Photoelectric conversion element, sensor, and electronic device

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

[0002] The photoelectric conversion element is an element that receives light and converts it into an electrical signal, and includes photodiodes and phototransistors, and is used as a sensor or a photodetector.

[0003] Sensors are required to have higher and higher resolution, which is leading to smaller pixel sizes. In the case of silicon photodiodes, which are mainly used at present, the absorption area decreases as the pixel size decreases, resulting in a decrease in sensitivity. As a result, research is being conducted into organic materials that can replace silicon.

[0004] Organic materials have a large absorption coefficient and can selectively absorb light in a specific wavelength range depending on their molecular structure, so they can simultaneously replace photodiodes and color filters, which is advantageous for high integration.

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

[0006] [Patent Document 1] JP 2019-140677 A Summary of the Invention [Problem to be solved by the invention]

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

[0008] In order to achieve the above-mentioned object, a photoelectric conversion element according to one embodiment 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, the photoelectric conversion layer containing a mixture of a first substance, a second substance, and a third substance, each of which is a different substance, the first substance and the third substance being light-absorbing substances having a maximum absorption wavelength in a first wavelength region which is any one of a blue wavelength region, a green wavelength region, a red wavelength region, and an infrared wavelength region, the dipole moment of the third substance being 5.5 Debye or more, and the third substance being contained in an amount of 30 volume % or less with respect to the total volume of the first substance and the third substance.

[0009] The first material and the third material may be p-type materials, and the second material may be an n-type material. The HOMO energy level of the third material can be deeper than the HOMO energy level of the first material or within 0.3 eV or less. The third material may have a HOMO energy level of 4.7 eV to 6.2 eV, and the first material may have a HOMO energy level of 5.0 eV to 5.8 eV. The third material may have a HOMO energy level of 5.1 eV to 6.0 eV, and the first material may have a HOMO energy level of 5.0 eV to 5.8 eV. The third material may be included in an amount of 1 to 10% by volume based on the total volume of the first material and the third material. The photoelectric conversion layer may be a three-component system including the first material, the second material, and the third material.

[0010] The third material may be represented by the following formula 1-1. [ka] In the above Chemical Formula 1-1, X 2 are O, S, Se, Te, SO, and SO 2 , SiR a R b , or GeR c R d and Ar 2 represents 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 independently represents 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 fused ring, R 4 ~R 6 and R a ~R d 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.

[0011] The first substance may be represented by the following chemical formula A-1. [ka] In the above chemical formula A-1, X 1 are O, S, Se, Te, SO, and SO 2 , SiR a R b , or GeR c R d and Ar 1 represents 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 independently represents 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 1a and Ar 2a each independently exists or combines with each other to form a fused ring, R 1 ~R 3 and R a ~R d 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. The second material may include an inorganic material, a thiophene or a thiophene derivative, a fullerene or a fullerene derivative, or a combination thereof.

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

[0013] In order to achieve the above object, an electronic device according to one aspect of the present invention includes the photoelectric conversion element or the sensor. Effect of the Invention

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

[0015] [Figure 1] 1 is a cross-sectional view illustrating an example of a photoelectric conversion element according to an embodiment. [Diagram 2] FIG. 4 is a cross-sectional view showing another example of a photoelectric conversion element according to an embodiment. [Diagram 3] FIG. 1 is a cross-sectional view illustrating an example of an image sensor according to an embodiment. [Figure 4] FIG. 2 is a plan view illustrating an example of an image sensor according to an embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing an example of the image sensor of FIG. [Figure 6] 5 is a cross-sectional view showing another example of the image sensor of FIG. 4. [Figure 7] FIG. 2 is a plan view illustrating another example of an image sensor according to an embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing an example of the image sensor of FIG. [Figure 9] FIG. 2 is a plan view illustrating another example of an image sensor according to an embodiment. [Figure 10] 10 is a cross-sectional view showing an example of the image sensor of FIG. 9. [Figure 11] FIG. 1 is a cross-sectional view illustrating an example of an image sensor according to an embodiment. [Figure 12] FIG. 2 is a cross-sectional view illustrating another example of an image sensor according to an embodiment. [Figure 13] 1 is a schematic diagram of an electronic device according to an embodiment. [Figure 14] 1 is a graph showing a change in distribution of the HOMO energy levels of a first substance. [Figure 15] 1 is a graph showing the change in residual charge according to the change in the distribution of the HOMO energy levels of a first substance. [Figure 16] 1 is a graph showing the change in residual charge according to the change in the distribution of the HOMO energy levels of a first substance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, specific examples of embodiments of the present invention will be described in detail with reference to the drawings. However, the actual structure may be embodied in various different forms and is not limited to the embodiments described herein.

[0017] In the drawings, the thicknesses of the various layers and regions are exaggerated for clarity.

[0018] When a part such as a layer, film, region, or plate is said to be "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part between them. Conversely, when a part is said to be "directly on" another part, it means that there is no other part between them.

