Infrared organic photoelectric sensor, array, and chip
By regulating the mobility relationship between the electron transport layer and the hole transport layer, the problem of unbalanced carrier mobility in infrared organic photoelectric sensors was solved, improving the device's sensitivity and imaging clarity, and achieving a balance between carrier transport and signal collection.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- GUANGZHOU GUANGDA INNOVATION TECHNOLOGY CO LTD
- Filing Date
- 2025-09-19
- Publication Date
- 2026-05-07
AI Technical Summary
In existing infrared organic photoelectric sensors, the uneven carrier mobility leads to reduced sensitivity and imaging clarity, and focal plane array devices cannot effectively acquire signals.
By adjusting the mobility relationship between the electron transport layer and the hole transport layer to keep them within a reasonable range, a balance between carrier transport, extraction, and collection is ensured. A multilayer structure and an appropriate interface layer are used to achieve low contact resistance and low dark current.
This improves the sensitivity of infrared organic photoelectric sensors and the imaging clarity and resolution of their focal plane array devices, avoiding sensitivity reduction and signal acquisition difficulties caused by excessive mobility differences.
Smart Images
Figure CN2025122425_07052026_PF_FP_ABST
Abstract
Description
An infrared organic photoelectric sensor, array and chip Technical Field
[0001] This invention relates to the field of optoelectronic semiconductor device technology, and more specifically, to an infrared organic optoelectronic sensor, array, and chip. Background Technology
[0002] In organic optoelectronic devices, the electrode / organic semiconductor layer interface plays a crucial role in device performance. Therefore, introducing a carrier transport layer can effectively modify the electrode / organic semiconductor layer interface, thus significantly improving device performance. The carrier mobility of the carrier transport layer is one of the key factors affecting device performance. Carrier mobility is defined as the drift velocity of carriers per unit electric field strength; it is a parameter used to describe the speed of carrier transport.
[0003] Therefore, it is particularly important to improve the performance of devices by controlling the carrier mobility of the carrier transport layer. Summary of the Invention
[0004] The purpose of this invention is to provide an infrared organic photoelectric sensor, array, and chip that balances carrier transport, extraction, and collection within the device by regulating the relationship between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, thereby improving the sensitivity of the infrared organic photoelectric sensor and the imaging clarity and resolution of its focal plane array device.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0006] An infrared organic photoelectric sensor, the infrared organic photoelectric sensor being used for light sensing, the sensor comprising a cathode, an electron transport layer, a photosensitive layer, a hole transport layer, and an anode arranged in sequence;
[0007] The electron mobility of the electron transport layer and the hole mobility of the hole transport layer satisfy the following relationship:
[0008] 0.01≤μ h / μ e ≤100
[0009] Where, μ h μ represents the hole mobility of the hole transport layer. e This represents the electron mobility of the electron transport layer.
[0010] In the infrared organic photoelectric sensor described above, when illuminated, the photosensitive layer generates excitons. After the excitons diffuse to the donor / acceptor interface in the photosensitive layer, they are dissociated into free charges (electrons and holes). Then, the charge carriers are transported through the hole transport layer (HTL) and the electron transport layer (ETL), and finally, the charges are collected by the anode and cathode to form a current generated by photons.
[0011] An appropriate interface layer (hole transport layer, electron transport layer) is needed to form a low contact resistance between the photosensitive layer and the electrode in order to achieve effective charge collection and to prevent the transport of opposite types of charge carriers to achieve low dark current.
[0012] Generally, in photoelectric sensors, excitons are dissociated into free charges (electrons and holes), which are transported to the corresponding electrodes through the hole transport layer and the electron transport layer. If the carrier mobilities of the hole transport layer and the electron transport layer differ too much, holes may be collected by the anode while electrons remain in the electron transport layer. This leads to a decrease in the sensitivity of the infrared organic photoelectric sensor, and may even prevent the readout circuit in the focal plane array device from effectively acquiring the corresponding signal, thus affecting the imaging sharpness and resolution of the focal plane array device. This invention regulates the relationship between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, ensuring that the difference between their electron mobility and hole mobility is within a reasonable range. This ensures and balances carrier transport, extraction, and collection within the device, thereby improving the sensitivity of the infrared organic sensor and the imaging sharpness and resolution of its focal plane array device. Generally, the smaller the difference between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, the higher the sensitivity of the infrared organic photoelectric sensor and the imaging sharpness and resolution of its focal plane array device.
[0013] It should be noted that the infrared organic photoelectric sensor can be mounted upright or inverted.
[0014] The flip-chip structure, from bottom to top, includes a substrate, a cathode near the substrate, an electron transport layer, a photosensitive layer, a hole transport layer, an anode, and an encapsulation layer.
[0015] The mounting structure, from bottom to top, includes a substrate, an anode near the substrate, a hole transport layer, a photosensitive layer, an electron transport layer, a cathode, and an encapsulation layer.
[0016] Both the cathode and anode can be formed from any conductive material.
[0017] Examples of materials used to construct electrodes (cathode and anode) include: metals such as platinum, gold, silver, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, and sodium, or their alloys; metal oxides such as indium oxide and tin oxide, or their composite oxides (e.g., indium tin oxide, indium zinc oxide); conductive polymers such as polyaniline, polypyrrole, polythiophene, and polyacetylene; dopants such as hydrochloric acid, sulfuric acid, sulfonic acid, Lewis acids such as FeCl3, halogen atoms such as iodine, and metal atoms such as sodium and potassium added to the above conductive polymers; and conductive composite materials in which conductive particles such as metal particles, carbon black, fullerenes, and carbon nanotubes are dispersed in a matrix such as a polymer binder. Electrode materials can be used alone or in any combination and ratio of two or more materials.
