Photoelectric conversion elements, organic sensors and electronic devices

Abstract

To provide a photoelectric conversion element, an organic sensor, and an electronic device, in which the charge extraction efficiency is improved.SOLUTION: A photoelectric conversion element according to the present invention includes a first electrode and a second electrode that face each other, a photoelectric conversion layer that exists between the first electrode and the second electrode, absorbs light in at least some wavelength regions, and converts the light into electric signals, and an organic assistance layer that exists between the first electrode and the photoelectric conversion layer and has a higher charge transfer degree than that of the photoelectric conversion layer. The photoelectric conversion layer includes a first organic substance. The organic assistance layer includes a second organic substance that is different from the first organic substance. The second organic substance is a condensed polycyclic aromatic compound, a condensed polycyclic heteroaromatic compound, or a combination of these. The condensed polycyclic aromatic compound or the condensed polycyclic heteroaromatic compound is a condensation of four or more cycles.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Photoelectric conversion elements are elements that receive light and convert it into an electrical signal, and include photodiodes and phototransistors, and are applied to organic sensors, photodetectors, solar cells, and the like.

[0003] Organic sensors are required to have higher resolution, and as a result, pixel size is becoming smaller. In the case of silicon photodiodes, which are currently the predominant type, sensitivity can decrease as the absorption area decreases as pixel size becomes smaller. As a result, organic materials that can replace silicon are being researched.

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

[0005] However, organic materials may exhibit properties different from those of 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 devices. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-011273 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 with improved charge extraction efficiency, an organic sensor including the photoelectric conversion element, and an electronic device including the photoelectric conversion element or the organic 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 and a second electrode facing each other, a photoelectric conversion layer located between the first electrode and the second electrode and absorbing light in at least a certain wavelength range and converting it into an electrical signal, and an organic auxiliary layer located between the first electrode and the photoelectric conversion layer and having a charge mobility higher than that of the photoelectric conversion layer, wherein the photoelectric conversion layer contains a first organic material, and the organic auxiliary layer contains a second organic material different from the first organic material, and the second organic material is a condensed polycyclic aromatic compound, a condensed polycyclic heteroaromatic compound, or a combination thereof, and the condensed polycyclic aromatic compound or the condensed polycyclic heteroaromatic compound has four or more fused rings.

[0009] The charge mobility of the organic auxiliary layer may be 100 times or more higher than the charge mobility of the photoelectric conversion layer. The charge mobility of the second organic material may be about 100 times or more higher than the charge mobility of the first organic material. The charge mobility of the second organic material is 1.0×10 -3 cm 2 / Vs or more. The fused polycyclic heteroaromatic compound can include S, Se, Te, or a combination thereof. The photoelectric conversion layer may further include a p-type semiconductor or an n-type semiconductor that forms a pn junction with the first organic material, and the organic auxiliary layer may further include the p-type semiconductor or the n-type semiconductor. The p-type semiconductor or the n-type semiconductor may include a fullerene or a fullerene derivative. The organic help layer may have a thickness of about 5 nm or less. The photoelectric conversion element may further include an inorganic nanolayer located between the first electrode and the photoelectric conversion layer. The inorganic nanolayer can include a lanthanum group element, calcium (Ca), potassium (K), aluminum (Al), or an alloy thereof. The lanthanum group element may include ytterbium (Yb). The inorganic nanolayer can have a thickness of about 5 nm or less. The organic auxiliary layer may be in contact with the photoelectric conversion layer, and the inorganic nanolayer may be in contact with the first electrode. The first electrode may be a cathode and the second electrode may be an anode.

[0010] In order to achieve the above object, an organic sensor according to one aspect of the present invention includes the photoelectric conversion element.

[0011] 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 organic sensor. [Effects of the Invention]

[0012] According to the present invention, the charge extraction efficiency of a photoelectric conversion element can be increased by improving charge mobility and reducing residual charges. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view showing an example of a photoelectric conversion element according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a cross-sectional view showing an example of a photoelectric conversion element according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a cross-sectional view showing an example of a photoelectric conversion element according to a third embodiment of the present invention. [Figure 4] FIG. 10 is a cross-sectional view showing an example of a photoelectric conversion element according to a fourth embodiment of the present invention. [Figure 5] 1 is a cross-sectional view schematically illustrating an example of an organic sensor according to an embodiment of the present invention. [Figure 6]FIG. 1 is a cross-sectional view schematically illustrating another example of an organic sensor according to an embodiment of the present invention. [Figure 7] FIG. 1 is a plan view schematically illustrating an example of an organic sensor according to an embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view schematically illustrating an example of the organic sensor of FIG. [Figure 9] FIG. 8 is a cross-sectional view schematically showing another example of the organic sensor of FIG. [Figure 10] FIG. 10 is a cross-sectional view schematically illustrating an example of an organic sensor according to another embodiment of the present invention. [Figure 11] FIG. 10 is a cross-sectional view schematically illustrating another example of an organic sensor according to another embodiment of the present invention. [Figure 12] FIG. 10 is a plan view schematically illustrating an example of an organic sensor according to another embodiment of the present invention. [Figure 13] FIG. 13 is a cross-sectional view schematically illustrating an example of the organic sensor of FIG. [Figure 14] FIG. 13 is a cross-sectional view schematically showing another example of the organic sensor of FIG. [Figure 15] 1 is a plan view schematically illustrating an organic CMOS image sensor according to an embodiment of the present invention. [Figure 16] FIG. 16 is a cross-sectional view showing an example of the organic CMOS image sensor of FIG. [Figure 17] FIG. 10 is a cross-sectional view showing another example of an organic CMOS image sensor. [Figure 18] FIG. 10 is a cross-sectional view showing yet another example of an organic CMOS image sensor. [Figure 19] 1 is a schematic block diagram of an electronic device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, specific examples of embodiments of the present invention will be described in detail with reference to the drawings. However, the structures actually applied may be realized in various different forms and are not limited to the embodiments described herein.

[0015] In the drawings, the thickness of layers and regions is exaggerated to clearly show them.

[0016] When a layer, film, region, plate, or other part is said to be 'on' another part, this includes not only when it is 'directly on' that other part, but also when there is another part between them. On the other hand, when a part is said to be 'directly on' another part, it means that there is no other part between them.

[0017] Unless otherwise defined in this specification, "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 group 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 1 to 20 carbon atoms, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkyl group having 2 ... It means that the group is substituted with a substituent selected from an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 20 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms, a heteroarylalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a cycloalkenyl group having 3 to 15 carbon atoms, a cycloalkynyl group having 6 to 15 carbon atoms, a heterocycloalkyl group having 3 to 30 carbon atoms, and combinations thereof.

[0018] Unless otherwise defined herein, the term "hetero" refers to a group containing 1 to 4 heteroatoms selected from N, O, S, Se, Te, Si, and P.

[0019] As used herein, 'combination' includes mixtures and laminated structures of two or more materials.

[0020] As used herein, 'metal' includes metals, metalloids, or combinations thereof.

[0021] As used herein, an 'energy level' refers to the highest occupied molecular orbital (HOMO) energy level or the lowest unoccupied molecular orbital (LUMO) energy level.

[0022] In this specification, 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 a large absolute value with the vacuum level being '0 eV', and a shallow, low, or small work function or energy level means a small absolute value with the vacuum level being '0 eV'.

[0023] In this specification, the charge mobility is a value evaluated using a diode structure.

[0024] Hereinafter, a photoelectric conversion element according to an embodiment of the present invention will be described.

[0025] FIG. 1 is a cross-sectional view showing an example of a photoelectric conversion element according to a first embodiment of the present invention.

[0026] Referring to FIG. 1, a photoelectric conversion element 100 according to this embodiment includes a first electrode 10, a second electrode 20, a photoelectric conversion layer 30, and an organic auxiliary layer 40.

[0027] The substrate (not shown) may be disposed on the first electrode 10 side or on the second electrode 20 side. The substrate is made of, for example, an inorganic material such as glass, an organic material such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyethersulfone, or a combination thereof, or a silicon wafer. The substrate may be omitted.

