforms the distribution of HOMO energy levels of substance 1. For example, the distribution of HOMO energy levels of substance 1, deformed by substance 3, shifts to deeper HOMO energy levels compared to the original distribution of HOMO energy levels of substance 1.

[0064] Thus, by shifting the distribution of HOMO energy levels in a p-type semiconductor, it is possible to increase the desired region within the HOMO energy level distribution, or decrease or eliminate the undesirable region within the HOMO energy level distribution. For example, it is possible to decrease or eliminate the shallow HOMO energy level region in the HOMO energy level distribution region of a p-type material where there are relatively many trap sites for charges (e.g., holes). For instance, it is possible to decrease or eliminate the HOMO energy level region shallower than approximately 5.2 eV in the HOMO energy level distribution of a p-type semiconductor.

[0065] For example, the distribution of the HOMO energy levels of the first substance, when deformed by the third substance, shifts towards deeper HOMO energy levels. In this case, the HOMO energy level of the third substance is either deeper or shallower than that of the first substance. For example, the HOMO energy level of the third substance is either deeper than that of the first substance or shallower within a range of approximately 0.3 eV or less. For instance, the HOMO energy level of the third substance falls within a range of approximately -0.3 eV to 1.2 eV (excluding 0 eV) compared to the HOMO energy level of the first substance. For example, the original HOMO energy level of the first substance is approximately 5.0 eV to 5.8 eV, while the HOMO energy level of the third substance is approximately 4.7 eV to 6.2 eV. For example, the HOMO energy level of the third substance is deeper than that of the first substance. For instance, the original HOMO energy level of the first substance is approximately 5.0 eV to 5.8 eV, while the HOMO energy level of the third substance is approximately 5.1 eV to 6.2 eV. The HOMO energy level of the first substance, after being altered by the third substance, is deeper than that of the first substance. For example, the HOMO energy level of the first substance deformed by the third substance is 0.001 eV deeper than the HOMO energy level of the first substance, and within the above range, it is approximately 0.001 eV to 1.2 eV, approximately 0.002 eV to 0.8 eV, approximately 0.003 eV to 0.4 eV, approximately 0.004 eV to 0.1 eV, approximately 0.005 eV to 0.08 eV, approximately 0.005 eV to 0.04 eV, approximately 0.005 eV to 0.03 eV, approximately 0.005 eV to 0.0 eV, or approximately 0.005 eV to 0.018 eV deeper.

[0066] For example, the HOMO energy level of the second substance, which is an n-type substance, is deeper than approximately 6.2 eV, and the HOMO energy level of the third substance lies between the HOMO energy levels of the first and second substances. For example, the difference between the HOMO energy level of the third substance and the HOMO energy level of the second substance is smaller than the difference between the HOMO energy levels of the first and second substances. For example, the intrinsic HOMO energy level of the first substance is approximately 5.0 eV to 5.8 eV, the HOMO energy level of the second substance is approximately 6.3 eV to 7.2 eV, and the HOMO energy level of the third substance is approximately 5.1 eV to 6.2 eV.

[0067] As a result, the HOMO energy level of the photoelectric conversion layer 30 containing the first, second, and third substances (without the third substance) is deeper than the HOMO energy level of the thin film made of the first and second substances. For example, the HOMO energy level of the photoelectric conversion layer 30 (without the third substance) is about 0.001 eV or more deeper than the HOMO energy level of the thin film made of the first and second substances, for example, about 0.001 eV to 1.2 eV, about 0.002 eV to 0.8 eV, about 0.003 eV to 0.4 eV, about 0.004 eV to 0.1 eV, about 0.005 eV to 0.08 eV, about 0.005 eV to 0.04 eV, about 0.005 eV to 0.03 eV, about 0.005 eV to 0.02 eV, and about 0.005 eV to 0.018 eV deeper.

[0068] The third substance is an organic, inorganic, and / or organic-inorganic substance exhibiting the properties described above, such as an organic substance, such as a low-molecular-weight compound, and such as a vapor-depositable organic compound. As an example, the photoelectric conversion layer 30 is a co-deposited thin film of the first substance, the second substance, and the third substance.

[0069] The third substance is, for example, a light-absorbing substance, which selectively absorbs light from one of the following wavelength regions: blue, green, red, and infrared.

[0070] As an example, the absorption spectra of substance 1 and substance 3 have a maximum absorption wavelength (λ) that is common to one of the following regions: the blue wavelength region, the green wavelength region, the red wavelength region, and the infrared wavelength region. max ) has. As an example, the absorption spectra of the first and third substances are, for each, in the blue wavelength region of approximately 380 nm to less than 500 nm, with the maximum absorption wavelength (λ). max ) has. For example, the absorption spectra of the first and third substances are, respectively, in the green wavelength region of approximately 500 nm to 600 nm, with the maximum absorption wavelength (λ). max ) has. As an example, the absorption spectra of the first and third substances are, for each, in the red wavelength region between approximately 600 nm and 700 nm, with the maximum absorption wavelength (λ). max ) has. For example, the absorption spectra of the first and third substances are such that the maximum absorption wavelength (λ) is in the infrared wavelength region from approximately 700 nm to 3,000 nm. max ) has.

[0071] The third substance is, for example, represented by chemical formula 1 below, but is not limited to this.