[0018] Preferably, the electrode has the function of capturing holes and electrons generated within the photosensitive layer. Therefore, among the aforementioned materials, those suitable for capturing holes and electrons are preferred as the constituent materials of the electrode. Examples of electrode materials suitable for capturing holes include, for example, silver and indium tin oxide, which have high work functions. Examples of electrode materials suitable for capturing electrons include, for example, aluminum, which has low work functions.
[0019] Incident light can enter from the bottom or the top of the infrared organic photoelectric sensor.
[0020] For bottom-incidence infrared organic photoelectric sensors, the cathode or anode near the substrate is transparent or partially transparent within the desired wavelength range, and the optical transmittance of the electrode must be higher than 30%. The cathode or anode near the substrate can be a transparent metal oxide (such as indium tin oxide, zinc oxide, and aluminum-doped zinc oxide), or a nitride (such as titanium nitride) and corresponding metal oxynitrides. Furthermore, the anode or cathode near the encapsulation layer can be a thicker metallic material, including, but not limited to, aluminum, silver, titanium, tantalum, molybdenum, copper, chromium, gold, and nickel.
[0021] For top-incidence infrared organic photoelectric sensors, the cathode or anode near the substrate can optimize photosensitivity in a specific wavelength band by reflecting incident light within the desired wavelength range. By selecting a suitable metal material, the required conductivity and optical reflectivity can be obtained simultaneously. Furthermore, the anode or cathode near the encapsulation layer is transparent or partially transparent within the desired wavelength range, and the optical transmittance of the electrode must be higher than 30%. Besides thin metals and transparent metal oxides, the transparent or partially transparent anode or cathode near the encapsulation layer can be achieved using nanomaterials or nanowires.
[0022] In this embodiment, the method for forming the electrode is not limited. The electrode can be formed, for example, by one or more dry processes selected from solution deposition, sol-gel deposition, vacuum thermal evaporation, atomic layer deposition, chemical vapor deposition, electrodeposition, and anodic oxidation.
[0023] The substrate can be formed of any material. When light is incident from the substrate side, it needs to be formed of a material with high transparency.
[0024] Examples of substrate constituent materials include: inorganic materials such as glass, sapphire, and titanium dioxide; organic materials such as polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, fluoropolymers, vinyl chloride, polyethylene, cellulose, polyvinylidene chloride, aromatic polyamides, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, and polynorbornene; paper materials such as paper and synthetic paper; and composite materials such as materials formed by surface coating or lamination to impart insulation to metals such as stainless steel, titanium, and aluminum. The substrate constituent materials can be used alone or in any combination and ratio of two or more materials.
[0025] The shape and size of the substrate are not limited and can be set arbitrarily. If the substrate is too thin, its strength will be insufficient to meet the function of a support component; if it is too thick, the cost will increase. The substrate is usually a film or plate with a thickness of about 10μm to 50mm.
[0026] The encapsulation layer ensures stable operation of the infrared organic photoelectric sensor under various operating environments and throughout its target lifespan. If the infrared organic photoelectric sensor is bottom-incident, this encapsulation layer does not need to be optically transparent. If the infrared organic photoelectric sensor is top-incident, this encapsulation layer should be transparent in the operating wavelength range, with an optical transmittance of over 30%.
[0027] The encapsulation layer can be formed using various vacuum deposition methods, such as thermal evaporation, molecular beam deposition, plasma sputtering, or atomic layer deposition. It can also be prepared using liquid deposition methods, such as drop coating, dip coating, spin coating, and various printing methods. Besides using a single material, the encapsulation layer can also be formed using alternating multilayer films. In addition to improving encapsulation performance, this alternating film structure can also be used to optimize the optical resonant cavity structure of infrared organic photoelectric sensors in the operating wavelength band, thereby optimizing their photosensitiveness and specific detectivity.
[0028] Commonly used inorganic encapsulation materials include silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, zirconium oxide, magnesium oxide, zirconium oxide, and magnesium fluoride. Commonly used organic encapsulation materials include polymethyl methacrylate, polyethylene oxide, polystyrene, polyvinylpyrrolidone, polycarbonate, polyacrylic acid, epoxy resin, parylene, and polysiloxane.
[0029] The photosensitive layer comprises an organic semiconductor in the form of a single-phase film or a D / A bulk heterojunction blend film, an inorganic semiconductor or compound semiconductor in the form of single-phase or quantum dot nanoparticles, or a combination thereof in a mixed form or a stacked thin film form; wherein, D represents an organic donor material of electron donor; and A represents an organic acceptor material of electron acceptor;
[0030] The inorganic semiconductors include Si, Ge, SiGe, and CuInS in crystalline or polycrystalline forms. x Se 2-x (0≤x≤2), CuInGa(S,Se), PbS, PbI2, PBI3, InGaAs nanoquantum dots, nanoquantum films or single-phase films;
[0031] The organic semiconductor comprises an organic blend of D / A consisting of one or more organic donor materials used as electron donors (D) and one or more organic acceptor materials used as electron acceptors (A).
[0032] The photosensitive layer can detect light in the wavelength range of 750nm to 2000nm.
[0033] The organic donor material may be one or more of the following:
[0034]
[0035]
[0036] The organic acceptor material may be one or more of the following:
[0037]
[0038]
[0039] Preferably, the electron transport layer comprises a plurality of electron transport sublayers stacked together; the electron mobility of the plurality of electron transport sublayers gradually increases along the direction from the photosensitive layer to the cathode; the electron mobility of the electron transport layer is the overall mobility measured by the plurality of electron transport sublayers.
