Organic photodetector, method of making the same, and device comprising the organic photodetector

Abstract

The application relates to an organic photodetector, a device comprising the organic photodetector and a method for preparing the organic photodetector. The organic photodetector comprises a spectral absorption layer, a first electrode, a second electrode and an organic active layer arranged between the first electrode and the second electrode; wherein the spectral absorption range of the spectral absorption layer and the spectral absorption range of the organic active layer partially overlap, and the organic photodetector can realize selective high-sensitivity detection of any required different waveband narrowband light in a full-spectrum range of visible light-near infrared light.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optoelectronics, in particular to the technical field of organic photodetectors, and specifically relates to an organic photodetector, a preparation method thereof and an apparatus comprising the organic photodetector. BACKGROUND

[0002] A photodetector can convert a light signal into an electric signal to realize detection of the wavelength and intensity of light, and is widely used in the fields of military affairs, aerospace, biological medicine, image sensing, etc. Selective detection of light such as single-band light or monochromatic light, and reduction of the interference of ambient light have strategic and economic significance in the fields of optical communication, medical detection, biological identification, missile guidance, satellite remote sensing detection, etc. Although the narrow-band organic photodetectors reported in the literature can realize detection of a certain narrow-band light to some extent, it is difficult to realize detection of any narrow-band light in the full waveband range of visible-near infrared light, and such devices are not universal. At the same time, such narrow-band photodetectors need high-voltage driving to improve their responsivity and reduce the half-peak width, resulting in high energy consumption of the devices. Since the film of such devices is relatively thick, the mobility of holes and electrons in the active layer differs greatly, resulting in the retention of low-mobility carriers in the active layer, which is difficult to flow to the electrode quickly, so such narrow-band photodetectors generally have slow response speed and are difficult to realize high-speed detection of narrow-band light, which greatly limits their application in the fields of communication, sensing, high-speed imaging, security systems, etc. SUMMARY

[0003] In one aspect, the present application provides an organic photodetector, comprising:

[0004] a spectral absorption layer;

[0005] a first electrode;

[0006] a second electrode; and

[0007] an organic active layer disposed between the first electrode and the second electrode;

[0008] wherein the spectral absorption range of the spectral absorption layer and the spectral absorption range of the organic active layer partially overlap.

[0009] In another aspect, the present application provides an apparatus comprising the above-mentioned organic photodetector.

[0010] In yet another aspect, the present application provides a preparation method of an organic photodetector, comprising:

[0011] providing a first electrode;

[0012] providing a second electrode; and

[0013] An organic active layer is disposed between the first electrode and the second electrode; and

[0014] The spectral absorption layer is provided such that a spectral absorption range of the spectral absorption layer partially overlaps with a spectral absorption range of the organic active layer. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A schematic diagram of a narrow-band photodetector device structure according to an embodiment 1 of the present disclosure.

[0016] Figure 2 An external quantum efficiency spectral curve of a narrow-band organic photodetector according to the present disclosure based on D18:PCBM as the active layer in embodiment 1 at 0 bias voltage for a 600 nm peak spectrum.

[0017] Figure 3 An external quantum efficiency spectral curve of a narrow-band organic photodetector according to the present disclosure based on PM6 and F-2F as the active layer in embodiment 2 at 0 bias voltage for a 705 nm peak spectrum.

[0018] Figure 4 An external quantum efficiency spectral curve of a narrow-band organic photodetector according to the present disclosure based on PM6 and FO-2F as the active layer in embodiment 3 at 0 bias voltage for a 800 nm peak spectrum.

[0019] Figure 5 and Figure 6 An external quantum efficiency spectral curve of a narrow-band organic photodetector according to the present disclosure based on PM6 and CH17 as the active layer in embodiment 4 at 0 bias voltage for a 850 nm peak spectrum. DETAILED DESCRIPTION

[0020] DEFINITIONS

[0021] The following definitions and methods are provided to better define the present application and to guide those of ordinary skill in the art in the practice of the present application. Unless otherwise noted, terms are to be understood according to conventional usage by those of ordinary skill in the relevant art. All patents, publications and other publications cited herein are incorporated by reference in their entirety.

[0022] As used herein, the terms “comprises” and “comprising” are to be interpreted as including the stated features, materials, steps or components, but not excluding other features, materials, steps or components. Specifically, the terms “comprises” and “comprising” are to be interpreted as including the stated features, materials, steps or components, but not excluding other features, materials, steps or components.

[0023] As used herein, the term "optional" or "optionally" means that the subsequently described event or circumstance can or can not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0024] Spatially relative terms, such as "under", "below", "lower", "over", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms can be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other elements or features would then be oriented "below" or "under" the other elements or features. Thus, the example term "above" can encompass both an orientation that is above and then below. Moreover, the device can be otherwise oriented (for example, rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0025] When an element such as a layer, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements can be present. In contrast, when an element such as a layer, region, or substrate is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. It will be understood that, when a layer is referred to as being "formed on" another layer, it has been formed directly on the other layer, unless otherwise indicated. Similarly, when an element such as a layer, region, or substrate is referred to as being "between" two other elements, it can be directly between the two other elements or intervening elements can also be present. In addition, it will be understood that when an element is referred to as being "formed on" or "formed over" another element, it can be formed directly on or over the other element or intervening elements can also be present.

[0026] The term "forward device" refers to a device in which the top electrode is in direct contact with the electron transport layer and the bottom electrode is in direct contact with the hole transport layer. The term "reverse device" refers to a device in which the top electrode is in direct contact with the hole transport layer and the bottom electrode is in direct contact with the electron transport layer.

[0027] Where a range of values is given in this document, the range is inclusive of the endpoints, and there are all individual integers and fractions within the range, and also each narrower range formed by the combination of any of the endpoints with the interior integers and fractions, to the same extent as if each of the narrower ranges was, independently, explicitly stated in the document. For example, a half-peak width of a detection peak of an organic photodetector of less than 150 nm means that the half-peak width can be (e.g., 140 nm, 130 nm, 120 nm, 110 nm, 100 nm, 90 nm, 80 nm, 70 nm, 65 nm, 60 nm, 55 nm, 50 nm, etc.).