[0072] [Chemical formula 1] EDM3-HA3-EAM3

[0073] In the above chemical formula 1, HA3 is a π-conjugated moiety, which is a substituted or unsubstituted heterocyclic group having 2 to 30 carbon atoms. EDM3 is an electronic child and a moiety, EAM3 is an electron-accepting moiety.

[0074] For example, HA3 is the same as or different from HA1 described above, EDM3 is the same as or different from EDM1 described above, and EAM3 is the same as or different from EAM1 described above. However, at least one of HA3, EDM3, and EAM3 is different from HA1, EDM1, or EAM1.

[0075] For example, the third substance represented by chemical formula 1 may be represented by chemical formula 1-1 below, but is not limited to this.

[0076] [ka]

[0077] In the above chemical formula 1-1, X 2 is O, S, Se, Te, SO, SO2, SiR a R b , or GeR c R d And, Ar 2 This is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 30 carbon atoms, or two or more fused rings selected from these. Ar 1b and Ar 2b Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C3-C30 heteroaryl group. Ar 1b and Ar 2b These elements either exist independently or combine with each other to form a fused ring. R 4 ~R 6 and R a ~R d Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a halogen, or a cyano group.

[0078] As an example, Ar in chemical formula 1-1 1b and Ar 2bEach of these groups is independently selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenantrenyl group, a substituted or unsubstituted pyridinyl group, a substituted or unsubstituted pyridadinyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted isoquinolinyl group, a substituted or unsubstituted naphthylidinyl group, a substituted or unsubstituted cinolinyl group, a substituted or unsubstituted quinazolinyl group, a substituted or unsubstituted phthalazinyl group, a substituted or unsubstituted benzotriazinyl group, a substituted or unsubstituted pyridopyrazine group, a substituted or unsubstituted pyridopyrimidinyl group, or a substituted or unsubstituted pyridopyridazinyl group.

[0079] As an example, Ar in chemical formula 1-1 1b and Ar 2b They condense with each other to form a ring, Ar 1b and Ar 2b Examples include single bonds, -O-, -S-, -Se-, -Te-, -N=, -NR e -,-(CR f R g ) n2 -(n2 is 1 or 2), -SiR h R i -, -GeR j R k -,-(C(R l )=C(R m ))-, or SnR n R o They are connected to form a ring. Here, R e ~R o Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a halogen, or a cyano group, R f and R g , R h and R i , R j and R k , Rl and R m , and R n and R o These elements either exist independently or are connected to each other to form a ring.

[0080] For example, the third substance represented by chemical formula 1-1 may be represented by chemical formulas 1-2 to 1-7 below, but is not limited to these.

[0081] [ka]

[0082] In the above chemical formulas 1-2 to 1-7, X 2 and R 4 ~R 6 As stated above, Ar 4 This is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 30 carbon atoms, or two or more fused rings selected from these. Ar 5 These are substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms. Z represents single bonds, -O-, -S-, -Se-, -Te-, -N=, -NR e -,-(CR f R g ) n2 -(n2 is 1 or 2), -SiR h R i -, -GeR j R k -,-(C(R l )=C(R m ))-, or SnR n R o And here R e ~R oEach of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C12 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a halogen, or a cyano group, R f and R g , R h and R i , R j and R k , R l and R m and R n and R o They either exist independently or are connected to each other to form a ring. Y 3 is O, S, Se, Te, or C(R p )(CN)(R here p (These are hydrogen, a cyano group (-CN), or an alkyl group having 1 to 10 carbon atoms.) R 6f ~R 6j , R 7f ~R 7j , R 18 and R 19 Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a halogen, or a cyano group. R 6f ~R 6j These elements either exist independently or two adjacent elements are linked together to form a fused ring. R 7f ~R 7j These elements either exist independently or two adjacent elements are linked together to form a fused ring.

[0083] For example, Ar in chemical formulas 1-2, 1-4, or 1-6 4 is benzene, naphthalene, anthracene, thiophene, selenofen, telolofen, pyridine, pyrimidine, or two or more condensed rings selected from these.

[0084] The photoelectric conversion layer 30 is an intrinsic layer (layer I) in which the first, second, and third materials described above are mixed in a bulk heterojunction form.

[0085] The first substance and the second substance are mixed in a volume ratio of approximately 1:9 to 9:1, and within the above range, for example, in a volume ratio of approximately 2:8 to 8:2, and within the above range, for example, in a volume ratio of approximately 3:7 to 7:3, for example, approximately 4:6 to 6:4, or approximately 5:5.

[0086] The third substance is included in a quantity that does not affect the molecular stability of the first and second substances or other properties required of the photoelectric conversion layer 30, in addition to modifying the physical properties of the first and / or second substances as described above, for example, in a smaller quantity than the first or second substance. For example, the third substance is included in an amount of about 30% by volume or less relative to the total volume of the first and third substances, and within the above range, it is included in an amount of about 1-30% by volume, about 1-25% by volume, about 1-20% by volume, about 1-15% by volume, or about 1-10% by volume.

[0087] As an example, the photoelectric conversion layer 30 is a three-component system (ternary system) consisting of the first, second, and third substances described above.