[0019] Unless otherwise defined below, "substituted" means that a hydrogen atom in a compound is replaced with a halogen atom, a hydroxy group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamoyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a silyl group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkyl group having 6 to 8 carbon atoms, or a substituted or unsubstituted alkyl group having 6 to 8 carbon atoms. It means that the group is substituted with a substituent selected from an aryl group having from 7 to 30 carbon atoms, an arylalkyl group having from 7 to 30 carbon atoms, an alkoxy group having from 1 to 30 carbon atoms, a heteroalkyl group having from 1 to 20 carbon atoms, a heteroaryl group having from 3 to 20 carbon atoms, a heteroarylalkyl group having from 3 to 20 carbon atoms, a cycloalkyl group having from 3 to 30 carbon atoms, a cycloalkenyl group having from 3 to 15 carbon atoms, a cycloalkynyl group having from 6 to 15 carbon atoms, a heterocycloalkyl group having from 3 to 30 carbon atoms, and combinations thereof.

[0020] Unless otherwise defined below, "hetero" means containing 1 to 4 heteroatoms selected from N, O, S, Se, Te, Si, and P.

[0021] Hereinafter, the term "combination" includes mixtures and laminated structures of two or more.

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

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

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

[0025] Hereinafter, a photoelectric conversion element according to an embodiment of the present invention will be described with reference to the drawings.

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

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

[0028] The substrate (not shown) is disposed on the first electrode 10 side or the second electrode 20 side. The substrate is made of an inorganic material such as glass; a silicon wafer; or an organic material such as polycarbonate, polymethylmethacrylate, polyethyleneterephthalate, polyethylenenaphthalate, polyamide, polyethersulfone, or a combination thereof. The substrate may be omitted.

[0029] Any one of the first electrode 10 and the second electrode 20 is an anode, and the other is a cathode. For example, the first electrode 10 is an anode, and the second electrode 20 is a cathode. For example, the first electrode 10 is a cathode, and the second electrode 20 is an 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 an oxide conductor, a carbon conductor, and a metal thin film, for example, the oxide conductor is one or more selected from 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 nano bodies, and the metal thin film is a very thin film including aluminum (Al), magnesium (Mg), silver (Ag), gold (Au), an alloy thereof, or a combination thereof.

[0031] Any one of the first electrode 10 and 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 includes a reflective conductor such as a metal, for example, aluminum (Al), silver (Ag), gold (Au), or an alloy thereof.

[0032] As an example, the first electrode 10 and the second electrode 20 are each a transparent electrode, and one of the first electrode 10 and the second electrode 20 is a light-receiving electrode.

[0033] As an example, the first electrode 10 is a transparent electrode, the second electrode 20 is a reflective electrode, and the first electrode 10 is a light-receiving electrode.

[0034] As an example, the first electrode 10 is a reflective electrode, the second electrode 20 is a transparent electrode, and the second electrode 20 is a light-receiving electrode.

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

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

[0037] For example, the photoelectric conversion layer 30 selectively absorbs any one of blue light, green light, red light, and infrared light and converts it into an electrical signal. Here, selectively absorbing any one of blue light, green light, red light, and infrared light means selectively absorbing any one of blue light, green light, red light, and infrared light at a maximum absorption wavelength (λ ) of the absorption spectrum. max ) is present in any one of the wavelength regions of about 380 nm or more and less than 500 nm, about 500 nm to 600 nm, more than about 600 nm and less than 700 nm, and more than about 700 nm to 3,000 nm, and the absorption spectrum within the wavelength region is significantly higher than the absorption spectra of the other wavelength regions. Here, significantly higher means that, for example, about 70% to 100%, about 75% to 100%, about 80% to 100%, about 85% to 100%, about 90% to 100%, or about 95% to 100% of the total area of ​​the absorption spectrum belongs to the wavelength region.

[0038] The photoelectric conversion layer 30 includes a first material and a second material forming a pn junction, and the first material and the second material receive light from the outside to generate excitons, and then separate the generated excitons into holes and electrons. For example, the first material is a p-type material, and the second material is an n-type material.

[0039] As an example, the first material and the second material are each a light absorbing material, for example, at least one of the first material and the second material is an organic light absorbing material. As an example, at least one of the first material and the second material is a wavelength-selective light absorbing material that selectively absorbs light in a predetermined wavelength range, for example, at least one of the first material and the second material is a wavelength-selective organic light absorbing material. The absorption spectra of the first material and the second material may have maximum absorption wavelengths (λ ) in the same or different wavelength ranges. max ).

[0040] For example, the absorption spectrum of the first material and the second material may each independently selectively absorb any one of blue light, green light, red light, and infrared light, and the maximum absorption wavelength (λ ) of the absorption spectrum of the first material or the second material may be determined. max ) is present in any one of the wavelength regions of about 380 nm or more and less than 500 nm, about 500 nm to 600 nm, more than about 600 nm to 700 nm, and more than about 700 nm to 3,000 nm.

[0041] In one example, the first material and / or the second material is an organic material.

[0042] In one example, the first substance and / or the second substance are small molecule compounds.

[0043] In one example, the first substance and / or the second substance are vaporizable compounds.

[0044] In one example, the first substance is an organic substance 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 represented by, for example, the following chemical formula A, but is not limited thereto.