[0028] In one aspect, the present application provides an organic photodetector, comprising:

[0029] a spectral absorption layer;

[0030] a first electrode;

[0031] a second electrode; and

[0032] an organic active layer disposed between the first electrode and the second electrode;

[0033] wherein a spectral absorption range of the spectral absorption layer and a spectral absorption range of the organic active layer partially overlap.

[0034] In some embodiments, the spectral absorption layer is positioned such that incident light travels through the spectral absorption layer first relative to the organic active layer.

[0035] In some embodiments, the portion of the spectral absorption range of the spectral absorption layer and the spectral absorption range of the organic active layer that do not overlap comprises a spectral response range of the organic photodetector.

[0036] In some embodiments, the non-overlapping portion has a half-peak width of no more than 150 nm (e.g., no more than 140 nm, no more than 130 nm, no more than 120 nm, no more than 110 nm, no more than 100 nm, no more than 90 nm, no more than 80 nm, no more than 70 nm, no more than 65 nm, no more than 60 nm, no more than 55 nm, no more than 50 nm, etc.), no more than 100 nm, or even no more than 80 nm.

[0037] In some embodiments, the organic photodetector has a full width at half maximum of a detection peak of no more than 150 nm (e.g., no more than 140 nm, no more than 130 nm, no more than 120 nm, no more than 110 nm, no more than 100 nm, no more than 90 nm, no more than 80 nm, no more than 70 nm, no more than 65 nm, no more than 60 nm, no more than 55 nm, no more than 50 nm, etc.), no more than 100 nm, or even no more than 80 nm.

[0038] In some embodiments, the organic active layer comprises an electron donor material and an electron acceptor material. In some embodiments, the mass ratio of the electron donor material to the electron acceptor material is 1 :0.5-1 :10 (e.g., 1 :0.5, 1 :0.8, 1 :1, 1 :1.5, 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, 1 :7, 1 :8, 1 :9, or 1 :10, etc.), or 1 :0.5-1 :5.

[0039] In some embodiments, the spectral absorption layer comprises a material that has an absorption spectrum that is the same as or similar to that of an active material species (i.e., active material component type) comprised in the organic active layer.

[0040] In some embodiments, the material comprised in the spectral absorption layer includes, but is not limited to, a combination of one or more of a polymer, an organic small molecule, an oligomer, an inorganic material.

[0041] In some embodiments, the spectral absorption layer comprises a material that is the same as or different from an active material species (i.e., active material component type) comprised in the organic active layer.

[0042] In some embodiments, the spectral absorption layer comprises a spectral absorption material that has an absorption spectrum that is the same as or similar to that of an active material species comprised in the organic active layer;

[0043] wherein:

[0044] the spectral absorption layer comprises a spectral absorption material that is the same as or different from an active material species comprised in the organic active layer; or

[0045] the spectral absorption layer comprises a spectral absorption material that is partially the same as an active material species comprised in the organic active layer; or

[0046] the spectral absorption layer comprises a spectral absorption material that is entirely the same as an active material species comprised in the organic active layer; or

[0047] the spectral absorption layer comprises a spectral absorption material that is not the same as an active material species comprised in the organic active layer.

[0048] In some embodiments, the active material species in the organic active layer and the spectral absorption material species in the spectral absorption layer are partially the same. For example, the active material species in the organic active layer is PM6 and F-2F, and the spectral absorption material species in the spectral absorption layer is PM6; or for example, the active material species in the organic active layer is PM6 and FO-2F, and the spectral absorption material species in the spectral absorption layer is PM6 and F-2F; or for example, the active material species in the organic active layer is D18 and PCBM, and the spectral absorption material species in the spectral absorption layer is D18 and F(Br)-ThCl.

[0049] In some embodiments, the active material species in the organic active layer and the spectral absorption material species in the spectral absorption layer are completely the same. For example, the spectral absorption material in the spectral absorption layer is PM6 and CH17, and the active material species in the organic active layer is PM6 and CH17.

[0050] In some embodiments, the spectral absorption range of the spectral absorption layer is partially overlapped with the spectral absorption range of the organic active layer by regulating and / or selecting one or more of the following items of the photodetector:

[0051] Item 1: the species of the material in the spectral absorption layer and / or the organic active layer;

[0052] Item 2: the ratio of the material in the spectral absorption layer and / or the organic active layer;

[0053] Item 3: the concentration of the material in the solution containing the material for forming the spectral absorption layer and / or the organic active layer;

[0054] Item 4: the thickness of the spectral absorption layer and / or the organic active layer.

[0055] It can be understood that in the above-mentioned items 1 to 4, the material in the spectral absorption layer and / or the organic active layer respectively refers to the spectral absorption material in the spectral absorption layer and the active material in the organic active layer.

[0056] In some embodiments, when the spectral absorption layer contains the same material as the active material species contained in the organic active layer, the spectral absorption range of the spectral absorption layer is partially overlapped with the spectral absorption range of the organic active layer by regulating and / or selecting one or more of the following items of the photodetector:

[0057] Item 2: the ratio of materials in the spectral absorption layer and / or the organic active layer (e.g. the weight ratio of electron donor material to electron acceptor material in the organic active layer and / or the weight ratio of materials in the spectral absorption layer);

[0058] Item 3: the concentration of materials in the solution comprising the materials used to form the spectral absorption layer and / or the organic active layer;

[0059] Item 4: the thickness of the spectral absorption layer and / or the organic active layer.

[0060] In some embodiments, the spectral absorption layer comprises a material which is not the same as the material species comprised in the organic active layer but has the same or similar absorption spectrum. For example, the spectral absorption layer comprises F-CHO and the material species comprised in the organic active layer is P3HT and PCBM.

[0061] In some embodiments, the spectral absorption layer is composed of a material which has the same or similar absorption spectrum to the active material species which makes up the organic active layer.