[0040] The electron mobility of the multilayered electron transport sublayer gradually increases from the photosensitive layer toward the cathode, which reduces the loss during electron transport, increases the electron transport rate, and improves the efficiency of electron transport to the cathode.
[0041] The electron transport layer of this invention has at least one electron transport sublayer, which can improve photoelectric conversion efficiency and reduce dark current. Furthermore, the LUMO difference between the acceptor material of the electron transport sublayer and the photosensitive layer is preferably below 1.5 eV, and more preferably 1.0 eV.
[0042] Furthermore, the electron mobility of the electron transport sublayer near the photosensitive layer is greater than the electron mobility of the acceptor material in the photosensitive layer.
[0043] The material of the electron transport sublayer includes organic compound 1, inorganic compound 1, or a combination thereof;
[0044] Wherein, the organic compound 1 includes fullerenes and their derivatives, 4,7-diphenyl-1,10-phenanthroline, polyethyleneimine, polyethoxyethyleneimine, 2,9-dimethyl-4,7-biphenyl-1,10-o-diazaphenanthroline, [9,9-dioctylfluorene-9,9-bis(N,N-dimethylaminopropyl)fluorene], brominated-[9,9-dioctylfluorene-9,9-bis(N,N-dimethylaminopropyl)fluorene], lithium 8-hydroxyquinoline, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, bis(2-methyl-8-quinoline)-4-(phenylphenol)aluminum, 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, naphthalimide bromide, or a mixture or complex of the above materials;
[0045] The inorganic compound 1 includes zinc oxide, tin oxide, aluminum-doped zinc oxide, magnesium-doped zinc oxide, gallium-doped zinc oxide, titanium oxide, tantalum oxide, zinc sulfide, chromium sulfide, or a mixture or composite of the above materials.
[0046] Preferably, the electron transport sublayer can be formed by wet film deposition or vacuum evaporation, but vacuum evaporation is usually used.
[0047] The thickness of the electron transport sublayer ranges from 5 nm to 200 nm.
[0048] Changes in the thickness of the electron transport layer not only affect the charge transport of the device, but also its impedance characteristics, thereby influencing the magnitude of the photocurrent and dark current.
[0049] Preferably, the hole transport layer comprises a plurality of stacked hole transport sublayers; the hole mobility of the plurality of hole transport sublayers gradually increases along the direction from the photosensitive layer toward the anode; the hole mobility of the hole transport layer is the hole mobility measured as a whole of the plurality of hole transport sublayers.
[0050] The hole mobility of the multi-layered hole transport sublayer gradually increases from the photosensitive layer towards the anode, reducing losses during hole transport, increasing the hole transport rate, and improving the efficiency of hole transport to the anode. The hole transport layer includes at least one hole transport sublayer.
[0051] Furthermore, the hole mobility of the hole transport sublayer near the photosensitive layer is greater than the hole mobility of the donor material in the photosensitive layer.
[0052] Furthermore, the material of the hole transport sublayer includes organic compound 2, inorganic compound 2, or a combination thereof;
[0053] The organic compound 2 includes 4,4'-cyclohexylbis[N,N'-di(4-methylphenyl)aniline], N,N'-bis(naphthyl-1-yl)-N,N'-bis(phenyl)-benzidine, N,N'-bis(naphthyl-1-yl)-N,N'-bis(phenyl)-2,7-diamino9,9-spirodifluorene, 2,2',7,7'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, 4,4',4"-tris(carbazole-9-yl)triphenylamine, poly(4-butyltriphenylamine), polyvinylcarbazole, and polystyrene-N,N'-diphenyl-N,N'-bis-(3-methylphenyl)-(1,1)-biphenyl-4,4 One or more of the following: '-diamine perfluorocyclobutane, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), and poly[bis(4-phenyl)(4-butylphenyl)amine];
[0054] The inorganic compound 2 includes tungsten oxide, molybdenum oxide, vanadium oxide, chromium oxide, nickel oxide, copper oxide, cuprous oxide, cuprous thiocyanate, copper sulfide, copper iodide, copper phthalocyanine, or a mixture or complex of the above materials.
[0055] The electron transport sublayer and hole transport sublayer are prepared independently from one or more of the following methods: solution film formation, sol-gel film formation, vacuum thermal evaporation, atomic layer deposition, chemical vapor deposition, electrodeposition, and anodic oxidation.
[0056] The thickness of the hole transport sublayer ranges from 5nm to 200nm.
[0057] The electron mobility of the electron transport layer ranges from 1 to 10. ~ The range of the hole mobility is: ~ .
[0058] The hole mobility of the hole transport layer described in this invention can be comprehensively controlled by adjusting the thickness of the hole transport layer and the selected material. Similarly, the electron mobility of the electron transport layer can be comprehensively controlled by adjusting the thickness of the electron transport layer and the selected material, so that the relationship between the hole mobility of the hole transport layer and the electron mobility of the electron transport layer satisfies the above-mentioned relationship. Preferably, the relationship between the hole mobility of the hole transport layer and the electron mobility of the electron transport layer satisfies the following:
[0059] 0.02≤μ h / μ e ≤50
[0060] Where, μ h μ represents the hole mobility of the hole transport layer. e This represents the electron mobility of the electron transport layer.