[0028] 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 a cathode, and the second electrode 20 is an anode. For example, the first electrode 10 is an anode, and the second electrode 20 is a cathode.

[0029] At least one of the first electrode 10 and the second electrode 20 is a transparent electrode. Here, the transparent electrode has a high light transmittance of about 80% or more, and does not include, for example, a semi-transparent electrode for a microcavity. The transparent electrode includes, for example, at least one of an oxide conductor and a carbon conductor. The oxide conductor is, for example, 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, for example, one or more selected from graphene and carbon nanotubes.

[0030] Either the first electrode 10 or the second electrode 20 is a reflective electrode. Here, the reflective electrode is a reflective electrode having a high reflectance, for example, a light transmittance of less than about 10% or 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.

[0031] As an example, the first electrode 10 is a transparent electrode with a light transmittance of 80% or more, or a reflective electrode with a light transmittance of less than about 10%.

[0032] The photoelectric conversion layer 30 absorbs light in at least a certain wavelength range and converts it into an electrical signal. For example, it converts a portion of light in the green wavelength range (hereinafter referred to as 'green light'), light in the blue wavelength range (hereinafter referred to as 'blue light'), light in the red wavelength range (hereinafter referred to as 'red light'), and light in the infrared wavelength range (hereinafter referred to as 'infrared light') into an electrical signal.

[0033] For example, the photoelectric conversion layer 30 selectively absorbs any one of green light, blue light, red light, and infrared light. Here, selective absorption of any one of green light, blue light, red light, and infrared light means that the photoelectric conversion layer 30 selectively absorbs any one of green light, blue light, red light, and infrared light at a peak absorption wavelength (λ max ) is present in any one of the wavelength ranges of about 500 nm to 600 nm, about 380 nm or more but less than 500 nm, about more than 600 nm but less than 700 nm, and more than about 700 nm, and the absorption spectrum in that wavelength range is significantly higher than the absorption spectra in other wavelength ranges.

[0034] The photoelectric conversion layer 30 is a layer in which at least one p-type semiconductor and at least one n-type semiconductor form a p-n junction, and upon receiving light from the outside, generates excitons, and then separates the generated excitons into holes and electrons.

[0035] The p-type semiconductor and the n-type semiconductor are each a light-absorbing material, for example, at least one of the p-type semiconductor and the n-type semiconductor is an organic light-absorbing material. As an example, at least one of the p-type semiconductor and the n-type semiconductor is a wavelength-selective light-absorbing material that selectively absorbs light in a predetermined wavelength range, for example, at least one of the p-type semiconductor and the n-type semiconductor is a wavelength-selective organic light-absorbing material. The p-type semiconductor and the n-type semiconductor have peak absorption wavelengths (λ ) in the same or different wavelength ranges. max )

[0036] As an example, a p-type semiconductor is an organic material having a core structure that includes an electron-donating moiety, a π-conjugated linking group, and an electron-accepting moiety.

[0037] The p-type semiconductor is represented by, for example, the following chemical formula 1, but is not limited thereto.

[0038] [Chemical formula 1] EDG-HA-EAG

[0039] In the above chemical formula 1, HA is a heterocyclic group having 2 to 30 carbon atoms and containing at least one of S, Se, Te, and Si; EDG is an electron donating group, EAG is an electron accepting group.

[0040] As an example, the p-type semiconductor represented by the above chemical formula 1 is represented by the following chemical formula 1A.

[0041] [ka]

[0042] In the above chemical formula 1A, X is S, Se, Te, SO, SO2, or SiR a R b and Ar 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 are each 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, Ar 1a and Ar 2a are present independently or bonded to each other to form a fused ring, R 1a ~R 3a , R a and R b are each independently hydrogen, deuterium, a substituted or unsubstituted alkyl 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 substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a cyano group.

[0043] As an example, in the above chemical formula 1A, Ar 1a and Ar 2aare each independently 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, naphthyridinyl group, substituted or unsubstituted cinnolinyl group, substituted or unsubstituted quinazolinyl group, substituted or unsubstituted phthalazinyl group, substituted or unsubstituted benzotriazinyl group, substituted or unsubstituted pyridopyrazinyl group, substituted or unsubstituted pyridopyrimidinyl group, and substituted or unsubstituted pyridopyridazinyl group.

[0044] As an example, in the above chemical formula 1A, Ar 1a and Ar 2a are condensed with each other to form a ring, and Ar 1a and Ar 2a is, for example, a single bond, -(CR g R h ) n2 -(n2 is 1 or 2), -O-, -S-, -Se-, -N=, -NR i -, -SiR j R k -, and -GeR l R m - are linked to form a ring by one selected from g ~R m are each independently hydrogen, a substituted or unsubstituted alkyl 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 substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a cyano group.

[0045] As an example, the p-type semiconductor represented by the above chemical formula 1 is represented by the following chemical formula 1B-1 or 1B-2.

[0046] [ka]

[0047] In the above chemical formula 1B-1 or 1B-2, X 1 is Se, Te, O, S, SO, or SO2, 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, R 1 ~R 3 are each independently selected from 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, a cyano group, a group containing a cyano group, and combinations thereof; G is a single bond, -O-, -S-, -Se-, -N=, -(CR f R g ) k -, -NR h -, -SiR i R j -,-GeR k R l -, -(C(R m )=C(R n ))-, and SnR o R p is selected from, where R f , R g , R h , R i , R j , R k , R l , R m , R n , R o , and R pare each independently selected from hydrogen, halogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 12 carbon atoms; R f and R g , R i and R j , R k and R l , R m and R n , and R o and R p are present independently or are joined together to form a ring, and k is 1 or 2; Y 2 are O, S, Se, Te, and C(R q )(CN)(where R q is selected from hydrogen, a cyano group (—CN), and an alkyl group having 1 to 10 carbon atoms; R 6a ~R 6d and R 7a ~R 7d , R 16 and R 17 are each independently selected from hydrogen, a substituted or unsubstituted alkyl 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, a cyano group, a group containing a cyano group, and combinations thereof; R 6a ~R 6d exist independently, or adjacent two of them are linked to each other to form a fused ring, R 7a ~R 7d are present independently, or two adjacent ones are linked to each other to form a fused ring.

[0048] As an example, in the above chemical formula 1B-1 or 1B-2, Ar 3 is benzene, naphthylene, anthracene, thiophene, selenophene, tellurophene, pyridine, pyrimidine, or two or more fused rings selected from among these.

[0049] The n-type semiconductor is, for example, but not limited to, a fullerene or a fullerene derivative.

[0050] The photoelectric conversion layer 30 is an intrinsic layer (I layer) in which a p-type semiconductor and an n-type semiconductor are mixed in a bulk heterojunction configuration. In this case, the p-type semiconductor and the n-type semiconductor are mixed in a volume ratio of about 1:9 to 9:1, for example, about 2:8 to 8:2 within this range, about 3:7 to 7:3 within this range, about 4:6 to 6:4 within this range, or about 5:5 within this range.

[0051] The photoelectric conversion layer 30 includes a double layer including a p-type layer including the above-described p-type semiconductor and an n-type layer including the above-described n-type semiconductor, where the thickness ratio of the p-type layer to the n-type layer is about 1:9 to 9:1, and within this range, for example, about 2:8 to 8:2, about 3:7 to 7:3, about 4:6 to 6:4, or about 5:5.

[0052] The photoelectric conversion layer 30 further includes a p-type layer and / or an n-type layer in addition to the intrinsic layer. The p-type layer includes the p-type semiconductor described above, and the n-type layer includes the n-type semiconductor described above. For example, various combinations such as p-type layer / I layer, I layer / n-type layer, and p-type layer / I layer / n-type layer may be included.

[0053] The organic auxiliary layer 40 is located between the first electrode 10 and the photoelectric conversion layer 30, and is in contact with, for example, the photoelectric conversion layer 30. For example, one surface of the organic auxiliary layer 40 is in contact with the first electrode 10, and the other surface of the organic auxiliary layer 40 is in contact with the photoelectric conversion layer 30.

[0054] The organic auxiliary layer 40 is a layer for effectively improving the extraction of charges (for example, electrons) moving from the photoelectric conversion layer 30 to the first electrode 10, and includes, for example, an organic semiconductor having high charge mobility.

