Organic optoelectronic device and image sensor including the same

Abstract

The present invention relates to an organic photoelectric device and an image sensor including the same. Provided is an IR organic photoelectric device having a simplified device structure and manufactured by a simple process. The IR organic photoelectric device includes an anode and a cathode facing each other, and an infrared absorption and hole transport composite single layer disposed between the anode and the cathode.

Description

Technical Field

[0001] Disclosed are an organic photoelectric device and a stacked image sensor including the same. Background Art

[0002] There is a growing demand for further improving the performance of conventional silicon photodiode-based CMOS image sensors or adding new applications thereof. In particular, research is actively being conducted on infrared (IR) wavelength absorption for extending the conventional RGB color image sensing area through technical improvements regarding low-light sensitivity enhancement and absorption wavelength variation. In other words, a method of improving sensitivity in low-light situations by adding infrared absorption to RGB color images may be a representative example.

[0003] According to a recent article published by Panasonic (Mpixel Organic Film Stack RGB-IR Image Sensor with Electrically Controllable IR Sensitivity, 2017 IEEE International Solid-State Circuits Conference), research is being conducted to develop a sensor for night vision and non-destructive inspection by positioning the infrared absorption layer below the visible absorption layer while realizing the RGB+IR mode according to a variable voltage.

[0004] In addition, checking the cross-section of the diode structure manufactured by Panasonic, the lower buffer layer, the infrared absorption layer, the visible absorption layer and the upper buffer layer are sequentially stacked on the lower electrode, and the upper electrode is formed thereon. In other words, in order to enhance infrared absorption, in addition to the conventional photodiode structure of the buffer layer / visible absorption layer, a stacking process of an organic material absorption layer is added by additionally including an infrared absorption layer. In particular, due to the difference in organic molecular structure and properties between the visible absorption layer and the infrared absorption layer, the diode structure has a dual system driven by visible light at a low voltage (intermediate voltage) but simultaneously driven by visible light and infrared at a high voltage, and thus shows dependence on the operating voltage when the sensor is driven, and is therefore restrictively used in mobile image sensors that particularly require low voltage drive. Summary of the invention

[0005] One embodiment provides an IR organic photoelectric device having a simplified device structure and manufactured through a simple process.

[0006] Another embodiment provides a stacked RGB-IR image sensor including the organic photoelectric device.

[0007] Yet another embodiment provides a stacked UV-IR image sensor including the organic photoelectric device.

[0008] According to one embodiment, an IR organic optoelectronic device includes an anode and a cathode facing each other, and an infrared absorption and hole transport composite single layer between the anode and the cathode.

[0009] According to another embodiment, an organic image sensor includes an anode and a cathode facing each other, a visible absorption layer or a UV absorption layer disposed between the anode and the cathode, and an infrared absorption and hole transport composite single layer disposed between the anode and the visible absorption layer or the UV absorption layer.

[0010] IR organic optoelectronic devices may have a simplified device structure and may be manufactured through a simple process.

[0011] An RGB-IR image sensor that can be driven at a low voltage and has improved sensitivity in low illumination can be provided.

[0012] A UV-IR image sensor that can be driven at a low voltage and simultaneously sense ultraviolet (UV) rays and infrared rays may be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a cross-sectional view of an IR organic photoelectric device according to an embodiment,

[0014] Figure 2 It is shown Figure 1 Diagram of the energy levels of IR organic optoelectronic devices,

[0015] Figure 3 It is shown Figure 1 Another energy level diagram of an IR organic optoelectronic device,

[0016] Figure 4 is a cross-sectional view of an RGB-IR organic image sensor according to another embodiment,

[0017] Figure 5 It is shown Figure 4 Diagram of the energy levels of an RGB-IR organic image sensor,

[0018] Figure 6 It is shown Figure 4 Another graph of the energy levels of an RGB-IR organic image sensor,

[0019] Figure 7 yes Figure 4 Schematic top view of the RGB-IR image sensor.

[0020] Figure 8 yes Figure 4 Another schematic top view of an RGB-IR image sensor,

[0021] Fig. 9 yes Figure 4 Another schematic top view of an RGB-IR image sensor,

[0022] Fig.10 is a cross-sectional view of a UV-IR organic image sensor according to another embodiment,

[0023] Fig.11 is a graph showing the absorption coefficient of a co-deposited thin film of a hole transport material and a metal oxide,

[0024] Fig.12 is a graph showing the extinction coefficient of a metal oxide thin film,

[0025] Fig.13 is a graph showing external quantum efficiency (EQE) depending on wavelength of image sensors according to Examples 1 and 2 and Comparative Example 1,

[0026] Fig.14 is a graph showing external quantum efficiency (EQE) depending on wavelength of image sensors according to Examples 3 and 4 and Comparative Example 2,

[0027] Fig.15A , 15B , 15C and 15D are cross-sectional views of organic image sensors according to some example embodiments; and

[0028] Fig.16 is a schematic diagram of an electronic device 1600 according to some example embodiments. DETAILED DESCRIPTION

[0029] Hereinafter, example embodiments will be described in detail to enable those skilled in the art to understand the example embodiments. However, the present disclosure may be implemented in many different forms and should not be construed as limited to the example embodiments set forth herein.

[0030] In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like reference numerals denote like elements throughout the specification. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element, or there can be intervening elements. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0031] As used herein, when no definition is otherwise provided, the term "substituted" refers to a substance substituted with a substituent such as a halogen (F, Br, Cl or I), a hydroxyl group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazine group, a hydrazo 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 C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C30 aryl group, a C7 to C30 aralkyl group, a C1 to C4 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroaralkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, a C2 to C20 heterocycloalkyl group, and combinations thereof, replacing the hydrogen of the compound.