[0061] In this invention, the thickness of the carrier transport layer (i.e., the electron transport layer and hole transport layer) is positively correlated with the carrier mobility of the carrier transport layer. Since a thicker carrier transport layer results in a longer carrier transport path, a higher electron mobility is required to complete the journey within the same timeframe. Therefore, a thicker carrier transport layer necessitates a higher required carrier mobility. Similarly, the thickness of the hole transport layer is also positively correlated with the hole mobility of the hole transport layer.
[0062] Generally, the thickness of both the electron transport layer and the hole transport layer is less than the thickness of the photosensitive layer.
[0063] Generally, the optical band gaps of both the electron transport layer and the hole transport layer are greater than the lowest optical band gap of the photosensitive layer, preferably greater than 0.3 eV; the effective Fermi levels of the electron transport layer and the hole transport layer correspond to the energy levels of the corresponding charges in the photosensitive layer; for the electron transport layer, the energy difference between its effective Fermi level and the LUMO (lowest unoccupied molecular orbital in organic electronics) of the photosensitive layer is greater than -0.15 eV; for the hole transport layer, the energy difference between its effective Fermi level and the HOMO (highest occupied molecular orbital in organic electronics) of the photosensitive layer is less than +0.15 eV. This energy difference condition satisfies the effective transport of the corresponding charges at room temperature; the mobility of the electron transport layer and the hole transport layer in transporting the corresponding charges is greater than the mobility of the corresponding charges in the photosensitive layer, so that the voltage drop across the photosensitive layer under operating conditions is much greater than the voltage drop across the electron transport layer or the hole transport layer. Here, the charge is either an electron or a hole.
[0064] An infrared organic photoelectric sensor array, the infrared organic photoelectric sensor array comprising a plurality of pixels, the pixels comprising the infrared organic photoelectric sensor.
[0065] Preferably, the infrared organic photoelectric sensor further includes a substrate; the substrate is a pixel readout circuit composed of silicon-based complementary metal-oxide-semiconductor transistors or thin-film transistors.
[0066] An infrared organic photoelectric sensor chip, comprising the aforementioned infrared organic photoelectric sensor array.
[0067] Compared with the prior art, the beneficial effects of the present invention are:
[0068] This invention regulates the relationship between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, ensuring that the difference between their mobilities remains within a reasonable range. This guarantees and balances carrier transport, extraction, and collection within the device, thereby improving the sensitivity of the infrared organic sensor and the imaging clarity and resolution of its focal plane array. It effectively avoids the problem of reduced sensitivity in the infrared organic photoelectric sensor, or even the inability of the readout circuit in the focal plane array to effectively acquire the corresponding signal, due to an excessive difference in the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, thus affecting the imaging clarity and resolution of the focal plane array. Attached Figure Description
[0069] Figure 1 is a schematic diagram of the structure of an infrared organic photoelectric sensor provided by the present invention.
[0070] Figure 2 is a schematic diagram of the EQE of the infrared organic photoelectric sensor in Examples 1 and 2.
[0071] Figure 3 is a schematic diagram of the dark current of the infrared organic photoelectric sensor in Examples 1 and 2.
[0072] Figure 4 is a schematic diagram of the responsivity of the infrared organic photoelectric sensors in Examples 1 and 2.
[0073] Figure 5 is a schematic diagram of the specific detectivity of the infrared organic photoelectric sensors in Examples 1 and 2.
[0074] Figure 6 is a schematic diagram of the EQE of the infrared organic photoelectric sensor in Examples 3 and 4.
[0075] Figure 7 is a schematic diagram of the dark current of the infrared organic photoelectric sensor in Examples 3 and 4.
[0076] Figure 8 is a schematic diagram of the responsivity of the infrared organic photoelectric sensors in Examples 3 and 4.
[0077] Figure 9 is a schematic diagram of the specific detectivity of the infrared organic photoelectric sensors in Examples 3 and 4.
[0078] Figure 10 is a schematic diagram of the EQE of the infrared organic photoelectric sensor in Examples 5 and 6.
[0079] Figure 11 is a schematic diagram of the dark current of the infrared organic photoelectric sensor in Examples 5 and 6.
[0080] Figure 12 is a schematic diagram of the responsivity of the infrared organic photoelectric sensors in Examples 5 and 6.
[0081] Figure 13 is a schematic diagram of the specific detectivity of the infrared organic photoelectric sensors in Examples 5 and 6.
[0082] Figure 14 is a cross-sectional view of an infrared organic photoelectric sensor array provided in Example 7.
[0083] Figure 15 is a top view of an infrared organic photoelectric sensor array provided in Example 7.
[0084] Figure 16 is an example of imaging using the infrared organic photoelectric sensor array of Example 1.
[0085] Figure 17 is an example of imaging using the infrared organic photoelectric sensor array of Example 2.
[0086] In the figure: 1-cathode, 2-electron transport layer, 3-photosensitive layer, 4-hole transport layer, 5-anode, 6-pixel, 7-encapsulation layer, 8-pixel readout circuit, 9-substrate, 10-infrared organic photoelectric sensor array. Detailed Implementation
[0087] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0088] It should be understood that, when used in this specification, the terms “comprising” and “including” indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.
[0089] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms.
[0090] It should also be further understood that the term "and / or" as used in this specification refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.
[0091] Example 1
[0092] This embodiment provides an infrared organic photoelectric sensor for photosensitizing, as shown in Figure 1. The sensor includes a cathode, an electron transport layer, a photosensitive layer, a hole transport layer, and an anode stacked sequentially.