[0088] The photoelectric conversion element 100 further includes an anti-reflective layer (not shown) disposed on one surface of the first electrode 10 or the second electrode 20. The anti-reflective layer can be placed on the side to which light is incident to further improve light absorption by reducing the reflectivity of the incident light. For example, when light is incident on the first electrode 10 side, the anti-reflective layer is disposed on one surface of the first electrode 10, and when light is incident on the second electrode 20 side, the anti-reflective layer is disposed on one surface of the second electrode 20.

[0089] The anti-reflective layer includes, for example, a substance having a refractive index of about 1.6 to 2.5, and includes, for example, at least one of metal oxides, metal sulfides, and organic substances having a refractive index within the above range. The anti-reflective layer includes, but is not limited to, metal oxides such as aluminum-containing oxides, molybdenum-containing oxides, tungsten-containing oxides, vanadium-containing oxides, rhenium-containing oxides, niobium-containing oxides, tantalum-containing oxides, titanium-containing oxides, nickel-containing oxides, copper-containing oxides, cobalt-containing oxides, manganese-containing oxides, chromium-containing oxides, tellurium-containing oxides, or combinations thereof; metal sulfides such as zinc sulfide; or organic substances such as amine derivatives.

[0090] When light is incident on the photoelectric conversion element 100 from either the first electrode 10 or the second electrode 20, and the photoelectric conversion layer 30 absorbs light in a predetermined wavelength range, excitons are generated inside. The excitons are separated into holes and electrons in the photoelectric conversion layer 30. The separated holes move to the anode of one of the first electrode 10 and the second electrode 20, and the separated electrons move to the cathode of the other of the first electrode 10 and the second electrode 20, causing an electric current to flow.

[0091] As described above, the photoelectric conversion layer 30 can achieve desired physical properties or eliminate undesirable physical properties by further including a third substance that modifies the physical properties of the first and / or second substance, in addition to the first and second substances that form the pn junction. This improves the optical and electrical characteristics of the photoelectric conversion element 100. As an example, as described above, by adjusting the energy level distribution of the first or second substance to reduce or eliminate regions of energy levels in the photoelectric conversion layer 30 where there are relatively many charge trap sites (for example, regions of shallow HOMO energy levels), residual charges remaining at trap sites in charges moving from the photoelectric conversion layer 30 to the first electrode 10 and / or the second electrode 20 can be reduced or prevented. In this way, image afterimages caused by residual charges accumulated in the photoelectric conversion layer 30 can be reduced or prevented, thereby improving the electrical performance of the photoelectric conversion element 100.

[0092] Figure 2 is a cross-sectional view showing another example of a photoelectric conversion element according to one embodiment.

[0093] Referring to Figure 2, the photoelectric conversion element 100 according to this embodiment includes a first electrode 10, a second electrode 20, and a photoelectric conversion layer 30, similar to the embodiment described above. However, unlike the embodiment described above, the photoelectric conversion element 100 according to this embodiment further includes auxiliary layers (40, 50) between the first electrode 10 and the photoelectric conversion layer 30, and between the second electrode 20 and the photoelectric conversion layer 30.

[0094] The auxiliary layers (40, 50) are, but are not limited to, a hole injecting layer (HIL) for facilitating hole injection, a hole transporting layer (HTL) for facilitating hole transport, an electron blocking layer (EBL) for preventing electron movement, an electron injecting layer (EIL) for facilitating electron injection, an electron transporting layer (ETL) for facilitating electron transport, and / or a hole blocking layer (HBL) for preventing hole movement.

[0095] Each auxiliary layer (40, 50) independently contains organic matter, inorganic matter, and / or organic-inorganic matter.

[0096] As an example, one of the auxiliary layers (40, 50) includes an inorganic auxiliary layer. The inorganic auxiliary layer includes, for example, lanthanum group elements, calcium (Ca), potassium (K), aluminum (Al), or alloys thereof, and the lanthanum group elements include, for example, ytterbium (Yb). The thickness of the inorganic auxiliary layer is approximately 5 nm or less.

[0097] For example, one of the auxiliary layers (40, 50) includes an organic auxiliary layer. The organic auxiliary layer includes, but is not limited to, compounds represented by the following chemical formulas 2A or 2B.

[0098] [ka]

[0099] In the above chemical formula 2A or 2B, M 1 and M 2 These are O, S, Se, Te, and CR, each independently. q R r , SiR s R t , or NR u And, Ar 1c Ar 2c Ar 3c , and Ar 4c Each of these is independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms. G 2 and G 3 These are, independently, single bonds, -(CR v R w ) n3 -, -O-, -S-, -Se-, -Te, -N=, -NR x -, or -SiR y R z -and here n3 is either 1 or 2, R 30 ~R 37 and R q ~R z Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heterocyclic group, a halogen, or a cyano group.

[0100] For example, the organic auxiliary layer is a compound represented by the following chemical formula 2A-1 or 2B-1, but is not limited to these.

[0101] [ka]

[0102] In the above chemical formula 2A-1 or 2B-1, M 1 M 2 , G 2 , G 3 , R 30 ~R 37 As stated above, R 38 ~R 45Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a halogen, or a cyano group.

[0103] For example, the organic auxiliary layer is a compound represented by the following chemical formulas 2A-1a or 2B-1a, but is not limited to these.