[0062] In some embodiments, the concentration of electron donor material (e.g. D18, PM6) in the solution comprising the materials used to form the spectral absorption layer and the organic active layer (e.g. the solution used to form the desired layers by solution spin coating) can each independently be 1 mg ml -1 to 40 mg ml -1 (e.g. 1 mg ml -1 , 2 mg ml -1 , 5 mg ml -1 , 8 mg ml -1 , 9 mg ml -1 , 10 mg ml -1 , 11 mg ml -1 , 13 mg ml -1 , 15 mg ml -1 , 18 mg ml -1 , 19 mg ml -1 , 20 mg ml -1 , 21 mg ml -1 , 22 mg ml -1 , 25 mg ml -1 , 28 mg ml -1 , 29 mg ml -1 , 30 mg ml -1 , 32 mg ml -1 , 34 mg ml -1 , 36 mg ml -1 , 38 mg ml -1or 40 mg ml -1 ) or 5 mg ml -1 to 30 mg ml -1 .

[0063] In some embodiments, the photodetector further comprises an electron transport layer and a hole transport layer disposed between the first electrode and the second electrode.

[0064] In some embodiments, wherein the organic active layer is disposed between the electron transport layer and the hole transport layer.

[0065] In some embodiments, the photodetector further comprises a transparent substrate.

[0066] In some embodiments, the photodetector is a forward device or a reverse device.

[0067] In some embodiments, the photodetector comprises a first electrode, a hole transport layer, an organic active layer, an electron transport layer, a second electrode, a transparent substrate, and a spectral absorption layer disposed in sequence.

[0068] In some embodiments, the photodetector comprises a first electrode, an electron transport layer, an organic active layer, a hole transport layer, a second electrode, a transparent substrate, and a spectral absorption layer disposed in sequence.

[0069] In some embodiments, the second electrode is a transparent electrode.

[0070] In some embodiments, the second electrode is a bottom electrode.

[0071] In some embodiments, the electron donor material is selected from one or a combination of materials of organic polymers and organic small molecules (including polymers and small molecules with conjugated structure composed of benzene ring, thiophene ring, alkyl chain, etc.), such as but not limited to: poly(3-hexylthiophene-2,5-diyl) (P3HT), PM6, PCE-10, D18.

[0072] In some embodiments, the electron acceptor material can be selected from one or a combination of materials of organic polymers and organic small molecules, such as including but not limited to: PCBM, F(Br)-ThCl, F-M, F-2F, FO-2F, CH17, ITIC, Y6, F-2Cl, FO-2Cl, COi8DFIC, DTPC-DFIC. In some embodiments, the electron acceptor material is selected from PCBM, F(Br)-ThCl, F-M, F-2F, FO-2Cl, CH17, COi8DFIC, or a combination thereof. The spectral absorption range is distributed from ultraviolet light (300 nm) to near-infrared light (1700 nm).

[0073] In some embodiments, the preparation of the organic active layer includes blending the electron donor material with the electron acceptor material to prepare an active layer structure, or obtaining a bilayer or multilayer structure by layer-by-layer preparation of donor material thin film and acceptor material thin film.

[0074] In some embodiments, the organic active layer is a blended bulk heterojunction thin film structure.

[0075] In some embodiments, the preparation of the organic active layer includes a step of blending the electron donor material with the electron acceptor material in a solvent to obtain an active solution.

[0076] In some embodiments, the solvent includes, but is not limited to, chloroform, organic solvents containing benzene ring, and combinations thereof. In some embodiments, the solvent is selected from chloroform, chlorobenzene, dichlorobenzene, toluene, or any combination thereof.

[0077] In some embodiments, the organic active layer can be formed using various methods including, but not limited to, spin coating, evaporation, blade coating, printing, slot coating, or combinations thereof. In some embodiments, the organic active layer is formed using solution spin coating method.

[0078] In some embodiments, the spectral absorption layer can be formed using various methods including, but not limited to, spin coating, evaporation, blade coating, printing, slot coating, or combinations thereof. In some embodiments, the spectral absorption layer is formed using solution spin coating method.

[0079] In some embodiments, the transparent substrate can be a rigid or flexible transparent substrate; the transparent substrate can be selected from any one of inorganic material, organic transparent material, inorganic transparent substrate including, but not limited to, glass, quartz, etc.; organic transparent substrate including, but not limited to, polyethylene terephthalate (PET), polyimide (PI), polydimethylsiloxane (PDMS), styrene-ethylene-butylene-styrene (SEBS), polymethyl methacrylate (PMMA), polyethylene 2,6-naphthalate (PEN), etc. In some embodiments, the transparent substrate is selected from glass or PEN. The transparent substrate has certain transparency and mechanical strength.

[0080] In some embodiments, the transparent electrode can be a conductive material with intrinsic light transmittance or a transparent conductive thin film with certain light transmittance composed of non-transparent materials. The transparent electrode includes, but is not limited to, metal oxides, metal thin films, organic conductive materials, conductive nanomaterials, or any combination thereof. In some embodiments, the transparent electrode includes, but is not limited to, one or more of a combination of indium tin oxide (ITO), graphene thin film, silver nanowire thin film, silver nanoparticle mesh, carbon nanotube thin film, MXene, poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS). In some embodiments, the transparent electrode material is indium tin oxide.

[0081] In some embodiments, the electron transport layer can be an N-type semiconductor material, including, but not limited to, organic polymers, metal oxides, organic small molecules, and all materials with N-type semiconductor properties, such as one or more of a combination of zinc oxide (ZnO), N,N'-bis[3-(dimethylamino)propyl]perylene-3,4,9,10-tetracarboxylic diimide (PDIN), N,N'-bis(N,N-dimethylpropane-1-oxylammonium)perylene-3,4,9,10-tetracarboxylic diimide (PDINO), poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylammonium propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene))dibromide (PFNBr). In some embodiments, the electron transport layer is zinc oxide. The electron transport layer can effectively transport electrons and block the transport of holes.