[0055] As an example, the charge mobility of the organic auxiliary layer 40 is higher than the charge mobility of the photoelectric conversion layer 30, for example, the charge mobility of the organic auxiliary layer 40 is about 50 times or more higher than the charge mobility of the photoelectric conversion layer 30, and within such a range, it is about 70 times or more, about 80 times or more, about 100 times or more, about 120 times or more, about 150 times or more, or about 200 times or more higher.

[0056] As an example, the charge mobility of the organic auxiliary layer 40 is, for example, about 1.0×10 -3 cm 2 / Vs or more, and within this range, for example, about 1.2 × 10 -3 cm 2 / Vs or more, approximately 1.5×10 -3 cm 2 / Vs or more, approximately 1.8×10 -3 cm 2 / Vs or more, approximately 2.0×10 -3 cm 2 / Vs or more, approximately 3.0×10 -3 cm 2 / Vs or more, approximately 4.0×10 -3 cm 2 / Vs or more, or approximately 5.0 × 10 -3 cm 2 / Vs or more.

[0057] As an example, the charge mobility of the organic auxiliary layer 40 is, for example, about 1.0×10 -3 cm 2 / Vs~10cm 2 / Vs, and within this range, for example, about 1.2 × 10 -3 cm 2 / Vs~10cm 2 / Vs, approximately 1.5×10 -3 cm 2 / Vs~10cm 2 / Vs, approximately 1.8×10 -3 cm 2 / Vs~10cm 2 / Vs, approx. 2.0×10 -3 cm 2 / Vs~10cm 2 / Vs, approx. 3.0×10 -3 cm 2 / Vs~10cm 2 / Vs, approx. 4.0×10-3 cm 2 / Vs~10cm 2 / Vs, or approximately 5.0 × 10 -3 cm 2 / Vs~10cm 2 / Vs.

[0058] As an example, the photoelectric conversion layer 30 includes a first organic material that is one of the above-mentioned p-type semiconductors or n-type semiconductors, and the organic auxiliary layer 40 includes a second organic material that is different from the first organic material. In this case, the charge mobility of the second organic material is about 50 times or more higher than the charge mobility of the first organic material, and within this range, it is about 70 times or more, about 80 times or more, about 100 times or more, about 120 times or more, about 150 times or more, about 200 times or more, about 300 times or more, about 500 times or more, about 800 times or more, or about 1000 times or more higher.

[0059] For example, the charge mobility of the second organic material is about 1.0×10 -3 cm 2 / Vs or more, and within this range, for example, about 1.2 × 10 -3 cm 2 / Vs or more, approximately 1.5×10 -3 cm 2 / Vs or more, approximately 1.8×10 -3 cm 2 / Vs or more, approximately 2.0×10 -3 cm 2 / Vs or more, approximately 3.0×10 -3 cm 2 / Vs or more, approximately 4.0×10 -3 cm 2 / Vs or more, or approximately 5.0 × 10 -3 cm 2 / Vs or more.

[0060] For example, the charge mobility of the second organic material is about 1.0×10 -3 cm 2 / Vs~10cm 2 / Vs, and within this range, for example, about 1.2 × 10 -3 cm 2 / Vs~10cm 2 / Vs, approximately 1.5×10 -3 cm2 / Vs~10cm 2 / Vs, approximately 1.8×10 -3 cm 2 / Vs~10cm 2 / Vs, approx. 2.0×10 -3 cm 2 / Vs~10cm 2 / Vs, approx. 3.0×10 -3 cm 2 / Vs~10cm 2 / Vs, approx. 4.0×10 -3 cm 2 / Vs~10cm 2 / Vs, or approximately 5.0 × 10 -3 cm 2 / Vs~10cm 2 / Vs.

[0061] Meanwhile, the second organic material is a material that satisfies the above-mentioned charge mobility and is formed by thermal evaporation. Since the organic auxiliary layer 40 is formed by thermal evaporation, the photoelectric conversion layer 30 is prevented from being thermally or physically damaged during the formation of the organic auxiliary layer 40 and / or subsequent processes, thereby preventing performance degradation due to deterioration of the photoelectric conversion layer 30.

[0062] Examples of the second organic material that satisfies these characteristics include a small molecule organic semiconductor, a polymer semiconductor, or a combination thereof, such as a small molecule organic semiconductor. Here, the small molecule organic semiconductor is an organic semiconductor having an average molecular weight of about 3000 or less.

[0063] For example, the second organic material may be an aromatic compound and / or a heteroaromatic compound, such as a fused polycyclic aromatic compound, a fused polycyclic heteroaromatic compound, or a combination thereof, such as a fused polycyclic aromatic compound such as pentacene and / or a fused polycyclic heteroaromatic compound containing at least one of O, S, Se, Te, N, or a combination thereof, such as a fused polycyclic heteroaromatic compound containing at least one of S, Se, Te, or a combination thereof.

[0064] For example, the second organic substance is a fused polycyclic aromatic compound and / or a fused polycyclic heteroaromatic compound having a compact planar structure in which four or more rings are fused to each other, such as a fused polycyclic aromatic compound and / or a fused polycyclic heteroaromatic compound having 5, 6, 7, 8, 9, 10, 11, or 12 fused rings.

[0065] As an example, the second organic substance is a fused polycyclic aromatic compound and / or a fused polycyclic heteroaromatic compound containing at least one benzene ring.

[0066] In one example, the second organic material is a fused polycyclic heteroaromatic compound containing at least one thiophene, selenophene, and / or tellurophene.

[0067] As an example, the second organic material may be represented by the following chemical formula 2A or 2B, but is not limited thereto.

[0068] [ka] [ka]

[0069] In the above chemical formulas 2A and 2B, Ar 1 and Ar2 are each independently substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, or substituted or unsubstituted anthracene; a is Ar 1 and Ar 2 corresponds to the number of hydrogen atoms bonded to the carbon atom, X 1 ~X 4 are each independently O, S, Se, Te, or NR a where R a are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms (-OR b , where R b is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms), a substituted or unsubstituted cycloalkyl group having 4 to 30 carbon atoms, a substituted or unsubstituted cycloalkyloxy group having 4 to 30 carbon atoms (-OR c , where R c is a substituted or unsubstituted cycloalkyl group having 4 to 30 carbon atoms), a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, an acyl group (C(═O)R d , where R d represents a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms), a sulfonyl group (-S(=O)R e , where R e represents a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms), or a carbamate group (-NHC(=O)OR f , where R f is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, R 1 ~R 13each independently represents a hydrogen atom, 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 alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted heteroarylalkyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkylheteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 2 to 30 carbon atoms; n1 is 0 or 1, n2 and n3 are each independently 0, 1, 2, or 3; when n1 is 0, n2 and n3 are 1, 2, or 3; When n1 is 1, n1+n2+n3≧2 is satisfied.

[0070] For example, R 1 and R 7 is a substituted or unsubstituted alkyl 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 2 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted heteroarylalkyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkylheteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 2 to 30 carbon atoms.

[0071] For example, R a is a substituted or unsubstituted alkyl group having 10 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 10 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 10 to 30 carbon atoms, or a substituted or unsubstituted alkynyl group having 10 to 30 carbon atoms, and other examples thereof include a fluoro-substituted alkyl group having 1 to 30 carbon atoms, preferably a perfluoroalkyl group having 1 to 30 carbon atoms (C n F 2n+1, where n is an integer of 1 or more), or a fluoro-substituted alkyl group having 10 to 30 carbon atoms, preferably a perfluoroalkyl group having 10 to 30 carbon atoms (C n F 2n+1 , where n is an integer from 10 to 30).

[0072] In the above chemical formulas 2A and 2B, when n1 is 0, n2 and n3 are integers of 1, 2, or 3, and when n1 is 1, n1 + n2 + n3 ≥ 2 is satisfied. For example, when n1 is 1, n2 and n3 are not all 0.

[0073] The second organic substance may be, for example, one of the compounds listed in Group 1 below, but is not limited thereto.