[0104] [ka]

[0105] In the above chemical formulas 2A-1a and 2B-1a, R 38 ~R 45 This is as explained in the above chemical formulas 2A-1 and 2B-1, R n ~R o In the above chemical formulas 2A and 2B, R q and R r As explained above.

[0106] For example, one of the auxiliary layers (40, 50) is an inorganic auxiliary layer, and the other of the auxiliary layers (40, 50) is an organic auxiliary layer. For example, one of the auxiliary layers (40, 50) can be omitted.

[0107] The photoelectric conversion element 100 described above is applied to, for example, a sensor, which is, for example, an image sensor. The image sensor to which the photoelectric conversion element 100 described above is applied is suitable for high-speed imaging by reducing image afterimages caused by residual charge.

[0108] Below, an example of an image sensor using the above-mentioned elements will be described with reference to the drawings. Here, an organic CMOS image sensor will be described as an example of an image sensor.

[0109] Figure 3 is a cross-sectional view showing an example of an image sensor according to one embodiment.

[0110] Referring to Figure 3, the image sensor 300 according to this embodiment includes a semiconductor substrate 110, an insulating layer 80, a photoelectric conversion element 100, and a color filter layer 70.

[0111] The semiconductor substrate 110 is a silicon substrate on which transmission transistors (not shown) and charge storage units 155 are integrated. The transmission transistors and / or charge storage units 155 are integrated for each pixel. The charge storage units 155 are electrically connected to the photoelectric conversion element 100.

[0112] Furthermore, metal wiring (not shown) and pads (not shown) are formed on the semiconductor substrate 110. The metal wiring and pads are made of metals with low resistivity to reduce signal delay, such as aluminum (Al), copper (Cu), silver (Ag), and alloys thereof, but are not limited to these.

[0113] An insulating layer 80 is formed on the metal wiring and pads. The insulating layer 80 is made of an inorganic insulating material such as silicon oxide and / or silicon nitride, or a low dielectric constant (low K) material such as SiC, SiCOH, SiCO, and SiOF. The insulating layer 80 has trenches 85 that expose charge storage 155. The trenches 85 are filled with a filler material.

[0114] A photoelectric conversion element 100 is formed on the insulating layer 80. The photoelectric conversion element 100 has the structure shown in Figure 1 or Figure 2, and a detailed explanation is as described above. One of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is a photoreceiving electrode, and the other of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is connected to a charge storage unit 155.

[0115] A color filter layer 70 is formed on the photoelectric conversion element 100. The color filter layer 70 includes a blue filter 70a formed on the blue pixels, a red filter 70b formed on the red pixels, and a green filter 70c formed on the green pixels. However, it is not limited to these, and may include a cyan filter, a magenta filter, and / or a yellow filter instead or in addition.

[0116] An insulating film 180 is formed between the photoelectric conversion element 100 and the color filter layer 70. The insulating film 180 can be omitted.

[0117] A focusing lens (not shown) is further formed on the color filter layer 70. The focusing lens controls the direction of incident light to concentrate it to a single point. The focusing lens may be, for example, cylindrical or hemispherical, but is not limited to these shapes.

[0118] Figure 4 is a plan view showing an example of an image sensor according to one embodiment, and Figure 5 is a cross-sectional view showing an example of the image sensor in Figure 4.

[0119] Referring to Figures 4 and 5, the image sensor 400 according to this embodiment includes a semiconductor substrate 110 on which light sensing elements (150a, 150b), a transmission transistor (not shown), and a charge storage 155 are integrated, a lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a photoelectric conversion element 100.

[0120] The semiconductor substrate 110 is a silicon substrate on which light sensing elements (150a, 150b), a transmission transistor (not shown), and a charge storage unit 155 are integrated. The light sensing elements (150a, 150b) are photodiodes.

[0121] The light-sensing elements (150a, 150b), transmission transistors, and / or charge storage units 155 are integrated for each pixel. For example, as can be seen in the drawing, the light-sensing elements (150a, 150b) are included in the blue and red pixels, respectively, and the charge storage unit 155 is included in the green pixel.

[0122] The light sensing elements (150a, 150b) sense light, and the sensed information is transmitted by a transmission transistor. The charge storage 155 is electrically connected to the photoelectric conversion element 100, and the information from the charge storage 155 is transmitted by a transmission transistor.

[0123] Furthermore, metal wiring (not shown) and pads (not shown) are formed on the semiconductor substrate 110. The metal wiring and pads are made of metals with low resistivity to reduce signal delay, such as aluminum (Al), copper (Cu), silver (Ag), and alloys thereof, but are not limited to these. However, the structure is not limited to the above, and the metal wiring and pads may also be located beneath the photosensing elements (150a, 150b).

[0124] A lower insulating layer 60 is formed on the metal wiring and pads. The lower insulating layer 60 is made of an inorganic insulating material such as silicon oxide and / or silicon nitride, or a low dielectric constant (low K) material such as SiC, SiCOH, SiCO, and SiOF. The lower insulating layer 60 has trenches 85 that expose the charge storage 155. The trenches 85 are filled with a filler material.

[0125] A color filter layer 70 is formed on the lower insulating film 60. The color filter layer 70 includes a blue filter 70a formed on the blue pixels and a red filter 70b formed on the red pixels. However, it is not limited to this, and a cyan filter, a magenta filter, and / or a yellow filter may be included instead or additionally. In this embodiment, an example without a green filter is described, but a green filter may be included in some cases.