[0032] Figure 1 is a cross-sectional view of an IR organic photoelectric device according to an embodiment.

[0033] Reference Figure 1 According to an embodiment, an IR organic photoelectric device 100 includes a first electrode 10 and a second electrode 20 facing each other, and an infrared absorption and hole transport composite monolayer 30 disposed between the first electrode 10 and the second electrode 20. An electron transport layer 40 is disposed between the infrared absorption and hole transport composite monolayer 30 and the second electrode 20 (which may be a cathode or an anode).

[0034] One of the first electrode 10 and the second electrode 20 is an anode and the other is a cathode. At least one of the first electrode 10 and the second electrode 20 may be a light-transmitting electrode, and the light-transmitting electrode may be made of, for example, a transparent conductor such as indium tin oxide (ITO) or indium zinc oxide (IZO), or may be made of a single-layer metal thin film layer or a multilayer having a thin thickness. When one of the first electrode 10 and the second electrode 20 is a non-light-transmitting electrode, it may be made of, for example, an opaque conductor such as aluminum (Al).

[0035] The infrared absorption and hole transport composite monolayer 30 absorbs light in the infrared region, separates holes from excitons generated by light absorption, and transports the holes to the anode 10. In other words, the infrared absorption and hole transport composite monolayer 30 plays the role of absorbing light in the infrared wavelength region while separating holes from excitons generated by light absorption, thereby transporting them to the anode 10. In addition, the infrared absorption and hole transport composite monolayer 30 can be configured to increase the number ("amount") of holes moving to the anode 10 and sense low illumination through infrared absorption, thereby improving the efficiency of the organic optoelectronic device 100 and any other electronic device (e.g., image sensor) including the organic optoelectronic device 100.

[0036] The infrared absorption and hole transport composite single layer 30 is formed by co-depositing a hole transport material (HTL) and a metal oxide, and thus can exhibit infrared absorption capability as well as a hole transport function. Therefore, it will be understood that the infrared absorption and hole transport composite single layer 30 can include a hole transport material (HTL) and a metal oxide.

[0037] The hole transport material (HTL) may have a highest occupied molecular orbital (HOMO) energy level between the work function of the anode and the work function of the metal oxide. Figure 2 As shown, the hole transport material (HTL) has transparency capable of transmitting visible light due to an energy band gap greater than or equal to about 2.8 eV, and can separate and transport holes due to the HOMO energy level between the work function of the anode and the work function of the metal oxide. Here, the HOMO energy level represents the absolute value of the HOMO energy level when the vacuum energy level is 0 eV.

[0038] When the term "about" or "substantially" is used in conjunction with a numerical value in this specification, it means that the relevant numerical value includes a tolerance of ±10% around the numerical value. When a range is specified, the range includes all numerical values ​​therebetween in increments such as 0.1%.

[0039] The hole transport material may have, for example, an energy band gap of about 2.8 eV to about 4.0 eV, and the hole transport material may be a material configured to transport visible light based on the hole transport material having an energy band gap of about 2.8 eV to about 4.0 eV.

[0040] The difference (Δd1) between the HOMO energy level of the hole transport material and the work function of the metal oxide may be, for example, about 0.01 eV to about 0.89 eV. Figure 2 The difference (Δd1) between the HOMO energy level of the hole transport material and the work function of the metal oxide may be (5.7-5.16)=0.54 eV. Figure 3 The difference (Δd1) between the HOMO energy level of the hole transport material and the work function of the metal oxide may be (6.1-5.16)=0.84 eV. The HOMO energy level of the hole transport material may be, for example, greater than about 4.7 eV and less than or equal to about 5.6 eV.

[0041] The hole transport material is an amino compound, such as 4,4',4"-tri(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine, N,N-diphenyl-N,N-bis(9-phenyl-9H-carbazole-3-yl)biphenyl-4,4'-diamine, N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluorene-2-amine, di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane, 9,9-bis[4-N,N-bis-biphenyl-4-yl-aminophenyl]-9H-fluorene, etc., but are not limited thereto.

[0042] In some example embodiments, the metal oxide may have a work function at a level greater than about 5.6 eV. The metal oxide may be a material having a work function lower than the HOMO level of the hole transport material, and may have a work function greater than about 5.6 eV. In one embodiment, the work function may range from about 5.7 eV to about 6.0 eV. Figure 2 The energy diagram for molybdenum oxide (MoOx) having a work function level of about 5.7 eV is shown, Figure 3 The energy diagrams are shown for rhenium oxide (ReOx) having a work function level of about 6.0 eV, but they are not limited thereto. Figure 2 and 3 In FIG, HTL and metal oxides (MoOx and ReOx) are shown separately for better understanding and ease of description, but are actually co-deposited together, and thus, their energy diagrams may be mixed.

[0043] The hole transport material included in the infrared absorption and hole transport composite monolayer 30 may be included in an amount less than or equal to about 50 volume % based on the infrared absorption and hole transport composite monolayer 30. Within this range, it may be included in an amount of about 0.01 volume % to about 20 volume %, for example, about 0.01 volume % to about 10 volume %.

[0044] The metal oxide included in the infrared absorbing and hole transporting composite monolayer 30 may be included in an amount greater than or equal to about 50 volume % based on the infrared absorbing and hole transporting composite monolayer 30. Within this range, it may be included in an amount of about 80 volume % to about 99.9 volume %, e.g., about 90 volume % to about 99.9 volume %, e.g., about 90 volume % to about 99 volume %.