[0074] [Group 1]

[0075] [ka] [ka] [ka] [ka] [ka]

[0076] In the compounds of Group 1, hydrogen atoms of each of the benzene, thiophene, selenophene, and / or pyrrole groups are substituted with 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 alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted heteroarylalkyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkylheteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 2 to 30 carbon atoms.

[0077] As an example, the second organic material may be represented by the following chemical formula 3A or 3B, but is not limited thereto.

[0078] [ka]

[0079] In the above chemical formulas 3A and 3B, X 1 and X 2 are each independently O, S, Se, Te, or NR a where R a represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted arylalkyl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted acyl group having 1 to 30 carbon atoms, a sulfonyl group, or a carbamate group; R 1 ~R 4are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 1 to 30 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroarylalkyl group having 2 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms.

[0080] The organic semiconductor material represented by the above chemical formula 3A is represented, for example, by the following chemical formula 3A-1, and the organic semiconductor material represented by the above chemical formula 3B is represented, for example, by the following chemical formula 3B-1.

[0081] [ka]

[0082] In the above chemical formulas 3A-1 and 3B-1, R 1 ~R 4 is as described above.

[0083] By way of example, the second organic substance may be, but is not limited to, one of the compounds listed in Group 2 below.

[0084] [Group 2]

[0085] [ka]

[0086] In the compounds of Group 2, hydrogen atoms of each benzene and / or thiophene are substituted with 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 alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted heteroarylalkyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkylheteroaryl group having 2 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted heterocycloalkyl group having 2 to 30 carbon atoms.

[0087] For example, the organic auxiliary layer 40 may further include an organic material, an inorganic material, and / or an organic-inorganic material in addition to the second organic material.

[0088] For example, the organic auxiliary layer 40 further includes the p-type semiconductor and / or the n-type semiconductor included in the photoelectric conversion layer 30 .

[0089] As an example, the organic auxiliary layer 40 further includes a p-type semiconductor contained in the photoelectric conversion layer 30. For example, the second organic material and the p-type semiconductor are mixed at a volume ratio of about 1:9 to 9:1, and within this range, for example, about 2:8 to 8:2, for example, about 3:7 to 7:3, for example, about 4:6 to 6:4, for example, about 5:5.

[0090] As an example, the organic auxiliary layer 40 further includes an n-type semiconductor contained in the photoelectric conversion layer 30. For example, the second organic material and the n-type semiconductor are mixed at a volume ratio of about 1:9 to 9:1, and within this range, for example, about 2:8 to 8:2, for example, about 3:7 to 7:3, for example, about 4:6 to 6:4, for example, about 5:5.

[0091] As an example, the organic auxiliary layer 40 further includes a p-type semiconductor and an n-type semiconductor included in the photoelectric conversion layer 30. For example, the second organic material and the p-type semiconductor / n-type semiconductor are mixed at a volume ratio of about 1:9 to 9:1, and within this range, for example, about 2:8 to 8:2, for example, about 3:7 to 7:3, for example, about 4:6 to 6:4, for example, about 5:5.

[0092] As an example, the organic auxiliary layer 40 further includes a fullerene or a fullerene derivative. For example, the second organic material and the fullerene or fullerene derivative are mixed in a volume ratio of about 1:9 to 9:1, and within this range, for example, about 2:8 to 8:2, for example, about 3:7 to 7:3, for example, about 4:6 to 6:4, or for example, about 5:5.

[0093] The organic auxiliary layer 40 is thinner than the photoelectric conversion layer 30, and has a thickness of, for example, about 10 nm or less, within such a range, about 5 nm or less. For example, the organic auxiliary layer 40 has a thickness of about 1 nm to 10 nm, within such a range, about 1 nm to 5 nm.

[0094] As described above, the photoelectric conversion element 100 includes the organic auxiliary layer 40 between the first electrode 10 and the photoelectric conversion layer 30, thereby effectively increasing the extraction of charges (e.g., electrons) moving from the photoelectric conversion layer 30 to the first electrode 10 and reducing remaining charge carriers, thereby exhibiting high charge extraction efficiency. As a result, the photoelectric conversion efficiency of the photoelectric conversion element 100 can be increased, and image lag caused by remaining charges can be reduced, thereby effectively improving image retention characteristics.

[0095] The photoelectric conversion element 100 may further include an anti-reflection layer (not shown) on one side of the first electrode 10 or the second electrode 20. The anti-reflection layer is disposed on the light incident side to reduce the reflectivity of the incident light, thereby further improving light absorbance. For example, when light is incident on the first electrode 10 side, the anti-reflection layer is disposed on one side of the first electrode 10, and when light is incident on the second electrode 20 side, the anti-reflection layer is disposed on one side of the second electrode 20.

[0096] The anti-reflection layer may include a material having a refractive index of, for example, about 1.6 to 2.5, such as at least one of a metal oxide, a metal sulfide, and an organic material having a refractive index in this 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.

[0097] When light is incident on the first electrode 10 or the second electrode 20 side of the photoelectric conversion element 100 and the photoelectric conversion layer 30 absorbs light in a predetermined wavelength range, excitons are generated inside the element 100. The excitons are separated into holes and electrons in the photoelectric conversion layer 30, and the separated holes move to the anode side, which is one of the first electrode 10 and the second electrode 20, while the separated electrons move to the cathode side, which is the other of the first electrode 10 and the second electrode 20, causing a current to flow.

[0098] The photoelectric conversion element according to the second embodiment will be described below.

[0099] FIG. 2 is a cross-sectional view showing an example of a photoelectric conversion element according to a second embodiment of the present invention.

[0100] Referring to FIG. 2, a photoelectric conversion element 200 according to this embodiment includes a first electrode 10, a second electrode 20, a photoelectric conversion layer 30, and an organic auxiliary layer 40, similar to the above-described embodiments.

[0101] However, unlike the above-described embodiments, the photoelectric conversion element 200 according to this embodiment further includes a charge blocking layer 48 between the second electrode 20 and the photoelectric conversion layer 30. The charge blocking layer 48 can block charges (e.g., electrons) separated from the photoelectric conversion layer 30 from moving toward the opposite electrode, thereby increasing photoelectric conversion efficiency.

[0102] The charge blocking layer 48 can be, for example, organic, inorganic, or organic-inorganic. The organic material is an organic compound that has hole or electron properties, and the inorganic material is a metal oxide such as molybdenum oxide, tungsten oxide, or nickel oxide.

[0103] The charge blocking layer 48 includes, for example, a visible light non-absorbing material that does not substantially absorb light in the visible light region, such as a visible light non-absorbing organic material.

[0104] As an example, the visible light non-absorbing substance is a compound represented by the following chemical formula 4A or 4B, but is not limited thereto.

[0105] [ka] [ka]

[0106] In the above chemical formula 4A or 4B, M 1 and M 2 are each independently n R o , SiR p R q , N.R. r , O, S, Se, or Te; Ar 1b , Ar 2b , Ar 3b , and Ar4b are each 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 are each independently a single bond, -(CR s R t ) n3 -, -O-, -S-, -Se-, -N=, -NR u -, -SiR v R w - or -GeR x R y where n3 is 1 or 2; R 30 ~R 37 and R n ~R y are each independently a hydrogen atom, a substituted or unsubstituted alkyl 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, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a cyano group.

[0107] As an example, the visible light non-absorbing substance is a compound represented by the following chemical formula 4A-1 or 4B-1, but is not limited thereto.

[0108] [ka] [ka]

[0109] In the above chemical formula 4A-1 or 4B-1, M 1 , M 2 , G 2 , G 3 , R 30 ~R 37 is as described above, R 38 ~R 45are each independently a hydrogen atom, a substituted or unsubstituted alkyl 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 substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, a halogen atom, or a cyano group.

[0110] As an example, the visible light non-absorbing substance is a compound represented by the following chemical formula 4A-1a or 4B-1a, but is not limited thereto.

[0111] [ka] [ka]

[0112] In the above chemical formula 4A-1a or 4B-1a, R 38 ~R 45 , and R o and R n is as described above.