[0126] An upper insulating layer 80 is formed on top of the color filter layer 70. The upper insulating layer 80 is flattened to remove the step caused by the color filter layer 70. The upper insulating layer 80 and the lower insulating layer 60 have contact holes (not shown) that expose the pads and trenches 85 that expose the charge storage 155 of the green pixels.

[0127] A photoelectric conversion element 100 is formed on the upper insulating layer 80. The photoelectric conversion element 100 has the structure shown in Figure 1 or Figure 2, and a detailed explanation is as described above. One of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is a photoreceiving electrode, and the other of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is connected to a charge storage unit 155.

[0128] A focusing lens (not shown) is further formed on the photoelectric conversion element 100. The focusing lens controls the direction of incident light to concentrate it to a single point. The focusing lens is, for example, cylindrical or hemispherical, but is not limited to these shapes.

[0129] Figure 6 is a cross-sectional view showing another example of the image sensor shown in Figure 4.

[0130] Referring to Figure 6, the image sensor 500 according to this embodiment, similar to the embodiment described above, includes a semiconductor substrate 110 on which light sensing elements (150a, 150b), a transmission transistor (not shown), and a charge storage 155 are integrated, an upper insulating layer 80, and a photoelectric conversion element 100.

[0131] However, unlike the embodiments described above, the image sensor 500 according to this embodiment has the photosensing elements (150a, 150b) stacked vertically, and the lower insulating layer 60 and color filter layer 70 are omitted. The photosensing elements (150a, 150b) are electrically connected to a charge storage (not shown) and transmitted by a transmission transistor. The photosensing elements (150a, 150b) selectively absorb light in each wavelength range depending on the stacking depth.

[0132] The photoelectric conversion element 100 has the structure shown in Figure 1 or Figure 2, and a detailed explanation is as described above. One of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is a photoreceiving electrode, and the other of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is connected to the charge storage 155.

[0133] Figure 7 is a plan view showing another example of an image sensor according to one embodiment, and Figure 8 is a cross-sectional view showing an example of the image sensor in Figure 7.

[0134] The image sensor 600 according to this embodiment has a structure in which a green element that selectively absorbs light in the green wavelength region, a blue element that selectively absorbs light in the blue wavelength region, and a red element that selectively absorbs light in the red wavelength region are stacked.

[0135] The image sensor 600 according to this embodiment includes a semiconductor substrate 110, a lower insulating layer 60, an intermediate insulating layer 65, an upper insulating layer 80, a first photoelectric conversion element 100a, a second photoelectric conversion element 100b, and a third photoelectric conversion element 100c.

[0136] The semiconductor substrate 110 is a silicon substrate on which transmission transistors (not shown) and charge storage units (155a, 155b, 155c) are integrated.

[0137] Metal wiring (not shown) and pads (not shown) are formed on the semiconductor substrate 110, and a lower insulating layer 60 is formed on the metal wiring and pads.

[0138] A first photoelectric conversion element 100a, a second photoelectric conversion element 100b, and a third photoelectric conversion element 100c are sequentially formed on the lower insulating layer 60.

[0139] The first, second, and third photoelectric conversion elements (100a, 100b, and 100c) each have the structure shown in Figure 1 or Figure 2 independently, and a detailed explanation is provided above. One of the first electrode 10 and the second electrode 20 of the first, second, and third photoelectric conversion elements (100a, 100b, and 100c) is a photoreceiving electrode, and the other of the first electrode 10 and the second electrode 20 of the first, second, and third photoelectric conversion elements (100a, 100b, and 100c) is connected to a charge storage unit (155a, 155b, and 155c).

[0140] The first photoelectric conversion element 100a selectively absorbs light in one of the wavelength ranges of red, blue, and green and converts it into electricity. For example, the first photoelectric conversion element 100a is a red photoelectric conversion element. An intermediate insulating layer 65 is formed on the first photoelectric conversion element 100a.

[0141] A second photoelectric conversion element 100b is formed on the intermediate insulating layer 65.

[0142] The second photoelectric conversion element 100b selectively absorbs light in one of the wavelength ranges of red, blue, and green and converts it into electricity. For example, the second photoelectric conversion element 100b is a blue photoelectric conversion element.

[0143] An upper insulating layer 80 is formed on the second photoelectric conversion element 100b. The lower insulating layer 60, the intermediate insulating layer 65, and the upper insulating layer 80 have a plurality of trenches (85a, 85b, 85c) that expose charge storage areas (155a, 155b, 155c).

[0144] A third photoelectric conversion element 100c is formed on the upper insulating layer 80. The third photoelectric conversion element 100c selectively absorbs light in one of the wavelength regions of red, blue, and green and converts it into electricity. For example, the third photoelectric conversion element 100c is a green photoelectric conversion element.

[0145] A focusing lens (not shown) is further formed on the third photoelectric conversion element 100c. The focusing lens controls the direction of the incident light to concentrate it to a single point. The focusing lens may be, for example, cylindrical or hemispherical, but is not limited to these shapes.

[0146] The drawing shows a structure in which the first photoelectric conversion element 100a, the second photoelectric conversion element 100b, and the third photoelectric conversion element 100c are stacked in sequence, but the structure is not limited to this, and the stacking order can be changed in various ways.