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

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

[0048] As an example, the first substance represented by chemical formula A is represented by, but is not limited to, the following chemical formula A-1:

[0049] [ka]

[0050] In the above chemical formula A-1, X 1 are O, S, Se, Te, SO, and SO 2 , SiR a R b , or GeR c R d and Ar 1 represents 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 independently represents 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 1a and Ar 2a each independently exists or combines with each other to form a fused ring, R 1 ~R 3 and R a ~R dare 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.

[0051] As an example, Ar in chemical formula A-1 1a and Ar 2a each independently represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenanthrenyl 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, a substituted or unsubstituted naphthyl group, a naphthyridinyl group, a substituted or unsubstituted cinnolinyl group, a substituted or unsubstituted quinazolinyl group, a substituted or unsubstituted phthalazinyl group, a substituted or unsubstituted benzotriazinyl group, a substituted or unsubstituted pyridopyrazinyl group, a substituted or unsubstituted pyridopyrimidinyl group, or a substituted or unsubstituted pyridopyridazinyl group.

[0052] As an example, Ar in chemical formula A-1 1a and Ar 2a are condensed together to form a ring, and Ar 1a and Ar 2a is, for example, a single bond, -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 are linked together to form a ring, 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; 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 are each present independently or are linked to each other to form a ring.

[0053] As an example, the first substance represented by chemical formula A-1 is represented by, for example, the following chemical formulas A-2 to A-5, but is not limited thereto.

[0054] [ka]

[0055] In the above chemical formulas A-2 to A-5, X 1 and R 1 ~R 3 is as described above, Ar 3 represents 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 is a single bond, -O-, -S-, -Se-, -Te-, -N=, -NR e -, -(CRf 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 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; 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 exists or are joined 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 each independently represents 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 exists, or two adjacent ones are linked to each other to form a fused ring, R 7a~R 7e exist independently, or adjacent two of them are linked to each other to form a fused ring.

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

[0057] The second material can be, for example, organic, inorganic, and / or organic-inorganic, such as, but not limited to, a thiophene or thiophene derivative, a fullerene or a fullerene derivative.

[0058] The photoelectric conversion layer 30 further includes a third material. The third material is a material different from the first material and the second material, respectively, and is a dopant that modifies the physical properties of the first material and / or the second material in the photoelectric conversion layer 30.

[0059] The third material is mixed with the first material and the second material and arranged to contact the first material and / or the second material on an atomic scale to change the morphology of the first material and / or the second material forming a pn junction or the molecular conformation of the first material and the second material. As a result, the diversity of the morphology and molecular conformation of the photoelectric conversion layer 30 including the first material, the second material, and the third material is different from the diversity of the morphology and molecular conformation of the thin film made of the first material and the second material.

[0060] According to a quantum calculation based on such morphology, a third material having a high dipole moment changes the distribution of energy levels of the first material and / or the second material. As an example, a third material having a high dipole moment changes the distribution of HOMO energy levels or LUMO energy levels of the first material or the second material. As a result, the distribution of HOMO energy levels or the distribution of LUMO energy levels of the photoelectric conversion layer 30 including the first material, the second material, and the third material (without the third material) is different from the distribution of HOMO energy levels or the distribution of LUMO energy levels of a thin film made of the first material and the second material.

[0061] The dipole moment of the third material is, for example, about 5.5 Debye or more, 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, 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 material having a high dipole moment as a dopant, so that the first material or the second material is adjusted to have a HOMO energy level distribution or a LUMO energy level distribution in a desired region, or is adjusted to have no HOMO energy level distribution or LUMO energy level distribution in an undesired region.

[0063] For example, if the first material is a p-type material and the second material is an n-type material, the third material is a p-type material that modifies the distribution of the HOMO energy levels of the first material. For example, the distribution of the HOMO energy levels of the first material modified by the third material shifts toward a deeper HOMO energy level compared to the original distribution of the HOMO energy levels of the first material.

[0064] In this way, by shifting the distribution of the HOMO energy levels of the p-type semiconductor, it is possible to increase a desired region in the distribution of the HOMO energy levels or reduce or eliminate an undesired region in the distribution of the HOMO energy levels. For example, it is possible to reduce or eliminate a shallow HOMO energy level region in which there are relatively many trap sites for charges (e.g., holes) in the distribution of the HOMO energy levels of the p-type material, for example, it is possible to reduce or eliminate a HOMO energy level region shallower than about 5.2 eV in the distribution of the HOMO energy levels of the p-type semiconductor.

[0065] As an example, the distribution of the HOMO energy level of the first material modified by the third material is shifted toward a deeper HOMO energy level. At this time, the HOMO energy level of the third material is deeper or shallower than the HOMO energy level of the first material. For example, the HOMO energy level of the third material is deeper or shallower than the HOMO energy level of the first material by about 0.3 eV or less, for example, the HOMO energy level of the third material is in the range of about -0.3 eV to 1.2 eV (excluding 0 eV) compared to the HOMO energy level of the first material. For example, the original HOMO energy level of the first material is about 5.0 eV to 5.8 eV, and the HOMO energy level of the third material is about 4.7 eV to 6.2 eV. For example, the HOMO energy level of the third material is deeper than the HOMO energy level of the first material, for example, the original HOMO energy level of the first material is about 5.0 eV to 5.8 eV, and the HOMO energy level of the third material is about 5.1 eV to 6.2 eV. The HOMO energy level of the first material modified by the third material is deeper than the HOMO energy level of the first material. For example, the HOMO energy level of the first material modified by the third material may be 0.001 eV deeper than the HOMO energy level of the first material, and may be 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 0.0 eV, or about 0.005 eV to 0.018 eV deeper within the above range.