[0082] In some embodiments, the hole transport layer can be an organic or inorganic semiconductor, including P-type semiconductors and the like. In some embodiments, the hole transport layer includes, but is not limited to, one or more of a combination of molybdenum oxide (MoOx), nickel oxide (NiO), poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PSS:PEDOT). In some embodiments, the hole transport layer is selected from molybdenum oxide and PSS:PEDOT. The hole transport layer can effectively transport holes and block the transport of electrons.

[0083] In some embodiments, the method of preparing the electron transport layer and the hole transport layer includes, but is not limited to, spin coating, printing, blade coating, spraying, evaporation, or a combination thereof.

[0084] In some embodiments, the first electrode includes, but is not limited to, a metal electrode, a conductive polymer, a nanometer conductive material, a metal oxide conductive thin film, or a combination thereof. In some embodiments, the material of the first electrode includes, but is not limited to, gold, aluminum, silver, poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate, carbon nanotube thin film, silver nanowire thin film, or a combination thereof.

[0085] In some embodiments, the first electrode is a silver thin film.

[0086] In some embodiments, the first electrode is a top electrode.

[0087] In some embodiments, the method of preparing the first electrode includes, but is not limited to, evaporation, spray coating, screen printing, and the like. In some embodiments, the silver electrode is prepared as the first electrode by evaporation.

[0088] In some embodiments, the method of preparing the second electrode includes, but is not limited to, evaporation, doctor blading, screen printing, printing, physical lithography, chemical lithography.

[0089] In some embodiments, the spectral response range of the organic photodetector includes 550-700 nm (capable of detecting 550-700 nm band light), wherein the organic active layer comprises D18 and PCBM, and the spectral absorption layer comprises D18 and F(Br)-ThCl. In some embodiments, the mass ratio of D18 to PCBM in the organic active layer is 1:0.5-1:10 (e.g., 1:0.5, 1:0.8, 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10, etc.), or 1:0.5-1:5. In some embodiments, the mass ratio of D18 to F(Br)-ThCl in the spectral absorption layer is 1:0.5-1:10 (e.g., 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10, etc.), or 1:0.5-1:5. In some embodiments, the concentration of D18 in the solution used to form the spectral absorption layer and the organic active layer (e.g., the solution used to form the desired layer by solution spin coating method) can each independently be 1 mg ml -1 to 40 mg ml -1 (e.g., 1 mg ml -1 , 2 mg ml -1 , 5 mg ml -1 , 8 mg ml -1 , 9 mg ml -1 , 10 mg ml -1 , 11 mg ml -1 , 13 mg ml -1 , 15 mg ml -1 , 18 mg ml -1 , 19 mg ml -1 , 20 mg ml -1 , 21 mg ml -1, 22 mg ml -1 , 25 mg ml -1 , 28 mg ml -1 , 29 mg ml -1 , 30 mg ml -1 , 32 mg ml -1 , 34 mg ml -1 , 36 mg ml -1 , 38 mg ml -1 or 40 mg ml -1 ) or 5 mg ml -1 to 30 mg ml -1 . In some embodiments, the thickness of the organic active layer is 50 nm to 300 nm (e.g., 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, or 300 nm). In some embodiments, the thickness of the spectral absorption layer is 300 nm to 600 nm (e.g., 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, 420 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 570 nm, 580 nm, 590 nm, or 600 nm).

[0090] In some embodiments, the spectral response range of the organic photodetector includes 650 nm to 780 nm (capable of detecting light in the 650 nm to 780 nm band), wherein the organic active layer comprises PM6 and F-2F, and the spectral absorption layer comprises PM6. In some embodiments, the mass ratio of PM6 to F-2F in the organic active layer is 1 : 0.5 to 1 : 10 (e.g., 1 : 0.5, 1 : 0.8, 1 : 1, 1 : 1.5, 1 : 2, 1 : 3, 1 : 4, 1 : 5, 1 : 6, 1 : 7, 1 : 8, 1 : 9, or 1 : 10, etc.), or 1 : 0.5 to 1 : 5. In some embodiments, the concentration of PM6 in the solution used to form the spectral absorption layer and the organic active layer (e.g., the solution used to form the desired layers by solution spin coating) can each independently be 1 mg ml -1 to 40 mg ml -1 (e.g., 1 mg ml -1 , 2 mg ml -15 mg ml -1 8 mg ml -1 9 mg ml -1 10 mg ml -1 11 mg ml -1 13 mg ml -1 15 mg ml -1 18 mg ml -1 19 mg ml -1 20 mg ml -1 21 mg ml -1 22 mg ml -1 25 mg ml -1 28 mg ml -1 29 mg ml -1 30 mg ml -1 32 mg ml -1 34 mg ml -1 36 mg ml -1 38 mg ml -1 or 40 mg ml -1 ) or 5 mg ml -1 to 30 mg ml -1 In some embodiments, the organic active layer has a thickness of 50 nm to 300 nm (e.g., 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, or 300 nm). In some embodiments, the spectral absorption layer has a thickness of 300 nm to 600 nm (e.g., 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, 420 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 570 nm, 580 nm, 590 nm, or 600 nm).

[0091] In some embodiments, the spectral response range of the organic photodetector includes 750-850 nm (capable of detecting light in the 750-850 nm band), wherein the organic active layer comprises PM6 and FO-2F, and the spectral absorption layer comprises PM6 and F-2F. In some embodiments, the mass ratio of PM6 to FO-2F in the organic active layer is 1:0.5-1:10 (e.g., 1:0.5, 1:0.8, 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10, etc.), or 1:0.5-1:5. In some embodiments, the mass ratio of F-2F to PM6 in the spectral absorption layer is 1:0.5-1:10 (e.g., 1:0.5, 1:0.8, 1:1, 1:1.5, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10, etc.), or 1:0.5-1:5. In some embodiments, the concentration of PM6 in the solution used to form the spectral absorption layer and the organic active layer (e.g., the solution used to form the desired layers by solution spin coating) can each independently be 1 mg ml -1 to 40 mg ml -1 (e.g., 1 mg ml -1 , 2 mg ml -1 , 5 mg ml -1 , 8 mg ml -1 , 9 mg ml -1 , 10 mg ml -1 , 11 mg ml -1 , 13 mg ml -1 , 15 mg ml -1 , 18 mg ml -1 , 19 mg ml -1 , 20 mg ml -1 , 21 mg ml -1 , 22 mg ml -1 , 25 mg ml -1 , 28 mg ml -1 , 29 mg ml -1 , 30 mg ml -1 , 32 mg ml -1 , 34 mg ml -1 , 36 mg ml -1 , 38 mg ml -1 , or 40 mg ml -1 ) or 5 mg ml -1 to 30 mg ml -1In some embodiments, the thickness of the organic active layer is 50 nm - 300 nm (e.g., 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, or 300 nm). In some embodiments, the thickness of the spectral absorption layer is 300 nm - 600 nm (e.g., 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, 420 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 570 nm, 580 nm, 590 nm, or 600 nm).