[0147] As described above, by having a structure in which the first photoelectric conversion element 100a, the second photoelectric conversion element 100b, and the third photoelectric conversion element 100c, which each absorb light in different wavelength regions, are stacked, the size of the image sensor can be further reduced, thereby achieving miniaturization of the image sensor.

[0148] Figure 9 is a plan view showing another example of an image sensor according to one embodiment, and Figure 10 is a cross-sectional view showing an example of the image sensor in Figure 9.

[0149] Referring to Figures 9 and 10, the image sensor 1100 includes a photoelectric conversion element 90 disposed on a semiconductor substrate 110, the photoelectric conversion element 90 includes a plurality of photoelectric conversion elements (90-1, 90-2, 90-3). Each of the plurality of photoelectric conversion elements (90-1, 90-2, 90-3) converts light in different wavelength regions (e.g., blue light, green light, or red light) into an electrical signal. Referring to Figure 10, the plurality of photoelectric conversion elements (90-1, 90-2, 90-3) are arranged horizontally on the semiconductor substrate 110 and partially or completely overlap each other in a direction extending parallel to the surface 110a of the semiconductor substrate 110. Each photoelectric conversion element (90-1, 90-2, 90-3) is connected to a charge storage 155 integrated within the semiconductor substrate 110 through a trench 85.

[0150] Each photoelectric conversion element (90-1, 90-2, 90-3) is one of the photoelectric conversion elements (100, 200) described above. For example, two or more photoelectric conversion elements (90-1, 90-2, 90-3) include different portions of a common continuous layer that extends continuously between the photoelectric conversion elements (90-1, 90-2, 90-3). For example, multiple photoelectric conversion elements (90-1, 90-2, 90-3) share a common first electrode 10 and / or a common second electrode 20. For example, two or more photoelectric conversion elements (90-1, 90-2, 90-3) have different photoelectric conversion layers 30 that absorb light in different wavelength regions of incident light. The other structure of the image sensor 1100 is similar to one or more of the image sensors described in Figures 3 to 8.

[0151] Figure 11 is a cross-sectional view showing an example of an image sensor according to one embodiment.

[0152] Referring to Figure 11, the image sensor 1200 includes a semiconductor substrate 110 and photoelectric conversion elements (90-1, 91) stacked on the semiconductor substrate 110. Photoelectric conversion element 91 includes a plurality of photoelectric conversion elements (90-2, 90-3), which are arranged to overlap in a direction parallel to the surface 110a of the semiconductor substrate 110. Each of the plurality of photoelectric conversion elements (90-1, 90-2, 90-3) photoelectrically converts light in different wavelength regions (e.g., blue light, green light, or red light) into an electrical signal.

[0153] For example, the photoelectric conversion element 91 includes a plurality of horizontally arranged photoelectric conversion elements that absorb light in different wavelength regions. For example, the photoelectric conversion element 91 photoelectrically converts light in one wavelength region selected from blue light, green light, and red light. For example, the photoelectric conversion element 91 overlaps the photoelectric conversion element 90-1 entirely or partially. The other structure of the image sensor 1200 is similar to one or more of the image sensors described in Figures 3 to 8.

[0154] Figure 12 is a cross-sectional view showing another example of an image sensor according to one embodiment.

[0155] Referring to Figure 12, the image sensor 1300 includes a semiconductor substrate 110 on which light sensing elements (150a, 150b), a transmission transistor (not shown), and a charge storage 155 are integrated; an upper insulating layer 80 and a color filter layer 70 located above the semiconductor substrate 110; and a lower insulating layer 60 and a photoelectric conversion element 90 located below the semiconductor substrate 110. The photoelectric conversion element 90 is the aforementioned photoelectric conversion element (100, 200). In Figure 12, the photoelectric conversion element 90 is located below the semiconductor substrate 110, so that the photoelectric conversion element 90 and the color filter layer 70 are separated from the light sensing elements (150a, 150b). The other structures of the image sensor 1300 are the same as one or more of the image sensors described in Figures 3 to 8.

[0156] The photoelectric conversion elements and sensors described above are applied to a variety of electronic devices, such as mobile phones, cameras, biorecognition devices, and / or automotive electrical components, but are not limited to these.

[0157] Figure 13 is a schematic diagram of an electronic device according to one embodiment.

[0158] Referring to Figure 13, the electronic device 1700 includes a processor 1720, a memory 1730, and an image sensor 1740, which are electrically connected to each other via a bus 1710. The image sensor 1740 is one of the embodiments described above. The memory 1730, a non-temporary computer-readable storage medium, stores instruction programs. The memory 1730 is a non-volatile memory such as flash memory, phase-change random access memory (PRAM), magneto-resistive RAM (MRAM), resistive RAM (ReRAM), or ferro-electric RAM (FeRAM); or a volatile memory such as SRAM, DRAM, or SDRAM. The processor 1720 executes the stored instruction programs to perform one or more functions. As an example, the processor 1720 processes electrical signals generated by the image sensor 1740. Based on such processing, the processor 1720 generates an output (e.g., an image displayed on a display interface).

[0159] The embodiments described above will be explained in more detail below through the examples. However, the following examples are for illustrative purposes only and do not limit the scope of the present invention.