[0045] The electron transport layer 40 plays a role of separating electrons of excitons generated by the infrared absorption and hole transport composite monolayer 30 and transporting them toward the cathode 20, but it does not substantially absorb light in the visible region. In other words, the electron transport layer 40 plays the role of increasing the number ("amount") of electrons moving toward the cathode 20, thereby improving the efficiency of the organic photoelectric device 100.

[0046] Therefore, the electron transport layer 40 may be composed of an electron transport material. The electron transport material has transparency capable of transmitting visible light due to an energy band gap greater than or equal to about 2.8 eV, and has a LUMO energy level between the work function of the cathode 20 and the LUMO energy level of the visible light absorber. Here, the LUMO energy level represents the absolute value of the LUMO energy level when the vacuum energy level is 0 eV. The electron transport material may have, for example, an energy band gap of about 2.8 eV to about 4.0 eV.

[0047] like Figure 2 and 3 As shown, the LUMO energy level of the electron transport layer 40 may have a work function higher than the work function of the second electrode 20 as a cathode. The LUMO energy level of the electron transport material may be, for example, greater than about 3.6 eV and less than 4.3 eV. For example, the difference (Δd2) between the LUMO energy level of the electron transport layer 40 and the LUMO energy level (about 2.26 eV) of the infrared absorption and hole transport composite monolayer 30 may be, for example, about 0.01 eV to about 0.84 eV.

[0048] The electron transport material may be, for example, a carboxylic anhydride, such as 1,4,5,8-naphthalenetetracarboxylic dianhydride, but is not limited thereto.

[0049] Figure 1 The IR organic optoelectronic device shown can be applied to image sensors for digital cameras, image sensors for cameras for mobile phones, infrared cameras, image sensors for CCTV, image sensors for cameras for PC communications, X-ray detection sensors, etc., but is not limited thereto.

[0050] Figure 4 is a cross-sectional view of an organic stacked RGB-IR image sensor 1000 according to another embodiment. Figure 5 and 6 Different energy diagrams of organic stacked RGB-IR image sensors are shown, Figures 7 to 9 2. Schematic diagram of an organic stacked RGB-IR image sensor with different top views.

[0051] Reference Figure 4 The organic stacked RGB-IR image sensor 1000 includes a first electrode 10 and a second electrode 20, and a visible absorption layer 50 disposed between the first electrode 10 and the second electrode 20. The visible absorption layer 50 includes an infrared absorption and hole transport composite monolayer 30 on one surface and an electron transport layer 40 on the other surface. Figure 4 As shown, the infrared absorption and hole transport composite monolayer 30 is between the first electrode 10 and the second electrode 20. The infrared absorption and hole transport composite monolayer 30 is related to the above reference Figures 1 to 3The infrared absorption and hole transport composite monolayer 30 described herein has the same or similar properties, components, characteristics, some combination thereof, etc., so the detailed description of the infrared absorption and hole transport composite monolayer 30 will not be referred to herein. Figures 4 to 6 repeat.

[0052] One of the first electrode 10 and the second electrode 20 is an anode and the other is a cathode. At least one of the first electrode 10 and the second electrode 20 may be a light-transmitting electrode, and the light-transmitting electrode may be made of, for example, a transparent conductor such as indium tin oxide (ITO) or indium zinc oxide (IZO) (may at least partially include, for example, a transparent conductor such as indium tin oxide (ITO) or indium zinc oxide (IZO)), or may be made of a single-layer metal thin film layer or a multilayer having a thin thickness. When one of the first electrode 10 and the second electrode 20 is a non-light-transmitting electrode, it may be made of, for example, an opaque conductor such as aluminum (Al) (may at least partially include, for example, an opaque conductor such as aluminum (Al)).

[0053] The visible absorption layer 50 includes a visible light absorber that absorbs light in a specific wavelength region of the visible region.

[0054] The visible light absorber may selectively absorb light in a green wavelength region, a blue wavelength region, or a red wavelength region in the visible region as an n-type semiconductor or a p-type semiconductor, and may have a maximum absorption wavelength (λmax) in the range of about 400 nm to about 700 nm.

[0055] When absorbing light in a green wavelength region, the visible light absorber may be a compound represented by Chemical Formula 1 (subphthalocyanine derivative).

[0056] [Chemical formula 1]

[0057]

[0058] In Chemical Formula 1,

[0059] R 1 To R 12 are independently hydrogen, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C6 to C30 aryl, substituted or unsubstituted C3 to C30 heteroaryl, a halogen atom, a halogen-containing group or a combination thereof, and

[0060] X is an anion.

[0061] The compound represented by the chemical formula is a visible light absorber having a maximum absorption wavelength (λmax) in the range of about 500 nm to about 600 nm, and has wavelength selectivity in a green wavelength region.

[0062] The compound represented by Chemical Formula 1 may be used as an n-type semiconductor or a p-type semiconductor, and may be contained alone as a visible light absorber without an additional p-type semiconductor or n-type semiconductor forming a pn junction.

[0063] The compound represented by Chemical Formula 1 may be, for example, one of the compounds represented by Chemical Formulas 1a to 1e, but is not limited thereto.

[0064]

[0065] When absorbing light in the red wavelength region, the visible light absorber may be CuPc (copper phthalocyanine) or ZnPc (zinc phthalocyanine).

[0066] When absorbing light in the blue wavelength region, the visible light absorber may be BP3T (biphenyl terthiophene) or C 60 .