[0092] In some embodiments, the spectral response range of the organic photodetector includes 800 nm - 950 nm (capable of detecting light in the 800 nm - 950 nm band), wherein the organic active layer comprises PM6 and CH17, and the spectral absorption layer comprises PM6 and CH17. In some embodiments, the mass ratio of PM6 to CH17 in the organic active layer is 1 : 0.5 - 1 : 10 (e.g., 1 : 0.5, 1 : 0.8, 1 : 1, 1 : 1.5, 1 : 2, 1 : 3, 1 : 4, 1 : 5, 1 : 6, 1 : 7, 1 : 8, 1 : 9, or 1 : 10, etc.), or 1 : 0.5 - 1 : 5. In some embodiments, the mass ratio of PM6 to CH17 in the spectral absorption layer is 1 : 0.05 - 1 : 10 (e.g., 1 : 0.05, 1 : 0.07, 1 : 0.08, 1 : 0.1, 1 : 0.2, 1 : 0.3, 1 : 0.4, 1 : 0.5, 1 : 0.8, 1 : 1, 1 : 1.5, 1 : 2, 1 : 3, 1 : 4, 1 : 5, 1 : 6, 1 : 7, 1 : 8, 1 : 9, or 1 : 10, etc.), or 1 : 0.5 - 1 : 5. In some embodiments, the concentration of PM6 in the solution used to form the spectral absorption layer and the organic active layer (e.g., the solution used to form the desired layers by solution spin coating) can each independently be 1 mg ml -1 to 40 mg ml -1 (e.g., 1 mg ml -1 , 2 mg ml -1 , 5 mg ml -1 , 8 mg ml -1 , 9 mg ml -1 , 10 mg ml -1 , 11 mg ml-1 13 mg ml -1 15 mg ml -1 18 mg ml -1 19 mg ml -1 20 mg ml -1 21 mg ml -1 22 mg ml -1 25 mg ml -1 28 mg ml -1 29 mg ml -1 30 mg ml -1 32 mg ml -1 34 mg ml -1 36 mg ml -1 38 mg ml -1 or 40 mg ml -1 ) or 5 mg ml -1 to 30 mg ml -1 In some embodiments, the thickness of the organic active layer is 50 nm to 300 nm (e.g., 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, or 300 nm). In some embodiments, the thickness of the spectral absorption layer is 300 nm to 600 nm (e.g., 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, 420 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, 550 nm, 560 nm, 570 nm, 580 nm, 590 nm, or 600 nm).

[0093] In another aspect, the present application provides a device comprising the organic photodetector described above.

[0094] In some embodiments, the device includes, but is not limited to, an imaging recognition system, a wearable device, a robot, an implantable device, and a device for health monitoring, motion monitoring, obstacle detection.

[0095] In another aspect, the present application provides a method for preparing an organic photodetector, comprising:

[0096] providing a first electrode;

[0097] providing a second electrode; and

[0098] providing an organic active layer between the first electrode and the second electrode; and

[0099] providing a spectral absorption layer such that a spectral absorption range of the spectral absorption layer partially overlaps with a spectral absorption range of the organic active layer.

[0100] In some embodiments, the method of making further comprises selecting an electron donor material and an electron acceptor material of the organic active layer according to a desired spectral response range.

[0101] In some embodiments, the method of making further comprises fabricating the spectral absorption layer using a material whose absorption spectrum is the same or similar to that of an active material species (i.e., active material component) included in the organic active layer.

[0102] In some embodiments, the method of making further comprises positioning the spectral absorption layer in a manner such that it is passed through by incident light of the organic active layer first.

[0103] In some embodiments, the method of making further comprises regulating a spectral absorption range of the spectral absorption layer and / or a spectral absorption range of the organic active layer according to a desired spectral response range such that a portion of the spectral absorption range of the spectral absorption layer and / or the spectral absorption range of the organic active layer that does not overlap includes the desired spectral response range.

[0104] In some embodiments, the spectral absorption range of the spectral absorption layer and / or the spectral absorption range of the organic active layer is regulated by regulating and / or selecting one or more of the following of the photodetector:

[0105] Item 1 : a species of material in the spectral absorption layer and / or the organic active layer;

[0106] Item 2: a ratio of materials in the spectral absorption layer and / or the organic active layer (e.g., a weight ratio of an electron donor material to an electron acceptor material in the organic active layer and / or a weight ratio of materials in the spectral absorption layer);

[0107] Item 3: a concentration of a material in a solution including the material used to form the spectral absorption layer and / or the organic active layer;

[0108] Item 4: a thickness of the spectral absorption layer and / or the organic active layer.

[0109] Thus, selective detection of light can be achieved, and high-selectivity detection of narrow-band light in the full waveband range of visible light-near infrared light can be achieved.

[0110] In some embodiments, the required spectral response range is a narrow-band spectral response range.

[0111] Each abbreviation represents the following structure:

[0112]

[0113]

[0114]

[0115] The present application provides one or more of the following advantages:

[0116] 1. The organic photodetector of the present disclosure can achieve selective high-sensitivity detection of any required different waveband narrow-band light in the full wide spectral range of visible light-near infrared light, and the active layer can efficiently absorb the detected light and generate photo-generated carriers, converting the light signal into an electrical signal to achieve selective high-sensitivity detection of narrow-band light.