[0113] The photoelectric conversion element 200 according to this embodiment further includes a charge blocking layer 48 between the second electrode 20 and the photoelectric conversion layer 30 in addition to the organic auxiliary layer 40 located between the first electrode 10 and the photoelectric conversion layer 30, thereby allowing holes and electrons separated from the photoelectric conversion layer 30 to efficiently move to the anode and cathode sides, respectively, thereby further improving the charge extraction efficiency.

[0114] The photoelectric conversion element according to the third embodiment will be described below.

[0115] FIG. 3 is a cross-sectional view showing an example of a photoelectric conversion element according to a third embodiment of the present invention.

[0116] Referring to FIG. 3, a photoelectric conversion element 300 according to this embodiment includes a first electrode 10, a second electrode 20, a photoelectric conversion layer 30, and an organic auxiliary layer 40, similar to the above-described embodiments.

[0117] However, unlike the above-described embodiments, the photoelectric conversion element 300 according to this embodiment further includes an inorganic nanolayer 45 .

[0118] The inorganic nanolayer 45 is located between the first electrode 10 and the photoelectric conversion layer 30, for example, in contact with the first electrode 10. As an example, the organic auxiliary layer 40 is in contact with the photoelectric conversion layer 30, and the inorganic nanolayer 45 is in contact with the first electrode 10, and as an example, the organic auxiliary layer 40 and the inorganic nanolayer 45 are in contact with each other.

[0119] The inorganic nanolayer 45 is a very thin film having a thickness of a few nanometers, for example, about 5 nm or less, for example, about 3 nm or less, for example, about 2 nm or less, for example, about 1 nm to 5 nm, about 1 nm to 3 nm, or about 1 nm to 2 nm.

[0120] The inorganic nanolayer 45 includes an inorganic material having a lower work function than the first electrode 10. For example, the work function of the inorganic nanolayer 45 is at least about 0.5 eV lower than the work function of the first electrode 10. For example, the work function of the first electrode 10 is at least about 4.5 eV, and the work function of the inorganic nanolayer 45 is at most about 4.0 eV. For example, the work function of the first electrode 10 is at least about 4.5 eV, and the work function of the inorganic nanolayer 45 is at most about 3.5 eV. For example, the work function of the first electrode 10 is at least about 4.5 eV, and the work function of the inorganic nanolayer 45 is at most about 3.0 eV. For example, the work function of the first electrode 10 is at least about 4.5 eV, and the work function of the inorganic nanolayer 45 is at most about 2.8 eV. For example, the work function of the first electrode 10 is about 4.5 eV to 5.0 eV, and the work function of the inorganic nanolayer 45 is about 1.5 eV to 4.0 eV, about 1.5 eV to 3.5 eV, about 1.5 eV to 3.0 eV, or about 1.5 eV to 2.8 eV.

[0121] The inorganic nanolayer 45 includes, for example, a lanthanum group element, calcium (Ca), potassium (K), aluminum (Al), or an alloy thereof. The lanthanum group element includes, for example, ytterbium (Yb).

[0122] As described above, the inorganic nanolayer 45 is in contact with the surface of the first electrode 10 between the first electrode 10 and the photoelectric conversion layer 30, and has a thickness that is much thinner than that of the first electrode 10. As a result, the inorganic nanolayer 45 functions on the surface of the first electrode 10 in the same manner as a surface treatment layer of the first electrode 10.

[0123] As an example, the effective work function at the surface of the first electrode 10 is different from the work function of the transparent conductor or reflective conductor that forms the first electrode 10 due to the influence of the inorganic nanolayer 45, and for example, the effective work function at the surface of the first electrode 10 is smaller than the work function of the transparent conductor or reflective conductor that forms the first electrode 10. For example, the effective work function at the surface of the first electrode 10 is the same as the work function of the inorganic nanolayer 45 or is an intermediate value between the work function of the inorganic nanolayer 45 and the work function of the first electrode 10.

[0124] As an example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 is about 4.5 eV or more, and the effective work function at the surface of the first electrode 10 is about 4.0 eV or less. For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 is about 4.5 eV or more, and the effective work function at the surface of the first electrode 10 is about 3.5 eV or less. For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 is about 4.5 eV or more, and the effective work function at the surface of the first electrode 10 is about 3.0 eV or less. For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 is about 4.5 eV or more, and the effective work function at the surface of the first electrode 10 is about 2.8 eV or less. For example, the work function of the transparent conductor or reflective conductor forming the first electrode 10 is approximately 4.5 eV to 5.0 eV, and the effective work function at the surface of the first electrode 10 is approximately 1.5 eV to 4.0 eV, approximately 1.5 eV to 3.5 eV, approximately 1.5 eV to 3.0 eV, or approximately 1.5 eV to 2.8 eV.

[0125] In this way, by lowering the work function at the surface of the first electrode 10, it becomes easier to extract charges (e.g., electrons) that move from the photoelectric conversion layer 30 through the organic auxiliary layer 40 to the first electrode 10, further reducing residual charges and exhibiting higher charge extraction efficiency.

[0126] The photoelectric conversion element according to the fourth embodiment will be described below.

[0127] FIG. 4 is a cross-sectional view showing an example of a photoelectric conversion element according to a fourth embodiment of the present invention.

[0128] Referring to FIG. 4, a photoelectric conversion element 400 according to this embodiment includes a first electrode 10, a second electrode 20, a photoelectric conversion layer 30, an organic auxiliary layer 40, and an inorganic nanolayer 45, similar to the above-described embodiments.

[0129] However, unlike the above-described embodiments, the photoelectric conversion element 400 according to this embodiment further includes a charge blocking layer 48 between the second electrode 20 and the photoelectric conversion layer 30. The charge blocking layer 48 can block charges (e.g., holes) separated from the photoelectric conversion layer 30 from moving toward the opposite electrode, thereby improving photoelectric conversion efficiency, as described above in detail.

[0130] The above-described photoelectric conversion devices (100, 200, 300, 400) can be applied to various electronic devices, such as, but not limited to, solar cells, organic sensors, photodetectors, and optical sensors.

[0131] The photoelectric conversion elements (100, 200, 300, 400) are applied to, for example, organic sensors.

[0132] An example of an organic sensor to which the above-described photoelectric conversion elements (100, 200, 300, 400) are applied will be described below with reference to the drawings.

[0133] FIG. 5 is a cross-sectional view schematically illustrating an example of an organic sensor according to one embodiment of the present invention.

[0134] In one example, the organic sensor is an organic CMOS image sensor.

[0135] Referring to FIG. 5, an organic sensor 500 according to this embodiment includes a semiconductor substrate 110, an insulating layer 80, a photoelectric conversion element 100, and a color filter layer .

[0136] The semiconductor substrate 110 may be a silicon substrate, on which a transfer transistor (not shown) and a charge reservoir 55 are integrated. A transfer transistor and / or a charge reservoir 55 are integrated for each pixel.

[0137] Metal wiring (not shown) and pads (not shown) are further formed on the semiconductor substrate 110. The metal wiring and pads are made of a metal having low resistivity to reduce signal delay, such as, but not limited to, aluminum (Al), copper (Cu), silver (Ag), and alloys thereof.

[0138] 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 dielectric constant (low K) material such as SiC, SiCOH, SiCO, and SiOF. The insulating layer 80 has a trench 85 exposing the charge reservoir 55. The trench 85 is filled with a filling material.

[0139] The above-described photoelectric conversion element 100 is formed on the insulating layer 80. As described above, the photoelectric conversion element 100 includes the first electrode 10, the organic auxiliary layer 40, the photoelectric conversion layer 30, and the second electrode 20. The specific description is as described above.

[0140] 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. 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 of or in addition to the blue filter, a red filter 70b formed in the red pixel, and a green filter 70c formed in the green pixel.

[0141] An insulating film (not shown) is further formed between the photoelectric conversion element 100 and the color filter layer 70.

[0142] Condenser lenses (not shown) are further formed on the color filter layer 70. The condenser lenses control the direction of incident light and focus the light at one point. The condenser lenses may be, for example, cylindrical or hemispherical, but are not limited thereto.