[0160] <<Simulation Evaluation>>

[0161] (1) Examples and Comparative Examples

[0162] For simulation evaluation, assume that as the first substance, the following compound B; as the second substance, fullerene (C 60 ); and as the third substance, one of the following compounds C-1 to C-5. As shown in Table 1 below, for a thin film containing the first substance, the second substance, and the third substance, based on the molecular structures of the first substance, the second substance, and the third substance, the atomistic morphology was predicted by molecular dynamics, quantum calculations were performed on all the molecules included in the morphology, and the distribution of energy levels was evaluated. At this time, assume that the first substance and the second substance are contained in a 1:1 (volume ratio), and the third substance is contained at 5% by volume with respect to the total volume of the first substance and the third substance.

[0163] The quantum calculation is performed considering the conformation and the surrounding environment of each molecule in the morphology. Thereby, the distribution of energy levels considering the morphological change of the first substance or the environmental change of the molecule according to the influence of the third substance is evaluated.

[0164] [Table 1]

[0165] [Chemical formula]

[0166] <H (2) Evaluation of physical properties of substances

[0167] The physical properties of the first substance, the second substance, and the third substance are as shown in Table 2.

[0168] The HOMO energy level distribution simulation is performed using Quantumpatch software (Nanomatch GmbH), and the molecular dipole moment simulation is performed using Jaguar software (Schrodinger, LLC, Materials science suite). However, Quantumpatch software is B3LYP / def2-SVP and Jaguar software is LACV3P. ** Perform Density Functional Theory (DFT) calculation using the basis set.

[0169] [Table 2]

[0170] (3) Simulation Results I

[0171] The change in residual charge in response to the change in the distribution of the HOMO energy levels of the first substance was evaluated by simulation.

[0172] Figure 14 is a graph showing the change in the distribution of HOMO energy levels of the first substance, and Figures 15 and 16 are graphs showing the change in residual charge in response to the change in the distribution of HOMO energy levels of the first substance.

[0173] Referring to Figures 14 to 16, it can be predicted that the residual charge properties of the first substance will improve as the distribution of the HOMO energy levels shifts to deeper levels.

[0174] (4) Simulation Results II

[0175] The changes in the energy levels of the first substance and the resulting changes in residual charge were evaluated through simulation.

[0176] The results are shown in Table 3.

[0177]

Table 3

[0178] Referring to Table 3 above, it is expected that the characteristics of the residual charge are improved as the HOMO energy level of the first substance becomes deeper, and it can be predicted that the characteristics of the residual charge are further improved as the change in the HOMO energy level of the first substance becomes larger.

[0179] ≪Device Evaluation≫

[0180] (1) Fabrication of Device

[0181] The following photoelectric conversion device is fabricated and the simulation evaluation is experimentally verified.

[0182] <Device Example 1>

[0183] ITO was laminated on a glass substrate by sputtering to form an anode with a thickness of 150 nm. Next, Compound A below was vapor-deposited on the anode to form a charge blocking layer with a thickness of 5 nm. Next, Chemical Formula B (the first substance) (λ max : 545 nm), fullerene (C 60 ), and Compound C-1 (the third substance) (λ max : 551 nm) were co-vapor-deposited to form a photoelectric conversion layer with a thickness of 100 nm. At this time, the first substance and the second substance were co-vapor-deposited at a volume (bulk) ratio of 1:1, and the third substance was co-vapor-deposited so as to be 5% by volume with respect to the total volume of the first substance and the third substance. The deformed HOMO energy level of the first substance in the photoelectric conversion layer is 5.495 eV, and the LUMO energy level of fullerene is 3.563 eV. Next, Yb was thermally vapor-deposited on the photoelectric conversion layer to form an electron buffer layer (WF: 2.6 eV) with a thickness of 1.5 nm. Next, ITO was sputtered on the electron buffer layer to form a cathode with a thickness of 7 nm. Next, aluminum oxide (Al2O3) was vapor-deposited on the cathode to form an antireflection layer with a thickness of 50 nm, and it was sealed with a glass plate to fabricate a photoelectric conversion device.

[0184] [ka]

[0185] <Example 2 of the element>

[0186] As the third substance, compound C-2 (λ) is used instead of compound C-1. max A photoelectric conversion element was fabricated in the same manner as in Element Example 1, except that a photoelectric conversion layer was formed using a 538 nm (538 nm) element. The deformed HOMO energy level of the first material in the photoelectric conversion layer is 5.502 eV.

[0187] <Example 3 of this element>

[0188] As the third substance, compound C-3 (λ) is used instead of compound C-1. max A photoelectric conversion element was fabricated in the same manner as in Element Example 1, except that a photoelectric conversion layer was formed using 540 nm. The deformed HOMO energy level of the first material in the photoelectric conversion layer is 5.508 eV.

[0189] <Comparative Example 1>

[0190] A photoelectric conversion element was manufactured in the same manner as in Element Example 1, except that the third substance was not included and the photoelectric conversion layer was formed by co-depositing the first and second substances. The deformed HOMO energy level of the first substance in the photoelectric conversion layer is 5.490 eV.