[0117] 2. The novel organic photodetector and the preparation method thereof of the present disclosure can achieve high-selectivity detection of light or even narrow-band light without sacrificing the light response speed, responsivity, and sensitivity.

[0118] 3. The organic photodetector of the present disclosure can solve the problems of high cost and low performance faced by current narrow-band light detectors, and a simple structure, low-cost, and excellent performance narrow-band light detector is designed and prepared, and through the synergistic effect of the device structure and the active material, high-sensitivity and rapid detection of any narrow-band spectrum in the wide range of visible light-near infrared light is achieved.

[0119] 4. The present disclosure provides an effective method for constructing high-performance and high-selectivity organic photodetectors, which is suitable for all organic photodetectors and has very wide applicability.

[0120] 5. The organic photodetector of the present disclosure maintains the high response speed performance of the organic photodetector, and the response time can be less than 1 microsecond.

[0121] 6. The organic photodetector of the present disclosure can achieve high-selectivity detection of different waveband light in the full waveband range of visible light-near infrared light, and the half-peak width can be less than 150 nm (e.g., less than 140 nm, less than 130 nm, less than 120 nm, less than 110 nm, less than 100 nm, less than 90 nm, less than 80 nm, less than 70 nm, less than 60 nm, less than 50 nm, etc.).

[0122] 7. The organic photodetector of the present disclosure can have a peak responsivity of 0.3 A / W or more at a full width at half maximum of 50 nm.

[0123] 8. The organic photodetector of the present disclosure can achieve high sensitivity and high selective detection of light at 0 V without any external driving voltage.

[0124] 9. The organic photodetector of the present disclosure has low noise (e.g., less than 10 -4 mA / cm 2 ).

[0125] 10. The organic photodetector of the present disclosure has a simple structure and low requirements for the light spectrum absorption layer. The material of the organic active layer can be directly used as the light spectrum absorption layer, thereby improving the selectivity of the light detector. In addition, a material with a light absorption spectrum similar to that of the organic active layer can also be selected as the light spectrum absorption layer, thereby improving the selectivity and performance. The present disclosure has great advantages and potential in the preparation of large-area narrow-band light detectors.

[0126] 11. The organic photodetector of the present disclosure has advantages such as flexibility, solution processability, and low cost. The present disclosure can realize large-area preparation of high-performance, low-cost, large-area narrow-band light detectors through a solution method, and has great market and industrialization potential.

[0127] Examples

[0128] The specific embodiments of the present disclosure will be further described in detail below with reference to the examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0129] Example 1:

[0130] The structure of the organic photodetector is shown in Figure 1 , which includes (1) a light spectrum absorption layer, (2) a transparent substrate, (3) a transparent conductive bottom electrode, (4) a hole transport layer, (5) an organic active layer, (6) an electron transport layer, and (7) a metal electrode

[0131] As shown in Figure 1 , the transparent substrate is glass, the transparent conductive electrode is indium tin oxide (ITO), the electron transport layer is zinc oxide, the organic active layer is D18:PCBM, and the light spectrum absorption layer is D18 and F(Br)-ThCl.

[0132] The preparation steps of the organic narrow-band light detector of Example 1 are as follows:

[0133] The ITO conductive layer coated glass (wherein the thickness of the glass substrate and the conductive layer is 0.8 mm and 10 nm respectively) was cleaned by acetone, deionized water, isopropanol in sequence, and then dried by nitrogen gun, and placed in a clean culture dish. The ITO conductive glass used for preparing the light detector was placed in an ozone treatment device and treated with ozone for 15 min to improve its hydrophilicity.

[0134] Poly 3,4-ethylenedioxythiophene / polystyrene sulfonate (PEDOT:PSS, Baytron PVP Al4083) was diluted twice with distilled water, and was dispersed by ultrasonic and spin-coated on the conductive glass as a hole transport layer at a spin speed of 4300 rpm for 20 s. Then, it was dried in an oven at 150 ℃ for 15 min, and then transferred to a glove box.

[0135] D18 and PCBM were dissolved in chloroform solvent as donor and acceptor materials (mass ratio of 1:1.2) respectively, and the concentration of the donor was 9 mg / ml -1 at 50 ℃ for 5 h.

[0136] The D18:PCBM mixed solution was spin-coated on the PEDOT:PSS layer at a spin speed of 2000 rpm for 30 s to form a bulk heterojunction with a thickness of about 130 nm. Then, the device was placed in chloroform vapor for 10 min.

[0137] PDINO was dissolved in methanol with a concentration of 1 mg / mL, and the PDINO solution was spin-coated on the top of the bulk heterojunction film at a spin speed of 3000 rpm for 30 s to obtain an electron transport layer with a thickness of about 15 nm.

[0138] A layer of Ag with a thickness of 150 nm was vacuum evaporated on the electron transport layer as a top electrode for collecting electrons.

[0139] D18 and F(Br)-ThCl (mass ratio of 1:1.2) were dissolved in chloroform solvent to prepare a spectral absorption layer solution, and the concentration of D18 was 9 mg / ml -1 .

[0140] The spectral absorption layer solution was spin-coated on the back of the ITO glass as a spectral absorption layer at a spin speed of 1000 rpm for 30 s to form a spectral absorption layer with a thickness of 500 nm. By complementing the detection spectrum of the organic active layer, high sensitivity and high response to narrow-band light were achieved, and high selective detection of light with a wavelength of 550-700 nm was achieved, and the half peak width could reach 80 nm (see Figure 2 ).

[0141] Example 2

[0142] The active layer material in Example 1 is replaced by PM6 and F-2F, and PM6 is used as the spectral absorption layer material, which can absorb all light with a wavelength of 650 nm or less, realizing high selective detection of light with a wavelength of 650 nm-780 nm, and the half-peak width can reach 60 nm. The specific implementation steps are as follows:

[0143] The ITO conductive glass (wherein the thickness of the glass substrate and the conductive layer is 0.8 mm and 10 nm respectively) is cleaned by acetone, deionized water, isopropyl alcohol in turn, and then dried by nitrogen gun, and placed in a clean culture dish. The ITO conductive glass used for preparing the light detector is placed in an ozone treatment device and treated with ozone for 15 min to improve its hydrophilicity.