[0143] 5 shows an example of a structure in which the photoelectric conversion elements 100 of FIG. 1 are stacked, but a structure in which the photoelectric conversion elements (200, 300, 400) of FIG. 2, FIG. 3, or FIG. 4 are stacked can also be applied in the same way.

[0144] FIG. 6 is a cross-sectional view schematically illustrating another example of an organic sensor according to an embodiment of the present invention.

[0145] Referring to FIG. 6, the image sensor 600 according to this embodiment includes a semiconductor substrate 110 on which a transfer transistor (not shown) and a charge storage 55 are integrated, an insulating layer 80, a photoelectric conversion element 100, and a color filter layer 70, similar to the above-described embodiments.

[0146] However, the image sensor 600 according to this embodiment differs from the above-described embodiments in that the positions of the first electrode 10 and the second electrode 20 of the photoelectric conversion element 100 are interchanged. That is, the first electrode 10 is a light-receiving electrode.

[0147] 6 shows an example of a structure in which the photoelectric conversion elements 100 of FIG. 1 are stacked, but a structure in which the photoelectric conversion elements (200, 300, 400) of FIG. 2, FIG. 3, or FIG. 4 are stacked can also be applied in the same way.

[0148] FIG. 7 is a plan view schematically showing an example of an organic sensor according to one embodiment of the present invention, and FIGS. 8 and 9 are cross-sectional views schematically showing the example and another example of the organic sensor of FIG. 7, respectively.

[0149] 7 and 8, the organic sensor 700 according to this embodiment includes a semiconductor substrate 110 on which photo-sensing elements (50a, 50b), a transfer transistor (not shown), and a charge reservoir 55 are integrated, a lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a photoelectric conversion element 100.

[0150] The semiconductor substrate 110 may be a silicon substrate, and integrates the photo-sensing elements (50a, 50b), a transfer transistor (not shown), and a charge reservoir 55. The photo-sensing elements (50a, 50b) may be photodiodes.

[0151] A photo-sensing element (50a, 50b), a transfer transistor, and / or a charge reservoir 55 are integrated for each pixel, and as an example, as can be seen from the figure, a photo-sensing element (50a, 50b) is included in each blue pixel and red pixel, and a charge reservoir 55 is included in each green pixel.

[0152] The photo-sensing elements (50a, 50b) sense light, and the sensed information is transmitted by a transmission transistor. The charge reservoir 55 is electrically connected to the photoelectric conversion element 100 described later, and the information in the charge reservoir 55 is transmitted by a transmission transistor.

[0153] Metal wiring (not shown) and pads (not shown) are further formed on the semiconductor substrate 110. The metal wiring and pads are made of a metal having low resistivity to reduce signal delay, such as, but not limited to, aluminum (Al), copper (Cu), silver (Ag), and alloys thereof. However, without being limited to the above structure, the metal wiring and pads may be located below the photo-sensing elements 50a and 50b.

[0154] A lower insulating layer 60 is formed over 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 a trench 85 exposing the charge reservoir 55. The trench 85 is filled with a filling material.

[0155] A color filter layer 70 is formed on the lower insulating layer 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. In this embodiment, an example in which a green filter is not provided will be described, but a green filter may be provided in some cases. As another example, the color filter layer 70 may be located on top of the photoelectric conversion element 100.

[0156] 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 55 of green pixels.

[0157] The above-described photoelectric conversion element 100 is formed on the upper insulating layer 80. As described above, the photoelectric conversion element 100 includes the first electrode 10, the organic auxiliary layer 40, the photoelectric conversion layer 30, and the second electrode 20. The specific description is as described above.

[0158] A condenser lens (not shown) is further formed on the photoelectric conversion element 100. The condenser lens controls the direction of incident light and focuses the light at one point. The condenser lens may have, for example, a cylindrical or hemispherical shape, but is not limited thereto.

[0159] Referring to FIG. 9, the image sensor 800 according to this embodiment includes a semiconductor substrate 110 on which photo-sensing elements (50a, 50b), transfer transistors (not shown), and charge reservoirs 55 are integrated, a lower insulating layer 60, a color filter layer 70, an upper insulating layer 80, and a photoelectric conversion element 100, similar to the above-described embodiments.

[0160] However, the image sensor 800 according to this embodiment differs from the above-described embodiment in that the positions of the first electrode 10 and the second electrode 20 are interchanged. That is, the first electrode 10 is a light-receiving electrode.

[0161] 8 and 9 show an example of a structure in which the photoelectric conversion elements 100 of FIG. 1 are stacked, but a structure in which the photoelectric conversion elements (200, 300, 400) of FIG. 2, FIG. 3, or FIG. 4 are stacked can also be applied in the same way.

[0162] FIG. 10 is a cross-sectional view schematically illustrating an example of an organic sensor according to another embodiment of the present invention.

[0163] The image sensor 900 according to this embodiment includes a semiconductor substrate 110 in which photo-sensing elements (50a, 50b), transfer transistors (not shown), and charge reservoirs 55 are integrated, an insulating layer 80 having trenches 85, and a photoelectric conversion element 100, similar to the above-described embodiments.

[0164] However, unlike the above-described embodiments, the image sensor 900 according to this embodiment has photo-sensing elements 50a and 50b stacked vertically and omits the color filter layer 70. The photo-sensing elements 50a and 50b are electrically connected to a charge reservoir (not shown) and transmitted by a transfer transistor. The photo-sensing elements 50a and 50b selectively absorb light in each wavelength range depending on the stacking depth.

[0165] Although FIG. 10 shows an example of a structure in which the photoelectric conversion elements 100 of FIG. 1 are stacked, a structure in which the photoelectric conversion elements (200, 300, 400) of FIG. 2, FIG. 3, or FIG. 4 are stacked can also be applied in the same way.

[0166] FIG. 11 is a cross-sectional view schematically illustrating another example of an organic sensor according to another embodiment of the present invention.

[0167] 11, the image sensor 1000 according to this embodiment includes, similarly to the above-described embodiment, a semiconductor substrate 110 in which photo-sensing elements (50a, 50b), transfer transistors (not shown), and charge reservoirs 55 are integrated, an insulating layer 80 having trenches 85, and a photoelectric conversion element 100. However, unlike the above-described embodiment, the image sensor 1000 according to this embodiment has the positions of the first electrode 10 and the second electrode 20 interchanged. That is, the first electrode 10 is a light-receiving electrode.

[0168] Although FIG. 11 shows an example of a structure in which the photoelectric conversion elements 100 of FIG. 1 are stacked, a structure in which the photoelectric conversion elements (200, 300, 400) of FIG. 2, FIG. 3, or FIG. 4 are stacked can also be applied in the same way.

[0169] FIG. 12 is a plan view schematically illustrating an example of an organic sensor according to another embodiment of the present invention, and FIG. 13 is a cross-sectional view illustrating the example of the organic sensor of FIG.

[0170] The organic sensor 1100 according to this embodiment has a stacked structure of a green photoelectric conversion element that selectively absorbs light in the green wavelength region, a blue photoelectric conversion element that selectively absorbs light in the blue wavelength region, and a red photoelectric conversion element that selectively absorbs light in the red wavelength region.

[0171] The organic sensor 1100 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.

[0172] The semiconductor substrate 110 may be a silicon substrate, and includes transfer transistors (not shown) and charge reservoirs (55a, 55b, 55c) integrated thereon. 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.

[0173] On the lower insulating layer 60, the first photoelectric conversion element 100a is formed.

[0174] The first photoelectric conversion element 100a includes a first electrode 10a and a second electrode 20a facing each other, and a photoelectric conversion layer 30a and an organic auxiliary layer 40a located between the first electrode 10a and the second electrode 20a. The first electrode 10a, the second electrode 20a, the photoelectric conversion layer 30a, and the organic auxiliary layer 40a are as described above, and the photoelectric conversion layer 30a selectively absorbs light in one of the wavelength regions of red, blue, and green. For example, the first photoelectric conversion element 100a is a red photoelectric conversion element.

[0175] An intermediate insulating layer 65 is formed on the first photoelectric conversion element 100a.

[0176] On the intermediate insulating layer 65, the second photoelectric conversion element 100b is formed.