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

[0067] As a result, the HOMO energy level of the photoelectric conversion layer 30 containing the first material, the second material, and the third material (without the third material) is deeper than the HOMO energy level of a thin film made of the first material and the second material. For example, the HOMO energy level of the photoelectric conversion layer 30 (without the third material) is deeper than the HOMO energy level of a thin film made of the first material and the second material by about 0.001 eV or more, for example, by 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, or about 0.005 eV to 0.018 eV.

[0068] The third material is an organic material, an inorganic material, and / or an organic-inorganic material exhibiting the above-mentioned characteristics, for example, an organic material, for example, a low molecular weight compound, for example, an evaporative organic compound. As an example, the photoelectric conversion layer 30 is a co-evaporated thin film of the first material, the second material, and the third material.

[0069] The third material is, for example, a light absorbing material that selectively absorbs any one of light in the blue wavelength region, the green wavelength region, the red wavelength region, and the infrared wavelength region.

[0070] For example, the absorption spectra of the first and third materials may have a maximum absorption wavelength (λ ) that commonly belongs to one of a blue wavelength region, a green wavelength region, a red wavelength region, and an infrared wavelength region. max As an example, the absorption spectra of the first and third substances each have a maximum absorption wavelength (λ ) in the blue wavelength region of about 380 nm or more and less than 500 nm. max As an example, the absorption spectra of the first and third substances each have a maximum absorption wavelength (λ ) in the green wavelength region of about 500 nm to 600 nm. max As an example, the absorption spectra of the first and third substances each have a maximum absorption wavelength (λ ) in the red wavelength region of more than about 600 nm and less than about 700 nm. max For example, the absorption spectra of the first and third substances each have a maximum absorption wavelength (λ ) in the infrared wavelength region of about 700 nm to about 3,000 nm. max ).

[0071] The third substance is, for example, represented by the following Chemical Formula 1, but is not limited thereto.

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

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

[0074] As an example, HA3 may be the same as or different from HA1 described above, EDM3 may be the same as or different from EDM1 described above, and EAM3 may be the same as or different from EAM1 described above, provided that at least one of HA3, EDM3, and EAM3 is different from HA1, EDM1, or EAM1.

[0075] As an example, the third substance represented by Chemical Formula 1 may be represented by, but is not limited to, the following Chemical Formula 1-1:

[0076] [ka]

[0077] In the above chemical formula 1-1, X 2 are O, S, Se, Te, SO, and SO 2 , SiR a R b , or GeR c R d and Ar 2 represents 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 independently represents 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 fused ring, R 4 ~R 6 and R a ~R d 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.

[0078] As an example, Ar in Chemical Formula 1-1 1b and Ar 2bare each 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 phenanthrenyl 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, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted cinnolinyl group, a substituted or unsubstituted quinazolinyl group, a substituted or unsubstituted phthalazinyl group, a substituted or unsubstituted benzotriazinyl group, a substituted or unsubstituted pyridopyrazinyl 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 are condensed together to form a ring, and Ar 1b and Ar 2b is, for example, a single bond, -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 are linked together to form a ring, 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; 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 are each present independently or are linked to each other to form a ring.

[0080] As an example, the third substance represented by chemical formula 1-1 is represented by, for example, the following chemical formulas 1-2 to 1-7, but is not limited thereto.

[0081] [ka]

[0082] In the above chemical formulas 1-2 to 1-7, X 2 and R 4 ~R 6 is as described above, Ar 4 represents 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 is a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, Z is a single bond, -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 where R e ~R oare 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 12 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, 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 each independently exists or are joined to each other to form a ring, Y 3 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 6f ~R 6j , R 7f ~R 7j , R 18 and R 19 each independently represents 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 6f ~R 6j each independently exists, or two adjacent ones are linked to each other to form a fused ring, R 7f ~R 7j exist independently, or adjacent two of them are linked to each other to form a fused ring.

[0083] As an example, Ar in formula 1-2, 1-4, or 1-6 4 is benzene, naphthalene, anthracene, thiophene, selenophene, tellurophene, pyridine, pyrimidine, or two or more fused rings selected from among these.

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

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

[0086] The third material is included in an amount that does not affect the molecular stability of the first material and the second material and other physical properties required for the photoelectric conversion layer 30, in addition to modifying the physical properties of the first material and / or the second material, and is included in an amount that is less than that of the first material or the second material, for example. For example, the third material is included in an amount of about 30 volume % or less based on the total volume of the first material and the third material, and is included in an amount within the above range of about 1 to 30 volume %, about 1 to 25 volume %, about 1 to 20 volume %, about 1 to 15 volume %, or about 1 to 10 volume %.