[0144] Dissolve 100 mg of zinc acetate in 4 ml of 2-methoxyethanol and add 28 ul of ethanolamine. Stir the obtained solution for 8 h.

[0145] Place the treated ITO glass substrate and zinc acetate solution into a glove box, and spin-coat the uniformly dissolved zinc acetate solution onto the ITO glass at a speed of 3000 rpm for 30 s. Then place it on a hot stage at 210°C for drying and annealing for 1 hour to obtain a zinc oxide film with a thickness of 30 nm as an electron transport layer film, and place it in a glove box.

[0146] Dissolve PM6 and F-2F (mass ratio 1:1) as donor and acceptor materials respectively in chlorobenzene, with a donor concentration of 9 mg ml -1 , and stir and dissolve at 50°C for 5 h.

[0147] Spin-coat the mixed PM6 and F-2F solution onto the surface of the electron transport layer ZnO at a spin speed of 1700 rpm for 30 s to form a bulk heterojunction film with a thickness of about 120 nm. Then, place the device on a hot stage and heat at 120°C for 10 min.

[0148] Vacuum evaporate a layer of MoOx with a thickness of 3 nm as a hole transport layer on the active layer, and evaporate 100 nm of silver as a top electrode for collecting holes.

[0149] Dissolve PM6 as a spectral absorption layer material in chloroform solvent to obtain a spectral absorption layer solution with a concentration of 20 mg ml -1The spectral absorption layer solution was spin-coated on the back of the ITO glass as a spectral absorption layer, with a spin speed of 500 rpm and a spin time of 1 min, and the thickness of the formed spectral absorption layer was 500 nm. The spectral absorption layer can form a complement with the detection spectrum of the active layer, achieving high sensitivity, high response, and high selectivity detection of narrow-band light, with a half-peak width of 60 nm (see Figure 3 ).

[0150] Example 3

[0151] The active layer material in Example 1 was replaced with PM6 and FO-2F, and PM6 and F-2F were used as spectral absorption layers, which could absorb all light with a wavelength of 750 nm or less, achieving high selectivity detection of light in the wavelength range of 750 nm-850 nm, with a half-peak width of 65 nm. The specific implementation steps are as follows:

[0152] The ITO conductive glass (with a glass substrate and a conductive layer thickness of 0.8 mm and 10 nm, respectively) was cleaned by acetone, deionized water, and isopropyl alcohol in sequence, and then dried with a nitrogen gun. The ITO conductive glass for preparing the light detector was placed in an ozone treatment device and treated with ozone for 15 min to improve its hydrophilicity.

[0153] 100 mg of zinc acetate was dissolved in 4 ml of 2-methoxyethanol and 28 ul of ethanolamine was added. The obtained solution was stirred at room temperature for 8 h.

[0154] The treated ITO glass substrate and zinc acetate solution were placed in a glove box, and the zinc acetate solution was spin-coated on the ITO glass at a speed of 3000 rpm for 30 s. Then, it was placed in an atmosphere containing oxygen (such as air) and dried and annealed at 210°C for 1 hour to obtain a zinc oxide film with a thickness of 30 nm as an electron transport layer film, and placed in a glove box.

[0155] PM6 and FO-2F (mass ratio 1:1) were dissolved in chlorobenzene as donor and acceptor materials, respectively, with a donor concentration of 9 mg ml -1 at 50°C for 5 h.

[0156] The above PM6:FO-2F mixed solution was spin-coated on the surface of the electron transport layer ZnO at a spin speed of 1700 rpm for 30 s to form a bulk heterojunction film with a thickness of about 120 nm. Then, the device was placed on a hot stage and heated at 120°C for 10 min.

[0157] A 3 nm-thick MoOx layer was vacuum-deposited on the active layer as a hole transport layer, and a 100 nm-thick silver layer was deposited as a top electrode for collecting holes.

[0158] PM6:F-2F (mass ratio of 10:1) was dissolved in chloroform solvent to obtain a spectral absorption layer solution, wherein the concentration of PM6 was 20 mg / ml -1 The spectral absorption layer solution was spin-coated on the back of the ITO glass as a spectral absorption layer, with a spin-coating speed of 500 rpm and a spin-coating time of 1 min, and the thickness of the formed spectral absorption layer was 500 nm. The spectral absorption layer can form a complement to the detection spectrum of the active layer, achieving high sensitivity, high response, and high selectivity detection of narrow-band light, with a half-peak width of 65 nm (see Figure 4 ).

[0159] Example 4

[0160] The active layer material in Example 1 was replaced by PM6 and CH17, and the mixed film of PM6 and CH17 was used as a spectral absorption layer material, which could absorb all light with a wavelength of 800 nm or less, achieving high selectivity detection of light in the wavelength range of 800 nm-950 nm, with a peak wavelength of 850 nm and a half-peak width of 65 nm. The specific implementation steps are as follows:

[0161] The ITO conductive glass (wherein the thickness of the glass substrate and the conductive layer was 0.8 mm and 10 nm, respectively) was cleaned by acetone, deionized water, and isopropyl alcohol in sequence, and then was blown dry with a nitrogen gun and placed in a clean culture dish. The ITO conductive glass used for preparing the light detector was placed in an ozone treatment device and treated with ozone for 15 min to improve its hydrophilicity.

[0162] 100 mg of zinc acetate was dissolved in 4 ml of 2-methoxyethanol and 28 ul of ethanolamine was added, and the obtained solution was stirred at room temperature for 8 h.

[0163] The treated ITO glass substrate was placed in a glove box with the zinc acetate solution, and the zinc acetate solution was spin-coated on the ITO glass at a speed of 3000 rpm for 30 s, and then was placed in an atmosphere containing oxygen (such as air) and dried and annealed at 210°C for 1 hour to obtain a 30 nm-thick zinc oxide film as an electron transport layer film, and was placed in a glove box.