[0093] The cathode is made of indium tin oxide (ITO); the electron transport layer is made of zinc oxide (ZnO); the hole transport layer is made of copper phthalocyanine (CuPc); the anode is made of metallic silver; the photosensitive layer 3 adopts a bulk heterojunction structure, which is composed of a blend of one electron donor and two electron acceptors; the preferred electron donor material is NT812, and the electron acceptor materials are organic molecules D1 and BTR. Furthermore, the mass ratio of NT812 to D1 and BTR is 1:1:0.5. D1 is: 2,2'-((12,13-bis(2-butyloctyl)-3,9-docodialkyl-12,13-dihydro-[1,2,5]thiadiazo[3,4-e]thieno[2'', 3'': 4', 5']thieno[2', 3': 4,5]pyrrolo[3,2-g]thieno[2', 3': 4,5]thieno[3,2-b]indol-2,10-diyl)bis(6,7-difluoro-4-oxonaphth-3(4H)-yl-1(4H)-ylidene))dicarboxylonite. It is disclosed in the patent "A short-wave infrared responsive deuterated quinone-terminated N-type organic molecule and its preparation method and application, Publication No.: CN118290445A".
[0094] The fabrication process of the infrared organic photoelectric sensor is as follows:
[0095] The ITO conductive substrate was ultrasonically treated and cleaned sequentially with isopropanol, detergent, deionized water, and acetone, with each treatment lasting 20 minutes. The cleaned ITO conductive substrate was then dried in a 60°C oven for 5 hours; finally, the ITO conductive substrate underwent plasma surface treatment.
[0096] 50 nm ZnO was prepared by magnetron sputtering with a sputtering power of 100 W and a cavity pressure of 5 mtorr.
[0097] The donor material NT812, the acceptor material D1, and BTR were blended at the above mass ratio and added to a mixed solvent of chlorobenzene and 1-chloronaphthalene (98:2, v / v) to make the concentration of NT812 10 mg / ml.
[0098] The mixture was stirred thoroughly at 65°C for 4 hours, then spin-coated onto the zinc oxide film at 800 rpm for 1 minute, and then heat-annealed at 100°C for 10 minutes to obtain a photosensitive layer film of the specified thickness.
[0099] In 5×10 -7 Under the vacuum conditions of torr, a 20 nm thick CuPC was deposited on the above photosensitive layer by vacuum evaporation at a deposition rate of 0.1 Å / s.
[0100] In 5×10 -7 Under vacuum conditions, a silver film of a specified thickness is thermally deposited on the aforementioned CuPc film as an anode, thereby obtaining an infrared organic photoelectric sensor.
[0101] The mobilities of the ZnO electron transport layer and CuPc hole transport layer prepared by the above method were tested using a Hall effect meter; among them, the measured mobility μ of the electron transport layer was... e =0.47 cm² / (V·s), hole transport layer mobility μ h =1.47E-3 cm² / (V·s), μ h / μ e =0.003.
[0102] Example 2
[0103] The difference between Example 2 and Example 1 is that the preparation process of the electron transport layer ZnO was changed, while the rest is the same as Example 1.
[0104] Preparation of zinc oxide: 40 nm ZnO was prepared by sol-gel method. 0.4 g of dihydrate and zinc acetate were dissolved in 4 mL of 2-methoxyethanol and 110 μL of ethanolamine mixed solvent and stirred overnight to obtain ZnO precursor solution. The ZnO solution was then spin-coated onto ITO substrate and then heated and annealed to obtain a 40 nm thick ZnO film.
[0105] The mobility of the ZnO electron transport layer and CuPc hole transport layer prepared by the above method was tested using a Hall effect meter. Specifically, the measured mobility μ of the electron transport layer was... e =1.98E-3 cm² / (V·s), hole transport layer mobility μ h =1.47E-3 cm² / (V·s), μ h / μ e =0.742.
[0106] The EQE, dark current, responsivity, and specific detectivity of the infrared organic photoelectric sensors of Examples 1 and 2 are measured, as shown in Figures 2, 3, 4, and 5. Based on the measured EQE, dark current, responsivity, and specific detectivity, it can be seen that the closer the electron mobility of the electron transport layer is to the hole mobility of the hole transport layer, the higher the specific detectivity of the infrared organic photoelectric sensor, the lower the corresponding dark current, and the higher its sensitivity. Conversely, the greater the difference between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, the lower the specific detectivity of the infrared organic photoelectric sensor, the higher the corresponding dark current, and the lower its sensitivity.
[0107] Example 3
[0108] This embodiment provides an infrared organic photoelectric sensor for photosensitizing, as shown in Figure 1. The sensor includes an anode, a hole transport layer, a photosensitive layer, an electron transport layer, and a cathode stacked sequentially.
[0109] The anode is indium tin oxide (ITO); the hole transport layer is copper iodide (CuI); the electron transport layer is fullerene (C60); the cathode is metallic silver; and the photosensitive layer 3 adopts a bulk heterojunction structure, composed of a blend of one electron donor and two electron acceptors. The preferred electron donor material is NT812, and the electron acceptor materials are the organic molecules D1 and BTR. Furthermore, the mass ratio of NT812 to D1 and BTR is 1:1:0.5. D1 is: 2,2'-((12,13-bis(2-butyloctyl)-3,9-docodialkyl-12,13-dihydro-[1,2,5]thiadiazo[3,4-e]thieno[2'', 3'': 4', 5']thieno[2', 3': 4,5]pyrrolo[3,2-g]thieno[2', 3': 4,5]thieno[3,2-b]indol-2,10-diyl)bis(6,7-difluoro-4-oxonaphth-3(4H)-yl-1(4H)-ylidene))dicarboxylonite. It is disclosed in the patent "A short-wave infrared responsive deuterated quinone-terminated N-type organic molecule and its preparation method and application, Publication No.: CN118290445A".