[0067] The infrared absorption and hole transport composite monolayer 30 absorbs light in the infrared region, and then separates holes of excitons generated by the infrared absorption from holes of excitons generated by the visible light absorption of the visible absorption layer 50, thereby transporting them toward the anode 10. Therefore, the infrared absorption and hole transport composite monolayer 30 plays the role of increasing the number of holes moving toward the anode 10 and improving low-illuminance sensitivity through infrared absorption, thereby improving the efficiency of the organic optoelectronic device 100 and thus improving the efficiency of any electronic device (e.g., image sensor) including the organic optoelectronic device 100.

[0068] The infrared absorption and hole transport composite single layer 30 formed by co-depositing the hole transport material and the metal oxide may exhibit infrared absorption capability as well as hole transport function.

[0069] like Figure 5 As shown, the hole transport material (HTL) has transparency capable of transmitting light due to an energy band gap of greater than or equal to about 2.8 eV, and can separate and transport holes due to a HOMO energy level (e.g., a HOMO energy level of about 5.16 eV) between the work function of the anode 10 and the work function of the metal oxide. Here, the HOMO energy level refers to the absolute value of the HOMO energy level when the vacuum energy level is 0 eV.

[0070] The hole transport material may have an energy band gap of, for example, about 2.8 eV to about 4.0 eV.

[0071] The HOMO energy level of the hole transport material (e.g., about 5.16 eV) and the work function of the metal oxide (e.g., Figure 5 As shown in Figure 5, Figure 6The difference between about 6.0 eV shown) can be, for example, about 0.01 eV to about 0.89 eV, such as about 0.01 eV to about 0.84 eV. The HOMO level of the hole transport material can be, for example, greater than about 4.7 eV and less than or equal to about 5.6 eV.

[0072] The hole transport material is an amino compound, such as 4,4',4"-tris(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine, N,N-diphenyl-N,N-bis(9-phenyl-9H-carbazole-3-yl)biphenyl-4,4'-diamine, N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluorene-2-amine, di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane, or 9,9-bis[4-N,N-bis-biphenyl-4-yl-aminophenyl]-9H-fluorene, etc., but are not limited thereto.

[0073] In some example embodiments, the metal oxide may have a work function level greater than about 5.6 eV. The metal oxide may be a material having a work function lower than the HOMO level of the hole transport material, and may have a work function greater than about 5.6 eV. In one embodiment, the work function may range from about 5.7 eV to about 6.0 eV. Figure 5 The energy diagram for molybdenum oxide (MoOx) having a work function level of about 5.7 eV is shown, Figure 6 The energy diagrams are shown for rhenium oxide (ReOx) having a work function level of about 6.0 eV, but they are not limited thereto.

[0074] The hole transport material included in the infrared absorption and hole transport composite monolayer 30 may be included in an amount less than or equal to about 50 volume % based on the infrared absorption and hole transport composite monolayer 30. Within this range, it may be included in an amount of about 0.01 volume % to about 20 volume %, for example, about 0.01 volume % to about 10 volume %.

[0075] The metal oxide included in the infrared absorbing and hole transporting composite monolayer 30 may be included in an amount greater than or equal to about 50 volume % based on the infrared absorbing and hole transporting composite monolayer 30. Within this range, it may be included in an amount of about 80 volume % to about 99.9 volume %, e.g., about 90 volume % to about 99.9 volume %, e.g., about 90 volume % to about 99 volume %.

[0076] The electron transport layer 40 may be configured to separate the electrons of the excitons generated by the infrared absorption and hole transport composite monolayer 30 and the visible absorption layer 50 to transport them toward the cathode 20, but it does not substantially absorb light in the visible region. In other words, the electron transport layer 40 plays the role of increasing the number of electrons moving toward the cathode 20, thereby improving the efficiency of the RGB-IR image sensor 1000, and thus improving the performance of any electronic device including the RGB-IR image sensor 1000.

[0077] Therefore, the electron transport layer 40 may be composed of an electron transport material. The electron transport material has transparency capable of transmitting visible light due to an energy band gap greater than or equal to about 2.8 eV, and has a LUMO energy level between the work function of the cathode 20 and the LUMO energy level of the visible light absorber. Here, the LUMO energy level represents the absolute value of the LUMO energy level when the vacuum energy level is 0 eV. The electron transport material may have, for example, an energy band gap of about 2.8 eV to about 4.0 eV.

[0078] like Figure 5 and 6 As shown, the LUMO energy level of the electron transport layer 40 may be between the work function of the second electrode 20 as a cathode and the LUMO energy level of the visible absorption layer 50. The LUMO energy level of the electron transport material may be, for example, greater than about 3.6 eV and less than 4.3 eV. For example, the difference (Δd3) between the LUMO energy level of the electron transport layer 40 and the LUMO energy level of the visible absorption layer 50 may be, for example, about 0.01 eV to about 0.84 eV.

[0079] The electron transport material may be, for example, a carboxylic anhydride, such as 1,4,5,8-naphthalenetetracarboxylic dianhydride, but is not limited thereto.

[0080] Figures 7 to 9 1 is a top view showing various aspects of the organic stacked RGB-IR image sensor 1000. Figure 7 As shown, the organic stacked RGB-IR image sensor 1000 can be formed by arranging a red organic photoelectric device 55R, a green organic photoelectric device 55G, and a blue organic photoelectric device 55B in a single layer in a Bayer shape on an IR organic photoelectric device 100 including an infrared absorption and hole transport composite single layer 30. Each organic photoelectric device 55R, 55B, 55G may include a separate visible absorption layer 50 configured to absorb different wavelength line regions of visible light. Figure 7 Formed in that way, all image sensors are formed as organic layers to realize a flexible image sensor.