[0164] PM6 and CH17 were used as donor and acceptor materials (mass ratio of 1:1), respectively, and were dissolved in chloroform, with a donor concentration of 9 mg / ml -1 , and were stirred at 50°C for 5 h.

[0165] The PM6:CH17 mixed solution was spin-coated onto the surface of the electron transport layer ZnO at a spin speed of 1700 rpm for 30 s to form a bulk heterojunction film with a thickness of about 120 nm. Then, the device was placed on a hot stage and heated at 100°C for 10 min.

[0166] A layer of MoOx with a thickness of 3 nm was vacuum evaporated on the active layer as a hole transport layer, and 100 nm of silver was evaporated as a top electrode for collecting holes.

[0167] PM6:CH17 was dissolved in chloroform at a mass ratio of 1:1; 1:0.8; 1:0.6; 1:0.4 and 1:0.2, respectively, wherein the concentration of PM6 was 20 mg / ml -1 The spectral absorption layer solution was spin-coated onto the back of the ITO glass as a spectral absorption layer at a spin speed of 500 rpm for 1 min to form a spectral absorption layer with a thickness of 500 nm. The spectral absorption layer can form a complement with the detection spectrum of the active layer to achieve high-sensitivity, high-response, and high-selectivity detection of narrow-band light, with a half-peak width of 65 nm, as shown in Figure 5 (wherein the mass ratio of PM6:CH17 is 1:0.4), and Figure 6 (wherein the mass ratio of PM6:CH17 is 1:1; 1:0.8; 1:0.6; 1:0.4 and 1:0.2, respectively).

[0168] The present disclosure has been described in detail with general description and specific embodiments, but some modifications or improvements can be made on the basis of the present disclosure, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present disclosure, all belong to the scope of protection required by the present disclosure.

Claims

1. An organic photodetector, comprising: a first electrode, a hole transport layer, an organic active layer, an electron transport layer, a second electrode, a transparent substrate and a spectral absorption layer arranged in sequence; or a first electrode, an electron transport layer, an organic active layer, a hole transport layer, a second electrode, a transparent substrate and a spectral absorption layer arranged in sequence; wherein the spectral absorption range of the spectral absorption layer partially overlaps with the spectral absorption range of the organic active layer.

2. The photodetector of claim 1, wherein: the spectral absorption layer is positioned such that the incident light travels through the spectral absorption layer first relative to the organic active layer; or the non-overlapping part of the spectral absorption range of the spectral absorption layer and the spectral absorption range of the organic active layer comprises a spectral response range; or the half-peak width of the non-overlapping part is no more than 150 nm, no more than 100 nm or no more than 80 nm; the organic active layer comprises an electron donor material and an electron acceptor material.

3. The photodetector of claim 1 or 2, the spectral absorption layer comprises a spectral absorption material with an absorption spectrum identical or similar to the absorption spectrum of the active material species contained in the organic active layer; wherein: the spectral absorption layer comprises a spectral absorption material identical or different to the active material species contained in the organic active layer; or the spectral absorption layer comprises a spectral absorption material partially identical to the material species contained in the organic active layer; or the spectral absorption layer comprises a spectral absorption material entirely identical to the active material species contained in the organic active layer; or the spectral absorption layer comprises a spectral absorption material not identical to the material species contained in the organic active layer.

4. The photodetector of claim 3, the spectral absorption range of the spectral absorption layer partially overlaps with the spectral absorption range of the organic active layer by regulating and / or selecting one or more of the following items of the photodetector: item 1: the kind of material in the spectral absorption layer and / or the organic active layer; item 2: the ratio of the material in the spectral absorption layer and / or the organic active layer; item 3: the concentration of the material in the solution comprising the material used to form the spectral absorption layer and / or the organic active layer; item 4: the thickness of the spectral absorption layer and / or the organic active layer.

5. The photodetector of claim 1, wherein: the photodetector is a forward device or a reverse device; or the second electrode is a transparent electrode; or the second electrode is a bottom electrode; or the first electrode is a top electrode.

6. An apparatus comprising the photodetector of any one of claims 1 to 5. An imaging recognition system, a wearable device, a robot, an implantable device, and a device for health monitoring, motion monitoring, obstacle detection.

8. A method for preparing an organic photodetector, comprising: arranging a first electrode, a hole transport layer, an organic active layer, an electron transport layer, a second electrode, a transparent substrate and a spectral absorption layer in sequence; or ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. The apparatus of claim 6, comprising: ​ ​ ​ ​ The first electrode, the electron transport layer, the organic active layer, the hole transport layer, the second electrode, the transparent substrate and the spectral absorption layer are arranged in sequence; and The spectral absorption layer is provided such that the spectral absorption range of the spectral absorption layer partially overlaps with the spectral absorption range of the organic active layer.

9. The method of claim 8, further comprising: selecting the electron donor material and the electron acceptor material of the organic active layer according to the required spectral response range; or fabricating the spectral absorption layer using a material whose absorption spectrum is the same as or similar to that of the active material species contained in the organic active layer; or positioning the spectral absorption layer in such a way that the incident light travels through the spectral absorption layer first relative to the organic active layer.

10. The method of claim 8 or 9, further comprising: regulating the spectral absorption range of the spectral absorption layer and / or the spectral absorption range of the organic active layer according to the required spectral response range, such that the portion of the spectral absorption range of the spectral absorption layer and the spectral absorption range of the organic active layer that do not overlap includes the required spectral response range.

11. The method of claim 10, the spectral absorption range of the spectral absorption layer and / or the spectral absorption range of the organic active layer is regulated by regulating and / or selecting one or more of the following items of the photodetector: Item 1: the species of the materials in the spectral absorption layer and / or the organic active layer; Item 2: the ratio of the materials in the spectral absorption layer and / or the organic active layer; Item 3: the concentration of the materials in the solution containing the materials used to form the spectral absorption layer and / or the organic active layer; Item 4: the thickness of the spectral absorption layer and / or the organic active layer.

Images