[0087] As an example, the photoelectric conversion layer 30 is a ternary system made up of the first material, the second material, and the third material described above.

[0088] The photoelectric conversion element 100 further includes an antireflection layer (not shown) disposed on one side of the first electrode 10 or the second electrode 20. The antireflection layer is disposed on the light incident side to reduce the reflectivity of the incident light, thereby further improving the light absorbency. For example, when light is incident on the first electrode 10 side, the antireflection layer is disposed on one side of the first electrode 10, and when light is incident on the second electrode 20 side, the antireflection layer is disposed on one side of the second electrode 20.

[0089] The anti-reflection layer includes a material having a refractive index of, for example, about 1.6 to 2.5, and includes at least one of a metal oxide, a metal sulfide, and an organic material having a refractive index in the above range. Examples of the anti-reflection layer include, but are 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 materials such as amine derivatives.

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

[0091] At this time, as described above, the photoelectric conversion layer 30 may further include a third material that modifies the properties of the first and / or second materials in addition to the first and second materials that form the pn junction, thereby realizing desired properties or eliminating undesired properties. This may improve the optical and electrical properties of the photoelectric conversion element 100. As an example, as described above, the distribution of the energy levels of the first or second material may be adjusted to reduce or eliminate an energy level region (e.g., a shallow HOMO energy level region) in which there are relatively many trap sites for charges in the photoelectric conversion layer 30, thereby reducing or preventing remaining charges that remain at trap sites in charges that move from the photoelectric conversion layer 30 to the first electrode 10 and / or the second electrode 20. In this way, image retention due to residual charges accumulated in the photoelectric conversion layer 30 may be reduced or prevented, thereby improving the electrical performance of the photoelectric conversion element 100.

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

[0093] 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 above-described embodiment. However, unlike the above-described embodiment, 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) may be, but are not limited to, a hole injecting layer (HIL) that facilitates hole injection, a hole transporting layer (HTL) that facilitates hole transport, an electron blocking layer (EBL) that blocks electron transport, an electron injecting layer (EIL) that facilitates electron injection, an electron transporting layer (ETL) that facilitates electron transport, and / or a hole blocking layer (HBL) that blocks hole transport.

[0095] The sublayers (40, 50) each independently comprise organic, inorganic, and / or organic-inorganic.

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

[0097] For example, one of the auxiliary layers (40, 50) includes an organic auxiliary layer, which includes, but is not limited to, a compound represented by the following Formula 2A or 2B:

[0098] [ka]

[0099] In the above chemical formula 2A or 2B, M 1 and M 2 are each independently O, S, Se, Te, or CR q R r , SiR s R t , or NR u and Ar 1c , Ar 2c , Ar 3c , and Ar 4c each independently represents 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 are each independently a single bond, -(CR v R w ) n3 -, -O-, -S-, -Se-, -Te, -N=, -NR x - or -SiR y R z -, where n3 is 1 or 2; R 30 ~R 37 and R q ~R z 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 heterocyclic group having 3 to 30 carbon atoms, halogen, or a cyano group.

[0100] As an example, the organic auxiliary layer is a compound represented by the following formula 2A-1 or 2B-1, but is not limited thereto.

[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 is as described above, R 38 ~R 45are 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.

[0103] As an example, the organic auxiliary layer is a compound represented by the following formula 2A-1a or 2B-1a, but is not limited thereto.

[0104] [ka]

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

[0106] As an example, one of the sublayers (40, 50) is an inorganic sublayer and the other of the sublayers (40, 50) is an organic sublayer. As an example, one of the auxiliary layers (40, 50) may be omitted.

[0107] The above-mentioned photoelectric conversion element 100 is applied to a sensor, for example, and the sensor is, for example, an image sensor. The image sensor to which the above-mentioned photoelectric conversion element 100 is applied is applied to an image sensor suitable for high-speed shooting by reducing image lag caused by residual charges.

[0108] An example of an image sensor to which the above-described element is applied will be described below with reference to the drawings. As an example of the image sensor, an organic CMOS image sensor will be described.

[0109] FIG. 3 is a cross-sectional view illustrating an example of an image sensor according to an embodiment.

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

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

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

[0113] An insulating layer 80 is formed over the metal lines and pads. The insulating layer 80 is made of an inorganic insulating material such as silicon oxide and / or silicon nitride, or a low K material such as SiC, SiCOH, SiCO, and SiOF. The insulating layer 80 has a trench 85 exposing the charge reservoir 155. The trench 85 is filled with a filling material.

[0114] A photoelectric conversion element 100 is formed on the insulating layer 80. The photoelectric conversion element 100 has the structure shown in Fig. 1 or 2, and the specific description is as described above. One of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is a light receiving 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 reservoir 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 in the blue pixel, a red filter 70b formed in the red pixel, and a green filter 70c formed in the green pixel, but is not limited thereto, and may alternatively or additionally include a cyan filter, a magenta filter, and / or a yellow filter.

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

[0117] A condenser lens (not shown) is further formed on the color filter layer 70. The condenser lens controls the direction of the incident light to focus the light at one point. The condenser lens is, for example, cylindrical or hemispherical, but is not limited thereto.