[0081] On the other hand, Figure 8As shown, the organic stacked RGB-IR image sensor 1000 has a structure in which a red organic photoelectric device, a green organic photoelectric device, and a blue organic photoelectric device are stacked on an IR organic photoelectric device including an infrared absorption and hole transport composite single layer 30, thereby reducing the size and crosstalk, thereby improving the performance of the image sensor 1000. In addition, as Fig. 9 As shown, by forming a green organic photoelectric device (55G) as one layer on an IR organic photoelectric device including an infrared absorption and hole transport composite single layer 30 and forming a red organic photoelectric device (55R) and a blue organic photoelectric device (55B) arranged in a Bayer shape as another layer, the sensitivity of the organic stacked RGB-IR image sensor 1000 can be greatly improved.

[0082] Reference Figures 4 to 9 Unlike conventional image sensors in which an infrared absorption layer and a hole transport buffer layer are formed as two layers, the organic stacked RGB-IR image sensor 1000 includes an infrared absorption and hole transport composite monolayer 30 formed as a single film, and thus can simultaneously absorb visible light (visible wavelength line region of incident light 92) and infrared light (infrared wavelength line region of incident light 92) under low voltage driving conditions (e.g., about 3V). Therefore, the sensitivity under low illumination can be improved. Therefore, the organic stacked RGB-IR image sensor 1000 can be used as a sensor for night vision or non-destructive inspection.

[0083] Fig.10 is a cross-sectional view of an organic stacked UV-IR image sensor including an IR organic photoelectric device.

[0084] Reference Fig.10 In addition to forming the non-visible absorption layer 2050, specifically, in addition to forming a UV absorption layer instead of Figure 4 The organic stacked UV-IR image sensor 2000 has the same basic structure as the organic stacked RGB-IR image sensor 1000 except for the visible absorption layer 50 in the organic stacked RGB-IR image sensor 1000 shown. For example, the infrared absorption and hole transport composite single layer 30 may have the same structure as described above with reference to FIG. Figure 4-6 and Figure 1-3 The infrared absorption and hole transport composite monolayer 30 described above has the same or similar properties, components, characteristics, some combinations thereof, etc., so the detailed description of the infrared absorption and hole transport composite monolayer 30 will not be referred to here. Fig.10In unity, the visible absorption layer 50 and the UV absorption layer 2050 may be referred to as an absorption layer, so that it will be understood that the organic image sensor (e.g., image sensor 1000, image sensor 2000, etc.) may include a first electrode 10 and a second electrode 20 facing each other, an absorption layer between the first electrode 10 and the second electrode 20, and an infrared absorption and hole transport composite single layer between the anode and the absorption layer in the first electrode 10 and the second electrode 20. Figure 4 As shown, the absorbent layer may be a visible absorbent layer 50. Fig.10 As shown, the absorbing layer can be a UV absorbing layer 2050.

[0085] The non-visible light (UV) absorbing layer 2050 may be formed of an n-type material capable of absorbing UV, or a BHJ (bulk heterojunction) type material prepared by mixing n-type and p-type materials. The non-visible light absorbing material may include NTCDA (naphthalene tetracarboxylic dianhydride), NTCDI (naphthalene tetracarboxylic diimide), and the like.

[0086] Fig.10 The organic stacked UV-IR image sensor 2000 shown absorbs UV light (incident light 92 in the UV wavelength line region) and infrared light (incident light 92 in the infrared wavelength line region) simultaneously under low voltage driving conditions, and can therefore be applied to diagnostic sensors, special sensors, and the like.

[0087] Hereinafter, the present disclosure is described in more detail with reference to examples. However, these examples are exemplary, and the present disclosure is not limited thereto.

[0088] Measurement of light absorption properties

[0089] The light absorption characteristics in the thin film state were evaluated by preparing sample 1 (①), sample 2 (②) and sample 3 (③), and then measuring their extinction coefficients by irradiating visible light-infrared (Vis-IR) using a Cary 5000 UV spectrometer (Varian Medical Systems Inc.). Sample 1 (①) was subjected to ultraviolet light irradiation under high vacuum (<10 -7 0.5 to TNATA (4,4',4"-tri(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine) [highest occupied molecular orbital (HOMO) energy level: 5.16 eV] was thermally evaporated at a rate of 1:1 to form a 80 nm thick film, sample 2 (②) was obtained by co-depositing TNATA [highest occupied molecular orbital (HOMO) energy level: 5.16 eV] and rhenium oxide (ReOx) [work function: 6.0 eV] in a volume ratio of 1:1 under the same conditions, and sample 3 (③) was obtained by co-depositing TNATA [highest occupied molecular orbital (HOMO) energy level: 5.16 eV] and molybdenum oxide (MoOx) [work function: 5.7 eV] in a volume ratio of 1:1 under the same conditions. The results are shown in Figure 2. Fig.11 shown.

[0090] On the other hand, sample (④) was prepared by depositing only rhenium oxide (ReOx) [work function: 6.0 eV], and sample (⑤) was prepared by depositing only molybdenum oxide (MoOx) [work function: 5.7 eV] under the same conditions, and then their extinction coefficients were measured in the same manner as above. The results are as follows: Fig.12 shown.

[0091] Reference Fig.11 and 12 The results of ①, ④ and ⑤ show that infrared absorption capability cannot be obtained only by the hole transport material (TNATA) or the metal oxide (MoOx or ReOx). In contrast, the co-deposited thin film of the hole transport material (TNATA) and rhenium oxide (②) or the co-deposited thin film of the hole transport material (TNATA) and molybdenum oxide (③) exhibits the ability to absorb light in the short-wavelength infrared region ranging from 1000nm to 1500nm.