[0177] The second photoelectric conversion element 100b includes a first electrode 10b and a second electrode 20b facing each other, and a photoelectric conversion layer 30b and an organic auxiliary layer 40b located between the first electrode 10b and the second electrode 20b. The first electrode 10b, the second electrode 20b, the photoelectric conversion layer 30b, and the organic auxiliary layer 40b are as described above, and the photoelectric conversion layer 30b selectively absorbs light in any one of the wavelength regions of red, blue, and green. For example, the second photoelectric conversion element 100b is a blue photoelectric conversion element.

[0178] 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 85 exposing the charge reservoirs (55a, 55b, 55c).

[0179] A third photoelectric conversion element 100c is formed on the upper insulating layer 80. The third photoelectric conversion element 100c includes a first electrode 10c and a second electrode 20c facing each other, and a photoelectric conversion layer 30c and an organic auxiliary layer 40c located between the first electrode 10c and the second electrode 20c. The first electrode 10c, the second electrode 20c, the photoelectric conversion layer 30c, and the organic auxiliary layer 40c are as described above, and the photoelectric conversion layer 30c selectively absorbs light in any one of the wavelength regions of red, blue, and green. For example, the third photoelectric conversion element 100c is a green photoelectric conversion element, and the above-described photoelectric conversion element 100 is applied.

[0180] A condenser lens (not shown) is further formed on the photoelectric conversion element 100c. The condenser lens controls the direction of incident light and focuses the light at one point. The condenser lens may be, for example, cylindrical or hemispherical, but is not limited thereto.

[0181] In the drawings, the photoelectric conversion element 100 of Figure 1 is shown as an example of the first photoelectric conversion element 100a, the second photoelectric conversion element 100b, and the third photoelectric conversion element 100c, but the photoelectric conversion elements (200, 300, 400) shown in Figure 2, Figure 3, or Figure 4 can also be applied in the same way.

[0182] 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 variously changed.

[0183] 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 absorbing light in a different wavelength range, the size of the image sensor can be further reduced, thereby realizing a miniaturized image sensor.

[0184] FIG. 14 is a cross-sectional view schematically showing another example of the organic sensor of FIG.

[0185] 14, an image sensor 1200 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, similar to the above-described embodiment. However, unlike the above-described embodiment, the positions of the first electrode 10 and the second electrode 20 of the first photoelectric conversion element 100a, the second photoelectric conversion element 100b, and the third photoelectric conversion element 100c are interchanged. In other words, the first electrode 10 is a light-receiving electrode.

[0186] FIG. 15 is a plan view schematically illustrating an organic CMOS image sensor according to an embodiment of the present invention, and FIG. 16 is a cross-sectional view illustrating an example of the organic CMOS image sensor of FIG.

[0187] 15 and 16, the organic CMOS image sensor 1300 includes a photoelectric conversion element 90 disposed on a semiconductor substrate 110, the photoelectric conversion element 90 including a plurality of photoelectric conversion elements 90-1, 90-2, and 90-3. The photoelectric conversion elements 90-1, 90-2, and 90-3 convert light of different wavelength regions (e.g., blue light, green light, or red light) into electrical signals. Referring to FIG. 16, the photoelectric conversion elements 90-1, 90-2, and 90-3 are arranged side by side in the horizontal direction on the semiconductor substrate 110 and partially or entirely overlap each other in a direction extending side by side across the surface 110a of the semiconductor substrate 110. Each of the photoelectric conversion elements 90-1, 90-2, and 90-3 is connected to a charge reservoir 55 integrated within the semiconductor substrate 110 through a trench 85.

[0188] Each of the photoelectric conversion elements (90-1, 90-2, 90-3) is one of the photoelectric conversion elements (100, 200) described above. For 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). For 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. For example, the two or more photoelectric conversion elements (90-2, 90-2, 90-3) have different photoelectric conversion layers 30 that absorb light in different wavelength ranges of incident light. For example, the two or more photoelectric conversion elements (90-1, 90-2, 90-3) include inorganic nanolayers 40 with different configurations. Other structures of the organic CMOS image sensor 1300 are similar to one or more of the organic CMOS images described with reference to FIGS.

[0189] FIG. 17 is a cross-sectional view showing another example of an organic CMOS image sensor.

[0190] 17, an organic CMOS image sensor 1400 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 each other in a direction extending side by side on a 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 electrical signals.

[0191] For example, the photoelectric conversion element 90-1 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 entirely or partially overlaps the photoelectric conversion element 90-1. Other structures of the organic CMOS image sensor 1400 are similar to one or more of the organic CMOS images described with reference to FIGS. 5 to 14.

[0192] FIG. 18 is a cross-sectional view showing yet another example of an organic CMOS image sensor.

[0193] Referring to FIG. 18, the organic CMOS image sensor 1500 includes a semiconductor substrate 110 on which photo-sensing elements (50a, 50b), transfer transistors (not shown), and charge reservoirs 55 are integrated, a lower insulating layer 60 and a color filter layer 70 located on the semiconductor substrate 110, and an upper insulating layer 80 and a photoelectric conversion element 90 located on the semiconductor substrate 110. The photoelectric conversion element 90 may be the photoelectric conversion element 100, 200 described above. In FIG. 18, since the photoelectric conversion element 90 is located on the lower side of the semiconductor substrate 110, the photoelectric conversion element 90 and the color filter layer 70 are located separately from the photo-sensing elements (50a, 50b). Other structures of the organic CMOS image sensor 1500 are similar to one or more of the organic CMOS image sensors described with reference to FIGS. 5 to 14.

[0194] The organic sensors including the photoelectric conversion elements and image sensors described above are applied to various electronic devices, such as, but not limited to, mobile phones and digital cameras.

[0195] FIG. 19 is a schematic block diagram of an electronic device according to one embodiment of the present invention.

[0196] 19, an electronic device 1700 includes a processor 1720, a memory 1730, and an organic CMOS image sensor 1740, all electrically connected via a bus 1710. The organic CMOS image sensor 1740 may 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 processor 1720 executes the stored instruction program to perform one or more functions. For example, the processor 1720 processes electrical signals generated by the organic CMOS image sensor 1740. The processor 1720 generates an output (e.g., an image displayed on a display interface) based on such processing.

[0197] The above-described embodiments of the present invention will be described in more detail with reference to the following examples, which are provided for illustrative purposes only and are not intended to limit the scope of the present invention.

[0198] Example 1

[0199] ITO is deposited on a glass substrate by sputtering to form an anode with a thickness of 150 nm. Next, a compound represented by the following chemical formula A is vapor-deposited on the anode to form a charge blocking layer with a thickness of 5 nm. Next, a p-type semiconductor (λ) represented by the following chemical formula B-1 is deposited on the charge blocking layer. max :545nm, charge mobility: 1.5×10 -5 cm 2 / Vs) and fullerene (C60), an n-type semiconductor, were co-evaporated at a volume ratio of 1:1 to form a 90-nm-thick photoelectric conversion layer (charge mobility: 4 × 10 -5 cm2 Next, an organic semiconductor (charge mobility: 1.8 × 10 / Vs) represented by the following chemical formula C-1 is formed on the photoelectric conversion layer. -2 cm 2 A 5 nm thick organic auxiliary layer is formed by thermal evaporation of ITO (WF: 4.7 eV) on the organic auxiliary layer. A 7 nm thick cathode is then formed by sputtering ITO (WF: 4.7 eV). Next, a 50 nm thick anti-reflection layer is formed by evaporation of aluminum oxide (Al2O3) on the cathode, and the resulting structure is sealed with a glass plate to complete the photoelectric conversion element.

[0200] [ka] [ka]

[0201] The charge mobility of the p-type semiconductor represented by the chemical formula B-1 and the organic semiconductor represented by the chemical formula C-1 is measured by a time-of-flight method. Specifically, the time-of-flight method involves forming a semiconductor layer of the p-type semiconductor represented by the chemical formula B-1 or the organic semiconductor represented by the chemical formula C-1 with a thickness of 1 μm between an ITO electrode and an Al electrode (80 nm), and evaluating the photocurrent to confirm the charge mobility.