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

[0119] 4 and 5, the image sensor 400 according to this embodiment includes a semiconductor substrate 110 in which photo-sensing elements (150a, 150b), transfer transistors (not shown), and charge storage elements 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, and integrates the light sensing elements (150a, 150b), a transfer transistor (not shown), and a charge reservoir 155. The light sensing elements (150a, 150b) are photodiodes.

[0121] The light sensing element (150a, 150b), the transfer transistor, and / or the charge reservoir 155 are integrated per pixel, and as an example, as can be seen from the drawing, the light sensing element (150a, 150b) is included in the blue pixel and the red pixel, respectively, and the charge reservoir 155 is included in the green pixel.

[0122] The photo-sensing elements 150a and 150b sense light, and the sensed information is transferred by a transfer transistor. The charge storage 155 is electrically connected to the photoelectric conversion element 100, and the information of the charge storage 155 is transferred by the transfer transistor.

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

[0124] A lower insulating layer 60 is formed over the metal lines 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 a trench 85 exposing the charge reservoir 155. The trench 85 is filled with a filling 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 in the blue pixel and a red filter 70b formed in the red pixel. However, the color filter layer 70 is not limited thereto and may include a cyan filter, a magenta filter, and / or a yellow filter instead or in addition. Although an example in which a green filter is not provided will be described in this embodiment, a green filter may be provided in some cases.

[0126] An upper insulating layer 80 is formed on the color filter layer 70. The upper insulating layer 80 is formed to remove and planarize steps caused by the color filter layer 70. The upper insulating layer 80 and the lower insulating layer 60 have contact holes (not shown) exposing pads and trenches 85 exposing charge reservoirs 155 of 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 Fig. 1 or 2, and the specific description is as described above. One of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is a light receiving 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 reservoir 155.

[0128] A condenser lens (not shown) is further formed on the photoelectric conversion element 100. The condenser lens controls the direction of the incident light to condense the light at one point. The condenser lens is, for example, cylindrical or hemispherical, but is not limited thereto.

[0129] FIG. 6 is a cross-sectional view showing another example of the image sensor of FIG.

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

[0131] However, in the image sensor 500 according to the present embodiment, unlike the above-mentioned embodiments, the photo-sensing elements 150a, 150b are stacked vertically, and the lower insulating layer 60 and the color filter layer 70 are omitted. The photo-sensing elements 150a, 150b are electrically connected to a charge reservoir (not shown) and transmitted by a transfer transistor. The photo-sensing elements 150a, 150b selectively absorb light of each wavelength range depending on the stacking depth.

[0132] The photoelectric conversion element 100 has the structure shown in Fig. 1 or 2, and the specific description is as described above. One of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 is a light receiving 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 reservoir 155.

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

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

[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 transfer transistors (not shown) and charge reservoirs (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] On the lower insulating layer 60, a first photoelectric conversion element 100a, a second photoelectric conversion element 100b, and a third photoelectric conversion element 100c are formed in sequence.

[0139] The first, second, and third photoelectric conversion elements (100a, 100b, 100c) each have the structure shown in Fig. 1 or 2 independently, and the specific description is as described above. One of the first electrode 10 and the second electrode 20 of the first, second, and third photoelectric conversion elements (100a, 100b, 100c) is a light receiving 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, 100c) is connected to the charge storage (155a, 155b, 155c).

[0140] The first photoelectric conversion element 100a selectively absorbs light in any one of the wavelength regions 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] On the intermediate insulating layer 65, the second photoelectric conversion element 100b is formed.

[0142] The second photoelectric conversion element 100b selectively absorbs light in any one of the wavelength regions of red, blue, and green and performs photoelectric conversion. 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) exposing the charge reservoirs (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 any one of the wavelength regions of red, blue, and green and performs photoelectric conversion. For example, the third photoelectric conversion element 100c is a green photoelectric conversion element.

[0145] A condenser lens (not shown) is further formed on the third photoelectric conversion element 100c. The condenser lens controls the direction of the incident light to condense the light to one point. The condenser lens is, for example, cylindrical or hemispherical, but is not limited thereto.

[0146] Although the drawings show 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 order, the stacking order is not limited thereto and may be changed in various ways.

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

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

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

[0150] Each of the photoelectric conversion elements (90-1, 90-2, 90-3) is one of the photoelectric conversion elements (100, 200) described above. As an example, the 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). As an example, the multiple photoelectric conversion elements (90-1, 90-2, 90-3) share a common first electrode 10 and / or a common second electrode 20. As an example, the 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 the incident light. Other structures of the image sensor 1100 are similar to one or more of the image sensors described in Figures 3 to 8.

[0151] FIG. 11 is a cross-sectional view illustrating an example of an image sensor according to an embodiment.

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

[0153] As an example, the photoelectric conversion element 91 includes a plurality of photoelectric conversion elements arranged in a horizontal direction, each absorbing light in a different wavelength region. As an example, the photoelectric conversion element 91 photoelectrically converts light in one wavelength region selected from blue light, green light, and red light. As an example, the photoelectric conversion element 91 entirely or partially overlaps the photoelectric conversion element 90-1. Other structures of the image sensor 1200 are similar to one or more of the image sensors described in FIGS. 3 to 8.