[0092] External Quantum Efficiency (EQE) Measurement

[0093] Example 1: Fabrication of RGB-IR reflective image sensor

[0094] ITO (work function: 4.7 eV) is sputtered on a glass substrate to form an anode of about 100 nm thick, and then TNATA and molybdenum oxide (MoOx) are co-deposited thereon in a volume ratio of 1: 1 to form a 50 nm thick infrared absorption and hole transport composite monolayer. Subsequently, the compound represented by chemical formula 1a is deposited to form a visible absorption layer. On the visible absorption layer, a 50 nm thick active layer is formed. Subsequently, on the active layer, an electron transport layer is formed of 1,4,5,8-naphthalenetetracarboxylic dianhydride, and then aluminum (Al) is thermally evaporated to form a 70 nm thick cathode, thereby manufacturing an RGB-IR reflective image sensor.

[0095] Example 2: Fabrication of RGB-IR reflective image sensor

[0096] The RGB-IR reflective image sensor was manufactured according to the same method as Example 1, except that a 50 nm thick infrared absorption and hole transport composite single layer was formed by co-depositing TNATA and rhenium oxide (ReOx) in a volume ratio of 1:1.

[0097] Comparative Example 1: Fabrication of a Reflective Image Sensor

[0098] The reflective image sensor was manufactured according to the same method as Example 1, except that the hole transport layer was formed by depositing TNATA to a thickness of 50 nm on the anode instead of the infrared absorption and hole transport composite single layer.

[0099] Example 3: Fabrication of RGB-IR Transmissive Image Sensor

[0100] An anode of about 100 nm thick is formed by sputtering ITO on a glass substrate, and a 50 nm thick infrared absorption and hole transport composite monolayer is formed on the anode by co-depositing TNATA and molybdenum oxide (MoOx) in a volume ratio of 1: 1. Subsequently, a visible absorption layer is formed by depositing a compound represented by chemical formula 1a. On the visible absorption layer, a 50 nm thick active layer is formed. On the active layer, an electron transport layer is formed by 1,4,5,8-naphthalenetetracarboxylic dianhydride, and a cathode of about 70 nm thick is formed on the electron transport layer by sputtering ITO to manufacture an RGB-IR transmissive image sensor.

[0101] Example 4: Fabrication of RGB-IR Transmissive Image Sensor

[0102] The RGB-IR transmissive image sensor was manufactured according to the same method as Example 3, except that a 50 nm thick infrared absorption and hole transport composite single layer was formed by co-depositing TNATA and rhenium oxide (ReOx) in a volume ratio of 1:1.

[0103] Comparative Example 2: Fabrication of a Transmissive Image Sensor

[0104] The transmissive image sensor was manufactured according to the same method as Example 3, except that the hole transport layer was formed by depositing TNATA to a thickness of 50 nm on the anode instead of the infrared absorption and hole transport composite single layer.

[0105] External Quantum Efficiency (EQE) Measurement

[0106] The external quantum efficiency (EQE) was measured by using an IPCE measurement system (McScience Inc., Korea). First, the IPCE measurement system was calibrated by using a Si photodiode (Hamamatsu Photonics Co., Ltd., Japan), and then installed on each image sensor according to Examples 1 to 4 and Comparative Examples 1 and 2, and their external quantum efficiencies in a wavelength range from about 400 to 1800 nm were measured.

[0107] Fig.13 is a graph showing external quantum efficiency (EQE) depending on wavelength of image sensors according to Examples 1 and 2 and Comparative Example 1, Fig.14 is a graph showing external quantum efficiency (EQE) at 3 V depending on wavelength of image sensors according to Examples 3 and 4 and Comparative Example 2.

[0108] Reference Fig.13 and 14 , the organic photoelectric devices according to Examples 1 to 4 showed sufficient external quantum efficiency (EQE) in a green wavelength region of about 500 nm to 600 nm and simultaneously in a short wavelength infrared (SWIR) region of 1000 to 1500 nm.

[0109] In addition, because the external quantum efficiency (EQE) of short-wavelength infrared rays is shown to be greater than or equal to 10% at a driving voltage of 1V or 3V ( Fig.14 ) or greater than or equal to 30% ( Fig.13 ), so the organic photoelectric devices according to Examples 1 to 4 were proven to be driven at a low voltage.

[0110] Fig.15A , 15B 15C and 15D are cross-sectional views of organic image sensors according to some example embodiments.

[0111] Generally refer to Figures 15A-15D , the organic image sensor 1500A, 1500B, 1500C, and / or 1500D may include a first electrode 10 and a second electrode 20 facing each other. In the illustrated example embodiment, the first electrode 10 may be an anode and the second electrode 20 may be a cathode, but example embodiments are not limited thereto. Figures 15A-15DAs further shown in FIG. 1 , the organic image sensor 1500A, 1500B, 1500C, and / or 1500D may include one or more absorption layers 60 between the first electrode 10 and the second electrode 20 and an infrared absorption and hole transport composite monolayer 30 between the first electrode 10 (e.g., an anode) and the absorption layer 60. The organic image sensor 1500A, 1500B, 1500C, and / or 1500D may also include an electron transport layer 40 between the second electrode 20 (e.g., a cathode) and the absorption layer 60, although the electron transport layer 40 may be omitted from the organic image sensor 1500A, 1500B, 1500C, and / or 1500D in some example embodiments.

[0112] In some example embodiments, the absorption layer 60 may be a single continuous layer. For example, the absorption layer 60 may be a single visible absorption layer 50 or a single UV absorption layer 2050.

