Photodetector and device comprising a photodetector and active material therefor

Abstract

The present application relates to an organic photodetector, a device comprising the organic photodetector and an active material therefor. The photodetector of the present application comprises: a first electrode; a second electrode; and a light-sensing active layer disposed between the first electrode and the second electrode, wherein the light-sensing active layer comprises a compound of Formula I. The organic photodetector of the present application can achieve high sensitivity and rapid detection of different waveband light in the ultraviolet-visible-near infrared full spectral range. Wherein R 1 to R 6 as defined herein.

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 and a device (such as an imaging recognition system, a wearable device, a robot, an implantable device, and a device for health monitoring, motion monitoring, obstacle detection, etc.) comprising the organic photodetector and an active material therefor. BACKGROUND

[0002] A photodetector can convert a light signal into an electrical signal, realize detection of the wavelength and intensity of light, and has a wide application in the fields of military, aerospace, biological medicine, image sensing, etc. SUMMARY

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

[0004] a first electrode;

[0005] a second electrode; and

[0006] a light-sensing active layer disposed between the first electrode and the second electrode, wherein the light-sensing active layer comprises a compound of Formula I:

[0007]

[0008] wherein:

[0009] R 1 to R 6 are each independently selected from C 2-12 alkyl.

[0010] In another aspect, the present application provides a device comprising the above photodetector.

[0011] In yet another aspect, the present application provides a compound of Formula I:

[0012]

[0013] wherein:

[0014] R 1 to R 6 are each independently selected from C 2-12 alkyl.

[0015] In still another aspect, the present application provides a method for preparing a photodetector, comprising: providing a first electrode;

[0016] providing a second electrode; and

[0017] disposing a light-sensing active layer between the first electrode and the second electrode, wherein the light-sensing active layer comprises a compound of Formula I:

[0018]

[0019] wherein:

[0020] R 1 to R 6 each independently is selected from C 2-12 alkyl. BRIEF DESCRIPTION OF DRAWINGS BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Structure schematic of the organic photodetector with reverse structure used in Example 1.

[0022] Figure 2 Structure schematic of the organic photodetector with forward structure used in Example 2.

[0023] Figure 3 Plot of the spectral responsivity of the organic photodetector prepared in Example 1.

[0024] Figure 4 Plot of the dark current density of the organic photodetector prepared in Example 1.

[0025] Figure 5A and Figure 5B Plots of the spectral specific detectivity of the organic photodetector and comparative organic photodetector prepared in Example 1, respectively.

[0026] Figure 6 Plot of the response time of the organic photodetector prepared in Example 1 under visible light.

[0027] Figure 7 Plot of the response time of the organic photodetector prepared in Example 1 under near-infrared light.

[0028] Figure 8 Schematic of the cathode bottom electrode design of the organic photodetector array with reverse structure used in Example 1.

[0029] Figure 9 Schematic of the anode top electrode design of the organic photodetector array with reverse structure used in Example 1.

[0030] Figure 10 Structure schematic of the near-infrared organic photodetector array with reverse structure used in Example 1.

[0031] Figure 11 A nuclear magnetic resonance hydrogen spectrum of compound 1 is shown.

[0032] Figure 12 A mass spectrum of compound 1 is shown. DETAILED DESCRIPTION

[0033] Definitions

[0034] 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 defined, terms are to be understood according to their common use by those of ordinary skill in the art. All patents, academic papers, and other publications cited herein are incorporated by reference in their entirety.

[0035] As used herein, the terms "comprises," "comprising," "includes," "including," and the like are to be construed as being inclusive (i.e., open-ended) and not exclusive, unless expressly restricted otherwise. Specifically, when used in the specification and claims, the terms "comprises," "comprising," "includes," "including," and the like mean that the named feature is included as a component, material, step, or the like, but not that other features, components, steps, or the like are excluded.

[0036] The term "optional" or "optionally" as used herein 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.

[0037] The term "alkyl" refers to a saturated hydrocarbon group of the general formula C n H 2n+1 The alkyl group can be straight-chained or branched. For example, the term "C 2-12 alkyl" refers to an alkyl group containing 2 to 12 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, examples of which include, but are not limited to, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, neopentyl, 2-methylpentyl, t-amyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, t-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, n-nonyl, n-decyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-undecyl, n-dodecyl, and the like).

[0038] 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. The spatially relative terms are intended to encompass different orientations of the device in use, operation and / or manufacture in addition to the orientations 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 exemplary term "above" can encompass both an orientation that is above and then below. The devices can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0039] 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. For the purposes of this disclosure, the term "directly on" or "directly connected to" means that the element is in direct contact therewith. Likewise, 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 contrast, when an element such as a layer, region, or substrate is referred to as being "directly between" two other elements, there are no intervening elements present. For the purposes of this disclosure, the term "directly between" means that the element is in direct contact with the two other elements.

[0040] 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.

[0041] "Mxene" is a two-dimensional material, a class of transition metal carbide, transition metal nitride or transition metal carbonitride with two-dimensional layered structure, a new type of material similar to graphene obtained by processing MAX phase.