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

[0155] 12, the image sensor 1300 includes a semiconductor substrate 110 on which photo-sensing elements (150a, 150b), transfer transistors (not shown), and charge storages 155 are integrated; an upper insulating layer 80 and a color filter layer 70 located on the upper portion of the semiconductor substrate 110; a lower insulating layer 60 and a photoelectric conversion element 90 located on the lower portion of the semiconductor substrate 110. The photoelectric conversion element 90 is the above-mentioned photoelectric conversion element (100, 200). In FIG. 12, the photoelectric conversion element 90 is disposed on the lower portion of the semiconductor substrate 110, so that the photoelectric conversion element 90 and the color filter layer 70 are disposed separately from the photo-sensing elements (150a, 150b). Other structures of the image sensor 1300 are similar to one or more of the image sensors described with reference to FIGS. 3 to 8.

[0156] The above-mentioned photoelectric conversion elements and sensors are each applicable to a variety of electronic devices, such as, but not limited to, mobile phones, cameras, biometric recognition devices, and / or automotive electrical components.

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

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

[0159] The above-mentioned embodiments will be described in more detail with reference to the following examples, which are merely for illustrative purposes and are not intended to limit the scope of the present invention.

[0160] <Simulation evaluation>

[0161] (1) Examples and Comparative Examples

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

[0163] The quantum calculation takes into account the conformation and surrounding environment of each molecule in the morphology, and evaluates the distribution of energy levels taking into account the conformational changes of the first substance or the environmental changes of the molecule in response to the influence of a third substance.

[0164] [Table 1]

[0165] [ka]

[0166] (2) Evaluation of the physical properties of materials

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

[0168] The HOMO energy level distribution was simulated using Quantumpatch software (Nanomatch GmbH), and the molecular dipole moment was simulated using Jaguar software (Schrodinger, LLC., Materials science suite). Note that Quantumpatch software is B3LYP / def2-SVP, and Jaguar_software is LACV3P. ** Density Functional Theory (DFT) calculations are performed using the basis set.

[0169] [Table 2]

[0170] (3) Simulation Results I

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

[0172] FIG. 14 is a graph showing a change in the distribution of the HOMO energy level of the first substance, and FIGS. 15 and 16 are graphs showing a change in the residual charge according to the change in the distribution of the HOMO energy level of the first substance.

[0173] 14 to 16, it can be expected that the characteristics of the residual charge are improved as the distribution of the HOMO energy level of the first material moves deeper.

[0174] (4) Simulation Results II

[0175] The change in the energy level of the first substance and the accompanying change 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 can be expected that the deeper the HOMO energy level of the first material, the more the residual charge characteristics will be improved, and that the greater the change in the HOMO energy level of the first material, the more the residual charge characteristics will be improved.

[0179] <Element evaluation>

[0180] (1) Fabrication of the element

[0181] The following photoelectric conversion element will be fabricated to experimentally verify the simulation evaluation.

[0182] <Element Example 1>

[0183] ITO was laminated on a glass substrate by sputtering to form an anode having a thickness of 150 nm. Next, the following compound A was deposited on the anode to form a charge blocking layer having a thickness of 5 nm. Next, a compound represented by the following formula B (first substance) (λ max :545nm), fullerene (C 60 ) (second substance), and compound C-1 (third substance) (λ max A photoelectric conversion layer having a thickness of 100 nm was formed by co-evaporating the first and second materials at a volume ratio of 1:1, and the third material was co-evaporated to account for 5 volume % of the total volume of the first and third materials. The modified HOMO energy level of the first material in the photoelectric conversion layer is 5.495 eV, and the LUMO energy level of fullerene is 3.563 eV. Next, Yb was thermally evaporated on the photoelectric conversion layer to form an electron buffer layer (WF: 2.6 eV) having a thickness of 1.5 nm. Next, ITO was sputtered on the electron buffer layer to form a cathode having a thickness of 7 nm. Next, aluminum oxide (Al 2 O 3 ) was evaporated to form an antireflection layer with a thickness of 50 nm, and the resulting material was sealed with a glass plate to produce a photoelectric conversion element.

[0184] [ka]

[0185] <Element Example 2>

[0186] As a third substance, compound C-2 (λ max A photoelectric conversion element was manufactured in the same manner as in element example 1, except that a photoelectric conversion layer was formed using a 1000 nm wavelength (538 nm). The modified HOMO energy level of the first material in the photoelectric conversion layer was 5.502 eV.

[0187] <Element Example 3>

[0188] As the third substance, compound C-3 (λ max A photoelectric conversion element was manufactured in the same manner as in element example 1, except that a photoelectric conversion layer was formed using a 1000 nm wavelength (540 nm) 1000 nm wavelength. The modified HOMO energy level of the first material in the photoelectric conversion layer was 5.508 eV.

[0189] <Comparative element example 1>

[0190] A photoelectric conversion element was manufactured in the same manner as in element example 1, except that the photoelectric conversion layer was formed by co-evaporating the first and second materials without including the third material. The deformed HOMO energy level of the first material in the photoelectric conversion layer is 5.490 eV.