[0113] Now refer to Figures 15A-15D , the absorption layer 60 may include a plurality of layers 60-1 to 60-N (N is a positive integer). At least two individual layers of the layers 60-1 to 60-N may be configured to absorb different wavelength line regions of the incident light 92. For example, at least one layer of the layers 60-1 to 60-N may be configured to absorb a visible wavelength line region of the incident light, and at least one individual layer of the layers 60-1 to 60-N may be configured to absorb a non-visible wavelength line region of the incident light, the non-visible wavelength line region being an ultraviolet wavelength line region or an infrared wavelength line region. At least two layers of the layers 60-1 to 60-N may be configured to absorb different non-visible wavelength line regions of the incident light, each non-visible wavelength line region being an ultraviolet wavelength line region or an infrared wavelength line region.

[0114] Different layers of the layers 60-1 to 60-N may be stacked in the vertical direction D1 and / or the horizontal direction D2. As shown, the direction D1 extends orthogonally or substantially orthogonally (e.g., orthogonally within manufacturing tolerances and / or material tolerances) to the surface 30S of the infrared absorption and hole transport composite monolayer 30, and the direction D2 extends parallel or substantially parallel to (e.g., parallel to within manufacturing tolerances and / or material tolerances) the surface 30S. Different layers 60-1 to 60-N may be configured to absorb different wavelength line regions of the incident light 92. Such different wavelength line regions may include one or more visible wavelength line regions, one or more infrared wavelength line regions, and one or more ultraviolet wavelength line regions. Each individual layer 60-1 to 60-N may be a different one of the visible absorption layer 50 or the UV absorption layer 2050. In some example embodiments, the individual layers 60-1 to 60-N may be different visible absorption layers 50 configured to absorb different wavelength line regions of the incident light 92. For example, at least some of the individual layers 60-1 to 60-N may be different ones of the absorption layers of the organic optoelectronic devices 55G, 55B, and / or 55R. In some example embodiments, the individual layers 60-1 to 60-N may be different UV absorption layers configured to absorb different wavelength line regions of the incident light 92.

[0115] like Fig.15A As shown, the absorption layer 60 may include a stack of multiple layers 60-1 to 60-N, which include layers 60-2 to 60-N stacked horizontally (e.g., in direction D2) relative to each other and stacked vertically (e.g., in direction D1) together on the layer 60-1. Fig.15A As shown, layers 60-2 to 60-N can be stacked horizontally so that the top surfaces of layers 60-2 to 60-N are coplanar or substantially coplanar with each other (e.g., coplanar within manufacturing tolerances and / or material tolerances) and / or so that the bottom surfaces of layers 60-2 to 60-N are coplanar or substantially coplanar with each other.

[0116] In some example embodiments, including Figures 15A-15B In the example embodiment shown in , layers 60-2 to 60-N may be absorption layers, each of which is configured to absorb one or more different wavelength line regions of incident light 92, such that the set of layers 60-2 to 60-N is collectively configured to absorb a collective wavelength line region of incident light 92 that is different from the wavelength line region that layer 60-1 is configured to absorb. For example, in some example embodiments, layers 60-2 to 60-N may be configured to absorb different visible wavelength line regions (e.g., blue light, green light, and red light) of incident light 92, and layer 60-1 may be configured to absorb a UV wavelength line region of incident light 92.

[0117] In some example embodiments, one or more of the absorption layers 60-2 to 60-N may be configured to absorb a wavelength line region different from the visible wavelength line region (e.g., ultraviolet light and / or infrared light). In some example embodiments, one or more of the absorption layers 60-2 to 60-N may be configured to absorb the visible wavelength line region, and one or more of the absorption layers 60-2 to 60-N may be configured to absorb a wavelength line region different from the visible wavelength line region (e.g., ultraviolet light and / or infrared light). In some example embodiments, two or more of the absorption layers 60-2 to 60-N may be configured to absorb a different wavelength line region different from the visible wavelength line region (e.g., one layer may be configured to absorb ultraviolet light and another layer may be configured to absorb infrared light).

[0118] Reference now Fig. 15B , the relative positions of the layers 60-2 to 60-N and the layer 60-1 are relative to each other as shown in FIG. Fig.15A The relative positions shown are reversed so that layer 60-1 is closer to the origin direction of incident light 92 (eg, the incident light side of organic image sensor 1500B) relative to layers 60-2 to 60-N. In some example embodiments, the origin direction of incident light 92 may be relative to Figures 15A-15C , the direction shown in is reversed so that the infrared absorption and hole transport composite single layer 30 is closer to the incident light side of the organic image sensor 1500B, 1500A, 1500C relative to the absorption layer 60, but example embodiments are not limited thereto.

[0119] Now refer to Fig. 15C In some example embodiments, the absorption layer 60 may include only (“only”) a horizontal stack of layers 60-1 to 60-N (e.g., a stack in the D2 direction). Different layers 60-1 to 60-N may be configured to absorb different wavelength line regions of the incident light 92. Such different wavelength line regions may include one or more visible wavelength line regions, one or more infrared wavelength line regions, and one or more ultraviolet wavelength line regions. Fig. 15C As shown, layers 60-1 to 60-N can be stacked horizontally so that the top surfaces of layers 60-1 to 60-N are coplanar or substantially coplanar with each other (e.g., coplanar within manufacturing tolerances and / or material tolerances) and / or so that the bottom surfaces of layers 60-1 to 60-N are coplanar or substantially coplanar with each other.