[0110] The above-mentioned method for fabricating an infrared organic photoelectric sensor includes the following steps:
[0111] The ITO conductive substrate was ultrasonically treated and cleaned sequentially with isopropanol, detergent, deionized water, and acetone, with each treatment lasting 20 minutes. The cleaned ITO conductive substrate was then dried in a 60°C oven for 5 hours; finally, the ITO conductive substrate underwent plasma surface treatment.
[0112] In 5×10 -7 Under the vacuum conditions of torr, 10 nm of CuI was deposited on the above ITO substrate by vacuum evaporation at a deposition rate of 0.1 Å / s.
[0113] The donor material NT812, the acceptor material D1, and BTR were blended at the above mass ratio and added to a mixed solvent of chlorobenzene and 1-chloronaphthalene (98:2, v / v) to make the concentration of NT812 10 mg / ml.
[0114] The mixture was stirred thoroughly at 65°C for 4 hours, then spin-coated onto the zinc oxide film at 800 rpm for 1 minute, and then heat-annealed at 100°C for 10 minutes to obtain a photosensitive layer film of the specified thickness.
[0115] In 5×10 -7 Under the vacuum conditions of torr, 30 nm of C60 was deposited on the above photosensitive layer by vacuum evaporation at a deposition rate of 0.1 Å / s.
[0116] In 5×10 -7 Under vacuum conditions, a silver film of a specified thickness is thermally deposited on the aforementioned fullerene film as a cathode, thereby obtaining an infrared organic photoelectric sensor.
[0117] The mobilities of the fullerene electron transport layer and the CuI hole transport layer prepared by the above method were tested using a Hall effect meter. The measured mobility μ of the electron transport layer was... e =3.31E-2 cm² / (V·s), hole transport layer mobility μ h =10.17cm² / (V·s), μ h / μ e =307.25.
[0118] Example 4
[0119] The difference between Example 4 and Example 3 is as follows:
[0120] Magnesium-doped fullerene C60 was used as an electron transport layer to form a magnesium and fullerene C60 blend layer. The doping ratio was controlled by the evaporation rate, with the preferred evaporation rate being fullerene C60:Mg = 2:1. Other preparation methods were the same as in Example 3.
[0121] Preparation of electron transport layer: A 30 nm Mg and C60 blend layer was prepared by vacuum evaporation, with Mg deposition rate of 0.05 Å / s and C60 deposition rate of 0.1 Å / s.
[0122] The mobilities of the magnesium-doped fullerene electron transport layer and the CuI hole transport layer prepared by the above method were measured using a Hall effect meter. Specifically, the measured mobility μ of the electron transport layer was... e = 0.114 cm² / (V·s), Hole transport layer mobility μ h =10.17cm² / (V·s), μ h / μ e =89.21.
[0123] The EQE, dark current, responsivity, and specific detectivity of the infrared organic photoelectric sensors of Examples 3 and 4 are measured, as shown in Figures 6, 7, 8, and 9. Based on the measured EQE, dark current, responsivity, and specific detectivity, it can be seen that the closer the electron mobility of the electron transport layer is to the hole mobility of the hole transport layer, the higher the specific detectivity of the infrared organic photoelectric sensor, the lower the corresponding dark current, and the higher its sensitivity. Conversely, the greater the difference between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, the lower the specific detectivity of the infrared organic photoelectric sensor, the higher the corresponding dark current, and the lower its sensitivity.
[0124] Example 5
[0125] This embodiment provides an infrared organic photoelectric sensor, as shown in Figure 1, which includes an anode, a hole transport layer, a photosensitive layer, an electron transport layer, and a cathode stacked sequentially.
[0126] The anode is indium tin oxide (ITO); the hole transport layer is poly[bis(4-phenyl)(4-butylphenyl)amine] (Poly-TPD); the electron transport layer is naphthalimide bromide (NDI-Br); and the cathode is metallic silver. The photosensitive layer 3 adopts a bulk heterojunction structure, composed of a blend of one electron donor and two electron acceptors. The preferred electron donor material is NT812, and the electron acceptor materials are the organic molecules D1 and BTR. Furthermore, the mass ratio of NT812 to D1 and BTR is 1:1:0.5. D1 is: 2,2'-((12,13-bis(2-butyloctyl)-3,9-docodialkyl-12,13-dihydro-[1,2,5]thiadiazo[3,4-e]thieno[2'', 3'': 4', 5']thieno[2', 3': 4,5]pyrrolo[3,2-g]thieno[2', 3': 4,5]thieno[3,2-b]indol-2,10-diyl)bis(6,7-difluoro-4-oxonaphth-3(4H)-yl-1(4H)-ylidene))dicarboxylonite. It is disclosed in the patent "A short-wave infrared responsive deuterated quinone-terminated N-type organic molecule and its preparation method and application, Publication No.: CN118290445A".
[0127] The above-mentioned method for fabricating an infrared organic photoelectric sensor includes the following steps:
[0128] The ITO conductive substrate was ultrasonically treated and cleaned sequentially with isopropanol, detergent, deionized water, and acetone, with each treatment lasting 20 minutes. The cleaned ITO conductive substrate was then dried in a 60°C oven for 5 hours; finally, the ITO conductive substrate underwent plasma surface treatment.