[0191] <Comparative element example 2>

[0192] As the third substance, compound C-4 (λ max A photoelectric conversion element was manufactured in the same manner as in element example 1, except that a photoelectric conversion layer was formed using a 1000 nm wavelength (534 nm) 1000 nm wavelength. The deformed HOMO energy level of the first material in the photoelectric conversion layer was 5.479 eV.

[0193] <Comparative element example 3>

[0194] A photoelectric conversion element was manufactured in the same manner as in element example 1, except that a photoelectric conversion layer was formed using compound C-5 instead of compound C-1 as the third material. The modified HOMO energy level of the first material in the photoelectric conversion layer is 5.482 eV.

[0195] (3) Evaluation

[0196] The remaining charge characteristics of the photoelectric conversion elements according to the element example and the element comparative example were evaluated.

[0197] The residual charge characteristic refers to the amount of charge that remains after photoelectric conversion in one frame without being used for signal processing and that is read in the next frame. The elements according to the embodiment and the comparative example were irradiated with light in the green wavelength region where photoelectric conversion occurs for 33 milliseconds, and after the light was turned off, the amount of charge remaining in the previous frame was measured by a Keithley 2400 device. -6 It is evaluated based on the amount of current measured in seconds. The amount of residual electrons is h+ / s / μm at 5,000 lux. 2 Evaluate by unit.

[0198] The results are shown in Table 4.

[0199] [Table 4]

[0200] Referring to Table 4, it was confirmed that the device according to the device example had improved residual electron characteristics compared to the device according to the device comparative example, and the device example produced results substantially similar to the above-mentioned simulation results.

[0201] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the above-described embodiments and can be modified 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 insulation layer 70 color filter layers 70a, 70b, 70c Blue, red, green filters 80 (Top) Insulation layer 85, 85a, 85b, 85c trenches 90, 90-1, 90-2, 90-3, 91, 100 Photoelectric conversion element 100a, 100b, 100c First to third photoelectric conversion elements 110 Semiconductor substrate 110a surface 150a, 150b, 150c Light sensing element 155, 155a, 155b, 155c charge reservoir 180 Insulating Film 300, 400, 500, 600, 1100, 1200, 1300 Image Sensor 1700 Electronic equipment 1710 Bus 1720 Processor 1730 Memory 1740 Image Sensor

Claims

1. A photoelectric conversion layer is provided between a first electrode, a second electrode, and the first electrode and the second electrode. the photoelectric conversion layer comprises a mixture of a first material, a second material, and a third material, each of which is different from the other; The first material and the third material are light absorbing materials having a maximum absorption wavelength in a first wavelength region selected from a blue wavelength region, a green wavelength region, a red wavelength region, and an infrared wavelength region; the dipole moment of the third material is 5.5 Debye or more; A photoelectric conversion element, wherein the third material is contained in an amount of 30 volume % or less with respect to a total volume of the first material and the third material.

2. the first material and the third material are p-type materials; The photoelectric conversion element according to claim 1 , wherein the second material is an n-type material.

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

4. the HOMO energy level of the third material is 4.7 eV to 6.2 eV; 2. The photoelectric conversion element according to claim 1, wherein the HOMO energy level of the first substance is 5.0 eV to 5.8 eV.

5. the HOMO energy level of the third material is 5.1 eV to 6.0 eV; 5. The photoelectric conversion element according to claim 4, wherein the HOMO energy level of the first substance is 5.0 eV to 5.8 eV.

6. 2. The photoelectric conversion element according to claim 1, wherein the third material is contained in an amount of 1 to 10% by volume with respect to a total volume of the first material and the third material.

7. 2. The photoelectric conversion element according to claim 1, wherein the photoelectric conversion layer is a three-component system including the first substance, the second substance, and the third substance.

8. 2. The photoelectric conversion element according to claim 1, wherein the third material is represented by the following chemical formula 1-1: 【Chemistry 1-1】 In the above Chemical Formula 1-1, X ２ is O, S, Se, Te, SO, SO ２ , SiR ａ R ｂ , or GeR ｃ R ｄ and Ar ２ represents 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 a combination of two or more fused rings selected from these, Ar １ｂ and Ar ２ｂ each independently represents 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 fused ring, R ４ ~R ６ and R ａ ~R ｄ 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.

9. The photoelectric conversion element according to claim 1, wherein the first substance is represented by the following chemical formula A-1: 【Chemical A-1】 In the above chemical formula A-1, X １ is O, S, Se, Te, SO, SO ２ , SiR ａ R ｂ , or GeR ｃ R ｄ and Ar １ represents 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 a combination of two or more fused rings selected from these, Ar １ａ and Ar ２ａ each independently represents 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 １ａ and Ar ２ａ each independently exists or combines with each other to form a fused ring, R １ ~R ３ and R ａ ~R ｄ 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.

10. 2. The photoelectric conversion element according to claim 1, wherein the second substance includes an inorganic substance, a thiophene or a thiophene derivative, a fullerene or a fullerene derivative, or a combination thereof.

11. A sensor comprising the photoelectric conversion element according to claim 1 .

12. An electronic device comprising the sensor of claim 11.

13. An electronic device comprising the photoelectric conversion element according to claim 1 .

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