[0202] <Example 2>

[0203] A photoelectric conversion element was fabricated in the same manner as in Example 1, except that an inorganic nanolayer having a thickness of 1.5 nm was further formed on the organic auxiliary layer by thermal evaporation of Yb (WF: 2.6 eV).

[0204] <Comparative Example 1>

[0205] A photoelectric conversion element is produced in the same manner as in Example 1, except that the organic auxiliary layer is not formed.

[0206] <Reference example 1>

[0207] A photoelectric conversion element is produced in the same manner as in Example 1, except that no organic auxiliary layer is formed and a photoelectric conversion layer with a thickness of 100 nm is formed instead of the photoelectric conversion layer with a thickness of 90 nm.

[0208] <Rating I>

[0209] The photoelectric conversion efficiency according to wavelength of the photoelectric conversion elements according to the example, comparative example, and reference example will be evaluated.

[0210] The photoelectric conversion efficiency is determined by the maximum absorption wavelength (λ max ) (approximately 540 nm), and is evaluated by the incident photon to current efficiency (IPCE) method in the wavelength range of 400 nm to 720 nm.

[0211] The results are shown in Table 1.

[0212] [Table 1]

[0213] Referring to Table 1, it can be seen that the photoelectric conversion elements according to Examples 1 and 2 have improved photoelectric conversion efficiency compared to the photoelectric conversion element according to Comparative Example 1.

[0214] Furthermore, it was confirmed that the photoelectric conversion elements according to Examples 1 and 2 exhibited photoelectric conversion efficiency at a level equivalent to that of the photoelectric conversion element according to Reference Example 1, which includes a thick photoelectric conversion layer. This confirms that the photoelectric conversion elements according to Examples 1 and 2 exhibit high photoelectric conversion efficiency even while reducing the thickness of the photoelectric conversion layer.

[0215] <Evaluation II>

[0216] The photoelectric conversion efficiency according to the applied voltage of the photoelectric conversion elements according to Examples 1 and 2 and Comparative Example 1 will be evaluated.

[0217] The results are shown in Table 2.

[0218] [Table 2]

[0219] Referring to Table 2, it can be seen that the photoelectric conversion elements according to Examples 1 and 2 have improved photoelectric conversion efficiency at each applied voltage compared to the photoelectric conversion element according to Comparative Example 1.

[0220] <Evaluation III>

[0221] The image lag characteristics of the photoelectric conversion elements according to Examples 1 and 2 and Comparative Example 1 are evaluated.

[0222] Image lag can be evaluated by irradiating the photoelectric conversion elements according to the examples and comparative examples with light in a wavelength range where photoelectric conversion occurs for a certain period of time, turning off the light, and measuring the time it takes for the light to reach 6 pA using a Keithley 2400 device. The larger the image lag, the more residual electrons remain, which causes more afterimages.

[0223] The results are shown in Table 3.

[0224] [Table 3]

[0225] Referring to Table 3, it can be seen that the photoelectric conversion elements according to Examples 1 and 2 have reduced image lag compared to the photoelectric conversion element according to Comparative Example 1, thereby confirming that the charge extraction characteristics have been improved.

[0226] <Rating IV>

[0227] Image sensors using the photoelectric conversion elements according to Examples 1 and 2 and Comparative Example 1 are designed, and the YSNR10 of the image sensors is evaluated.

[0228] The YSNR10 of an image sensor is the minimum light level (unit: lux) at which the signal-to-noise ratio (signal / noise) is 10. Here, signal is the sensitivity of the signal obtained through the color correction process in which the RGB raw signal calculated using the finite difference time domain method (FDTD) is passed through a color correction matrix (CCM), and noise is the noise generated when the signal is measured by the image sensor. The color correction process is the process of reducing the difference between the RGB raw signal obtained from the image sensor and the actual color through image processing. The smaller the YSNR10 value, the better the image characteristics in low light levels.

[0229] The results are shown in Table 4.

[0230] [Table 4]

[0231] Referring to Table 4, it can be seen that the photoelectric conversion element according to the embodiment has a lower YSNR10 compared to the photoelectric conversion element according to the comparative example, which is expected to improve the sensitivity of the image sensor.

[0232] 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 concept of the present invention. [Explanation of symbols]

[0233] 10, 10a, 10b, 10c 1st electrode 20, 20a, 20b, 20c 2nd electrode 30, 30a, 30b, 30c Photoelectric conversion layer 40, 40a, 40b, 40c organic auxiliary layer 45, 45a, 45b, 45c Inorganic nanolayers 48 Charge Blocking Layer 50a, 50b, 50c Light-sensing elements 55, 55a, 55b, 55c charge reservoirs 60 Lower insulating layer 65 Intermediate insulating layer 70 color filter layers 70a, 70b, 70c Blue, red, green filters 80 Upper insulating layer, insulating layer 85 Trench 90, 90-1, 90-2, 90-3, 91, 100, 200, 300, 400 Photoelectric conversion element 100a, 100b, 100c First to third photoelectric conversion elements 110 Semiconductor substrate 110a: Surface of semiconductor substrate 500, 600, 700, 800, 900, 1000, 1100, 1200 Image sensor (organic sensor) 1300, 1400, 1500, 1740 organic CMOS image sensor 1700 Electronic equipment 1710 Bus 1720 processor 1730 memory

Claims

1. a first electrode and a second electrode facing each other; a photoelectric conversion layer located between the first electrode and the second electrode, absorbing light in at least a part of a wavelength range and converting the light into an electrical signal; an organic auxiliary layer located between the first electrode and the photoelectric conversion layer and having a charge mobility higher than that of the photoelectric conversion layer; the photoelectric conversion layer contains a first organic material, the organic auxiliary layer includes a second organic material different from the first organic material; the second organic substance is a condensed polycyclic aromatic compound, a condensed polycyclic heteroaromatic compound, or a combination thereof; The condensed polycyclic aromatic compound or the condensed polycyclic heteroaromatic compound has four or more condensed rings, A photoelectric conversion element further comprising an inorganic nanolayer located between the first electrode and the photoelectric conversion layer.

2. 2. The photoelectric conversion element according to claim 1, wherein the charge mobility of the organic auxiliary layer is 100 times or more higher than the charge mobility of the photoelectric conversion layer.

3. 2. The photoelectric conversion element according to claim 1, wherein the charge mobility of the second organic material is 100 times or more higher than the charge mobility of the first organic material.

4. The charge mobility of the second organic material is 1.0×10 －３ cm ２ 2. The photoelectric conversion element according to claim 1, wherein the voltage Vs is 1. / Vs or more.

5. 2. The photoelectric conversion element according to claim 1, wherein the fused polycyclic heteroaromatic compound contains S, Se, Te, or a combination thereof.

6. the photoelectric conversion layer further includes a p-type semiconductor or an n-type semiconductor that forms a p-n junction with the first organic material, The photoelectric conversion element according to claim 1 , wherein the organic auxiliary layer further includes the p-type semiconductor or the n-type semiconductor.

7. 7. The photoelectric conversion element according to claim 6, wherein the p-type semiconductor or the n-type semiconductor contains a fullerene or a fullerene derivative.

8. 2. The photoelectric conversion element according to claim 1, wherein the organic auxiliary layer has a thickness of 5 nm or less. 。

9. 2. The photoelectric conversion element according to claim 1, wherein the inorganic nanolayer contains a lanthanum group element, calcium (Ca), potassium (K), aluminum (Al), or an alloy thereof.

10. 10. The photoelectric conversion element according to claim 9, wherein the lanthanum group element includes ytterbium (Yb).

11. 2. The photoelectric conversion element according to claim 1, wherein the inorganic nanolayer has a thickness of 5 nm or less.

12. the organic auxiliary layer is in contact with the photoelectric conversion layer, The photoelectric conversion element according to claim 1 , wherein the inorganic nanolayer is in contact with the first electrode.

13. the first electrode is a cathode; 2. The photoelectric conversion element according to claim 1, wherein the second electrode is an anode.

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

15. An organic sensor comprising the photoelectric conversion element according to claim 1 .

16. An electronic device comprising the organic sensor of claim 15.

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