[0129] A 15 nm Poly-TPD was prepared by spin coating followed by drying. During the preparation of Poly-TPD, 10% by mass of the photocrosslinking agent bisPFPA was added to the Poly-TPD solution. After spin coating and drying, the Poly-TPD film was cured with a UV lamp to prevent solvents from dissolving the Poly-TPD in subsequent preparation processes.
[0130] The donor material NT812, the acceptor material D1, and BTR were blended at the above mass ratio and added to a mixed solvent of chlorobenzene and 1-chloronaphthalene (98:2, v / v) to make the concentration of NT812 10 mg / ml.
[0131] The mixture was stirred thoroughly at 65°C for 4 hours, then spin-coated onto the zinc oxide film at 800 rpm for 1 minute, and then heat-annealed at 100°C for 10 minutes to obtain a photosensitive layer film of the specified thickness.
[0132] 10 nm NDI-Br was prepared by spin coating followed by drying.
[0133] In 5×10 -7 Under vacuum conditions, a silver film of a specified thickness is thermally deposited on the aforementioned electron transport layer film as a cathode, thereby obtaining an infrared organic photoelectric sensor.
[0134] The mobilities of the NDI-Br electron transport layer and the Poly-TPD hole transport layer prepared by the above method were tested using a Hall effect meter; among them, the measured mobility μ of the electron transport layer was... e = 2.6E-4cm² / (V·s), Hole transport layer mobility μ h =4.7E-4 cm² / (V·s), μ h / μ e =1.81.
[0135] Example 6
[0136] The difference between Example 6 and Example 5 is that poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS) is used as the hole transport layer. Other preparation methods are the same as in Example 5.
[0137] The hole transport layer was prepared by spin-coating and drying to create a 30nm PEDOT:PSS layer.
[0138] The mobilities of the NDI-Br electron transport layer and the PEDOT:PSS hole transport layer prepared by the above method were tested using a Hall effect meter; among them, the measured mobility μ of the electron transport layer was... e=2.6E-4 cm² / (V·s), hole transport layer mobility μ h =0.076 cm² / (V·s), μ h / μ e =292.31.
[0139] The EQE, dark current, responsivity, and specific detectivity of the infrared organic photoelectric sensors in Examples 5 and 6 are measured, as shown in Figures 10, 11, 12, and 13. Based on the measured EQE, dark current, responsivity, and specific detectivity, it can be seen that the closer the electron mobility of the electron transport layer is to the hole mobility of the hole transport layer, the higher the specific detectivity of the infrared organic photoelectric sensor, the lower the corresponding dark current, and the higher its sensitivity. Conversely, the greater the difference between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, the lower the specific detectivity of the infrared organic photoelectric sensor, the higher the corresponding dark current, and the lower its sensitivity.
[0140] Example 7
[0141] Based on the infrared organic photoelectric sensor provided in the above embodiments, an infrared organic photoelectric sensor array is also provided, as shown in Figures 14 and 15. The infrared organic photoelectric sensor array 10 includes a plurality of pixels 6, and the pixels 6 include the infrared organic photoelectric sensor as described in any one of embodiments 2, 4, and 5.
[0142] In this embodiment, the infrared organic photoelectric sensor array 10 further includes a substrate 9; the substrate 9 is a pixel readout circuit 8 composed of silicon-based complementary metal-oxide-semiconductor transistors or thin-film transistors.
[0143] As shown in Figure 15, the infrared organic optoelectronic sensor array 10, from bottom to top, includes a pixel readout circuit 9 composed of silicon-based complementary metal-oxide-semiconductor transistors (MOSFETs) fabricated on a single-crystal silicon substrate. Each pixel readout circuit is linked to a bottom electrode (here, cathode 1) array that defines the pixel size. Above the bottom electrode array are the electron transport layer 2, photosensitive layer 3, hole transport layer 4, top electrode (here, anode 5), and encapsulation layer 7. The electron transport layer 2, photosensitive layer 3, hole transport layer 4, top electrode, and encapsulation layer 7 form a continuous structure across the entire array region.
[0144] The infrared organic optoelectronic sensor array described in this embodiment consists of N×M pixels arranged in a grid. The size of pixel 6 is 25μm, and the number of pixels is 1×256 or 1×512. Imaging tests are performed using infrared organic optoelectronic sensor arrays composed of the infrared organic optoelectronic sensors of Embodiments 1 and 2. The imaging of the infrared organic optoelectronic sensor array composed of the infrared organic optoelectronic sensor of Embodiment 1 is shown in Figure 16; the imaging of the infrared organic optoelectronic sensor array composed of the infrared organic optoelectronic sensor of Embodiment 2 is shown in Figure 17. As can be seen from Figures 16 and 17, the difference between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer affects the imaging sharpness and resolution of the focal plane array device. The smaller the difference between the electron mobility of the electron transport layer and the hole mobility of the hole transport layer, the higher the imaging sharpness.
[0145] In one specific embodiment, the electron transport layer 2 in the infrared organic photoelectric sensor array can also be configured as two electron transport sublayers, and the hole transport layer 4 can also be configured as two hole transport sublayers.
[0146] When electron transport layer 2 is configured as a multilayer electron transport sublayer, the various electron transport sublayers can be made of the same material or different materials; for the same material, different fabrication processes can be used to form sublayers with the required mobility. Similarly, the hole transport layer can also be configured in this way.
[0147] Example 8
[0148] This embodiment also provides an infrared organic photoelectric sensor chip, which includes the infrared organic photoelectric sensor array described in Embodiment 7. The infrared organic photoelectric sensor chip is used for infrared photosensitive imaging.