[0120] Now refer to Fig.15D, the absorption layer 60 may include two or more groups of vertically stacked absorption layers 60-1 to 60-N (e.g., stacked in direction D1), wherein each group of absorption layers 60-1 to 60-Y and 60-(Y+1) to 60-N (Y is a positive integer) includes a plurality of layers stacked horizontally relative to each other (e.g., stacked in direction D2). As further shown, the interfaces between horizontally adjacent layers in a group of layers 60-1 to 60-Y may be horizontally offset by an offset distance "x" from the interfaces between horizontally adjacent layers in a vertically adjacent group of layers 60-(Y+1) to 60-N. In some example embodiments, the offset distance x is a null value, so that the interfaces between horizontally adjacent layers in a group of layers 60-1 to 60-Y are aligned in the vertical direction (direction D1) with the interfaces between horizontally adjacent layers in a vertically adjacent group of layers 60-(Y+1) to 60-N. In some example embodiments, the offset distance is an actual value.

[0121] Fig.16 is a schematic diagram of an electronic device 1600 according to some example embodiments.

[0122] like Fig.16 As shown, the electronic device 1600 may include a processor 1620, a memory 1630, and an image sensor 1640 electrically connected together via a bus 1610. The image sensor 1640 may be an organic image sensor of any example embodiment as described herein. The memory 1630 (which may be a non-transitory computer-readable medium) may store an instruction program. The processor 1620 may execute the stored instruction program to perform one or more functions. For example, the processor 1620 may be configured to process an electrical signal generated by the image sensor 1640. The processor 1620 may be configured to generate an output (e.g., an image to be displayed on a display interface) based on the processed electrical signal.

[0123] While the disclosure has been described in connection with what are presently considered to be practical example embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but on the contrary is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0124] <Description of symbols>

[0125] 10: First electrode 20: Second electrode

[0126] 30: Infrared absorption and hole transport composite monolayer

[0127] 40: electron transport layer 50: visible absorption layer

[0128] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0060395 filed on May 28, 2018, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

Claims

1. An IR organic optoelectronic device, comprising an anode and a cathode facing each other; and an infrared absorption and hole transport composite monolayer between the anode and the cathode, the infrared absorption and hole transport composite monolayer comprising a hole transport material and a metal oxide, wherein the hole transport material is a material having a HOMO energy level between the work function of the anode and the work function of the metal oxide, The amount of the metal oxide in the infrared absorbing and hole transporting composite monolayer is greater than or equal to 50 volume % of the infrared absorbing and hole transporting composite monolayer. 2 . The IR organic optoelectronic device according to claim 1 , wherein the difference between the HOMO level of the hole transport material and the work function of the metal oxide ranges from 0.01 eV to 0.89 eV. 3 . The IR organic optoelectronic device according to claim 1 , wherein the HOMO level of the hole transport material is greater than 4.7 eV and less than or equal to 5.6 eV. 4 . The IR organic photoelectric device according to claim 1 , wherein the hole transport material is a material that transmits visible light due to an energy band gap of 2.8 eV to 4.0 eV.

5. The IR organic optoelectronic device according to claim 1, wherein the metal oxide has a work function level greater than 5.6 eV.

6. The IR organic optoelectronic device according to claim 5, wherein the hole transport material is 4,4',4"-tris(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine, N,N-diphenyl-N,N-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4'-diamine, N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane, or 9,9-bis[4-N,N-bis-biphenyl-4-yl-aminophenyl]-9H-fluorene. 7 . The IR organic photoelectric device according to claim 5 , wherein the metal oxide is molybdenum oxide or rhenium oxide.

8. The IR organic optoelectronic device of claim 1 further comprising an electron transport layer between the cathode and the infrared absorbing and hole transporting composite monolayer.

9. An organic image sensor comprising: an anode and a cathode facing each other; an absorption layer between the anode and the cathode, the absorption layer being a visible absorption layer or an ultraviolet (UV) absorption layer; as well as An infrared absorbing and hole transporting composite monolayer is disposed between the anode and the absorbing layer, wherein the infrared absorbing and hole transporting composite monolayer comprises a hole transporting material and a metal oxide having a work function level greater than 5.6 eV, and The hole transport material is 4,4',4"-tris(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine, N,N-diphenyl-N,N-bis(9-phenyl-9H-carbazole-3-yl)biphenyl-4,4'-diamine, N(diphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluorene-2-amine, di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane, or 9,9-bis[4-N,N-bis-biphenyl-4-yl-aminophenyl]-9H-fluorene. 10 . The organic image sensor according to claim 9 , wherein the hole transport material is a material having a HOMO level between a work function of the anode and a work function of the metal oxide. 11 . The organic image sensor according to claim 10 , wherein a difference between a HOMO level of the hole transport material and a work function of the metal oxide ranges from 0.01 eV to 0.89 eV. 12 . The organic image sensor according to claim 10 , wherein a HOMO level of the hole transport material is greater than 4.7 eV and less than or equal to 5.6 eV. 13 . The organic image sensor according to claim 9 , wherein the hole transport material is a material configured to transmit visible light based on the hole transport material having an energy band gap of 2.8 eV to 4.0 eV.

14. The organic image sensor according to claim 9, wherein the metal oxide is molybdenum oxide or rhenium oxide.

15. The organic image sensor of claim 9, wherein an amount of the metal oxide in the infrared absorbing and hole transporting composite monolayer is greater than or equal to 50 volume % of the infrared absorbing and hole transporting composite monolayer. 16 . The organic image sensor according to claim 9 , further comprising an electron transport layer disposed between the cathode and the visible absorption layer or the UV absorption layer.

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