[0191] <Comparative Example 2>

[0192] As the third substance, compound C-4 (λ) is used instead of compound C-1. max A photoelectric conversion element was fabricated in the same manner as in Element Example 1, except that a photoelectric conversion layer was formed using (534 nm). The deformed HOMO energy level of the first material in the photoelectric conversion layer is 5.479 eV.

[0193] <Comparative Example 3>

[0194] A photoelectric conversion element was manufactured in the same manner as in Element Example 1, except that compound C-5 was used instead of compound C-1 as the third material to form the photoelectric conversion layer. The deformed HOMO energy level of the first material in the photoelectric conversion layer is 5.482 eV.

[0195] (3) Evaluation

[0196] The residual charge characteristics of photoelectric conversion elements were evaluated using both example and comparative example devices.

[0197] Residual charge characteristics refer to the amount of charge that remains after photoelectric conversion in one frame and is not used for signal processing, and whose charge from the previous frame is read in the next frame. The elements in the examples and comparative examples were irradiated with light in the green wavelength region where photoelectric conversion occurs for 33 milliseconds, and after the light was turned off, the results were measured using a Keithley 2400 device. -6 The current is evaluated based on measurements taken in seconds. The amount of residual electrons is h+ / s / μm at 5,000 lux. 2 Evaluate in units.

[0198] The results are shown in Table 4.

[0199] [Table 4]

[0200] Referring to Table 4 above, it was confirmed that the device according to the device example showed improved residual electron characteristics compared to the device according to the device comparison example. Furthermore, it was confirmed that the device example yielded results substantially similar to the simulation results described above.

[0201] Although embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the embodiments described above, and can be modified and implemented in various ways without departing from the technical spirit of the present invention. [Explanation of Symbols]

[0202] 10 1st electrode 20 2nd electrode 30 Photoelectric conversion layer 40, 50 auxiliary layer 60 Lower insulating layer 65 Intermediate insulating layer 70 color filter layers 70a, 70b, 70c Blue, Red, Green Filters 80 (Upper) Insulating Layer 85, 85a, 85b, 85c Trench 90, 90-1, 90-2, 90-3, 91, 100 Photoelectric conversion elements 100a, 100b, 100c First to third photoelectric conversion elements 110 Semiconductor substrates 110a surface 150a, 150b, 150c Light-sensing elements 155, 155a, 155b, 155c Charge storage 180 insulating film 300, 400, 500, 600, 1100, 1200, 1300 Image Sensors 1700 Electronic equipment 1710 Bus 1720 Processor 1730 memory 1740 Image Sensor

Claims

1. The device comprises a first electrode, a second electrode, and a photoelectric conversion layer located between the first electrode and the second electrode. The photoelectric conversion layer comprises a mixture of different first, second, and third substances. The first and third substances are absorbent materials having the maximum absorption wavelength in one of the first wavelength regions: the blue wavelength region, the green wavelength region, the red wavelength region, and the infrared wavelength region. The dipole moment of the third substance is 5.6959 Debye or greater. The third substance is included in an amount of 30% or less by volume relative to the total volume of the first and third substances. The first substance is a photoelectric conversion element characterized by being represented by the following compound B. 【B】

2. The first and third substances are p-type substances, The photoelectric conversion element according to claim 1, characterized in that the second substance is an n-type substance.

3. The photoelectric conversion element according to claim 1, characterized in that the HOMO energy level of the third substance is deeper than or shallower than the HOMO energy level of the first substance within the range of 0.3 eV or less.

4. The HOMO energy levels of the third substance are 4.7 eV to 6.2 eV. The photoelectric conversion element according to claim 1, characterized in that the HOMO energy level of the first substance is 5.0 eV to 5.8 eV.

5. The HOMO energy levels of the third substance are 5.1 eV to 6.0 eV. The photoelectric conversion element according to claim 4, characterized in that the HOMO energy level of the first substance is 5.0 eV to 5.8 eV.

6. The photoelectric conversion element according to claim 1, characterized in that the third substance is contained in an amount of 1 to 10 volume percent relative to the total volume of the first substance and the third substance.

7. The photoelectric conversion element according to claim 1, characterized in that the photoelectric conversion layer is a three-component system consisting of the first substance, the second substance, and the third substance.

8. The photoelectric conversion element according to claim 1, characterized in that the third substance is represented by the following chemical formula 1-1. 【Chemistry 1-1】 In the above chemical formula 1-1, X ２ O, S, Se, Te, SO, SO ２ , SiR ａ R ｂ , or GeR ｃ R ｄ And, Ar ２ This is a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 30 carbon atoms, or two or more fused rings selected from these. Ar １ｂ and Ar ２ｂ are each independently hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, Ar １ｂ and Ar ２ｂ These elements either exist independently or combine with each other to form a fused ring. R ４ ~R ６ and R ａ ~R ｄ Each of these is independently hydrogen, deuterium, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group, a halogen, or a cyano group.

9. The photoelectric conversion element according to claim 1, characterized in that the second substance includes an inorganic substance, thiophene or a thiophene derivative, fullerene or a fullerene derivative, or a combination thereof.

10. A sensor characterized by including a photoelectric conversion element according to any one of claims 1 to 9.

11. An electronic device characterized by including the sensor described in claim 10.

12. An electronic device characterized by including a photoelectric conversion element according to any one of claims 1 to 9.

Images