[0149] The infrared organic photoelectric sensor chip described in this embodiment can be applied in the following aspects:
[0150] 1. It can be an industrial camera used to detect and identify defects, foreign objects, cracks, and other problems on the surface of materials.
[0151] 2. It can also be applied to medical diagnosis, as infrared light can penetrate the skin and other biological tissues, providing deeper detail and resolution.
[0152] 3. It can also be applied to food safety, specifically for detecting contaminants, components, and quality in food.
[0153] 4. It can also be applied to environmental monitoring, helping to monitor environmental parameters such as air pollutants, water quality, and soil moisture content.
[0154] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.
Claims
1. An infrared organic photoelectric sensor, the infrared organic photoelectric sensor being used for photosensitive, the sensor comprising a cathode, an electron transport layer, a photosensitive layer, a hole transport layer, and an anode arranged in sequence; Its features are: The electron mobility of the electron transport layer and the hole mobility of the hole transport layer satisfy the following relationship: 0.01≤μ h / m e ≤100; Where, μ h μ represents the hole mobility of the hole transport layer. e This represents the electron mobility of the electron transport layer.
2. The infrared organic photoelectric sensor according to claim 1, characterized in that: The electron transport layer comprises several electron transport sublayers stacked together; the electron mobility of the several electron transport sublayers gradually increases along the direction from the photosensitive layer to the cathode; the electron mobility of the electron transport layer is the overall mobility measured by the combination of the several electron transport sublayers.
3. The infrared organic photoelectric sensor according to claim 2, characterized in that: The electron mobility of the electron transport sublayer near the photosensitive layer is greater than that of the acceptor material in the photosensitive layer.
4. The infrared organic photoelectric sensor according to claim 2, characterized in that: The material of the electron transport sublayer includes organic compound 1, inorganic compound 1, or a combination thereof; Wherein, the organic compound 1 includes fullerenes and their derivatives, 4,7-diphenyl-1,10-phenanthroline, polyethyleneimine, polyethoxyethyleneimine, 2,9-dimethyl-4,7-biphenyl-1,10-o-diazaphenanthroline, [9,9-dioctylfluorene-9,9-bis(N,N-dimethylaminopropyl)fluorene], brominated-[9,9-dioctylfluorene-9,9-bis(N,N-dimethylaminopropyl)fluorene], lithium 8-hydroxyquinoline, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, bis(2-methyl-8-quinoline)-4-(phenylphenol)aluminum, 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, naphthalimide bromide, or a mixture or complex of the above materials; The inorganic compound 1 includes zinc oxide, tin oxide, aluminum-doped zinc oxide, magnesium-doped zinc oxide, gallium-doped zinc oxide, titanium oxide, tantalum oxide, zinc sulfide, chromium sulfide, or a mixture or composite of the above materials.
5. The infrared organic photoelectric sensor according to claim 2, characterized in that: The thickness of the electron transport sublayer ranges from 5 to 200 nm.
6. The infrared organic photoelectric sensor according to claim 1, characterized in that: The hole transport layer comprises several stacked hole transport sublayers; the hole mobility of the several hole transport sublayers gradually increases along the direction from the photosensitive layer to the anode; the hole mobility of the hole transport layer is the hole mobility measured as a whole composed of the several hole transport sublayers.
7. The infrared organic photoelectric sensor according to claim 6, characterized in that: The hole mobility of the hole transport sublayer near the photosensitive layer is greater than that of the hole mobility of the donor material in the photosensitive layer.
8. The infrared organic photoelectric sensor according to claim 6, characterized in that: The material of the hole transport sublayer includes organic compound 2, inorganic compound 2, or a combination thereof; The organic compound 2 includes 4,4'-cyclohexylbis[N,N'-di(4-methylphenyl)aniline], N,N'-bis(naphthyl-1-yl)-N,N'-bis(phenyl)-benzidine, N,N'-bis(naphthyl-1-yl)-N,N'-bis(phenyl)-2,7-diamino9,9-spirodifluorene, 2,2',7,7'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, 4,4',4"-tris(carbazole-9-yl)triphenylamine, poly(4-butyltriphenylamine), polyvinylcarbazole, and polystyrene-N,N'-diphenyl-N,N'-bis-(3-methylphenyl)-(1,1)-biphenyl-4,4 One or more of the following: '-diamine perfluorocyclobutane, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid), and poly[bis(4-phenyl)(4-butylphenyl)amine]; The inorganic compound 2 includes tungsten oxide, molybdenum oxide, vanadium oxide, chromium oxide, nickel oxide, copper oxide, cuprous oxide, cuprous thiocyanate, copper sulfide, copper iodide, copper phthalocyanine, or a mixture or complex of the above materials.
9. The infrared organic photoelectric sensor according to claim 6, characterized in that: The thickness of the hole transport sublayer ranges from 5 nm to 200 nm.
10. The infrared organic photoelectric sensor according to claim 1, characterized in that: The electron mobility of the electron transport layer ranges from 1 to 10. ~ The range of the hole mobility is: ~ .
11. An infrared organic photoelectric sensor array, characterized in that: The infrared organic photoelectric sensor array includes a plurality of pixels, and the pixels include the infrared organic photoelectric sensor as described in claim 1.
12. The infrared organic photoelectric sensor array according to claim 11, characterized in that: The infrared organic photoelectric sensor also includes a substrate; the substrate is a pixel readout circuit composed of silicon-based complementary metal-oxide-semiconductor transistors or thin-film transistors.
13. An infrared organic photoelectric sensor chip, characterized in that: Including the infrared organic photoelectric sensor array as described in claim 11.