[0042] 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 and every possible combination of any of the ranges with any of the other ranges, to the same extent, as if each and every such combination were explicitly stated. For example, a mass ratio of the electron donor material to the electron acceptor material of 1 :0.1-1 :100 means that the mass ratio can be 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, 1 :10, 1 :15, 1 :20, 1 :25, 1 :30, 1 :35, 1 :40, 1 :45, 1 :50, 1 :55, 1 :60, 1 :65, 1 :70, 1 :75, 1 :80, 1 :85, 1 :90, 1 :95, 1 :100, etc., and ranges formed by them, etc.

[0043] In one aspect, the present application provides a photodetector, comprising:

[0044] a first electrode;

[0045] a second electrode; and

[0046] a photoactive layer disposed between the first electrode and the second electrode,

[0047] wherein the photoactive layer comprises a compound of Formula I:

[0048]

[0049] wherein:

[0050] R 1 R 6 each independently selected from C 2-12 alkyl.

[0051] In some embodiments, R 1 R 6 each independently selected from C 4-12 alkyl.

[0052] In some embodiments, R 1 R 6 each independently selected from C 6-12 alkyl.

[0053] In some embodiments, the compound of Formula I is selected from:

[0054]

[0055] 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.

[0056] In some embodiments, wherein the photoactive layer is disposed between the electron transport layer and the hole transport layer.

[0057] In some embodiments, the photodetector further comprises a transparent substrate.

[0058] In some embodiments, the photodetector comprises a first electrode, a hole transport layer, a photoactive layer, an electron transport layer, a second electrode, and a transparent substrate disposed in sequence.

[0059] In some embodiments, the photodetector comprises a first electrode, an electron transport layer, a photoactive layer, a hole transport layer, a second electrode, and a transparent substrate disposed in sequence.

[0060] In some embodiments, the photodetector comprises a second electrode, an electron transport layer, a photoactive layer, a hole transport layer, a first electrode disposed in sequence on the transparent substrate.

[0061] In some embodiments, the photodetector comprises a second electrode, a hole transport layer, a photoactive layer, an electron transport layer, a first electrode disposed in sequence on the transparent substrate.

[0062] In some embodiments, the photodetector is a forward device or a reverse device. In some embodiments, the photodetector is a reverse device.

[0063] In some embodiments, the second electrode is a transparent electrode.

[0064] In some embodiments, the second electrode is a bottom electrode.

[0065] In some embodiments, the photoactive layer comprises the compound of Formula I as an electron acceptor material.

[0066] In some embodiments, the photoactive layer further comprises an electron donor material, wherein the electron donor material is selected from a material having a higher occupied molecular orbital (HOMO) energy level than the HOMO energy level of the electron acceptor material, for example, a polymer or a small molecule having a HOMO energy level higher than the electron acceptor material is selected as the electron donor material in order to match the energy level with the acceptor molecule material. For example, the HOMO energy level of the electron donor material, for example, Compound 1, is -5.28 eV, and a material having a HOMO energy level higher than -5.28 eV is selected as the electron donor material.

[0067] In some embodiments, the electron donor material is selected from the group consisting of commercially available PTB7-Th (also known as PCE-10), poly(3-hexylthiophene-2,5-diyl) (P3HT), or any combination thereof.

[0068]

[0069] In some embodiments, the electron donor material is selected from the group consisting of PCE-10, P3HT, PM6, and any combination thereof. In some embodiments, the electron donor material is PCE-10.

[0070] In some embodiments, the mass ratio of the electron donor material to the electron acceptor material is 1:0.1-1:100 (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, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80, 1:85, 1:90, 1:95, 1:100, etc.), or 1:0.5-1:5.

[0071] In some embodiments, the mass ratio of the donor material to the acceptor material is 1:1.5.

[0072] In some embodiments, the photo-sensing active layer further comprises an additive, which includes but is not limited to 1,8-diiodooctane (DIO), chloronaphthalene (CN), nitrobenzene (NB), or any combination thereof. In some embodiments, the additive is 1,8-diiodooctane (DIO).

[0073] In some embodiments, the preparation of the photo-sensing active layer comprises 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 photo-sensing active layer is a blended thin film structure.

[0075] In some embodiments, the preparation of the photo-sensing active layer comprises a step of blending the electron donor material with the electron acceptor material and an additive (if any) in a solvent to obtain an active solution.

[0076] In some embodiments, the solvent includes but is not limited to chloroform (CF), organic solvents containing benzene rings, and combinations thereof. In some embodiments, the solvent is selected from the group consisting of chlorobenzene (CB), dichlorobenzene (DCB), toluene (MB), or any combination thereof,

[0077] In some embodiments, the total concentration of both the electron donor material and the electron acceptor material in the active solution, i.e., the total concentration of active materials in the active solution, ranges from 0.01 mg / ml to 50 mg / ml (e.g., 0.01 mg / ml, 0.1 mg / ml, 1 mg / ml, 2 mg / ml, 3 mg / ml, 4 mg / ml, 5 mg / ml, 6 mg / ml, 7 mg / ml, 8 mg / ml, 9 mg / ml, 10 mg / ml, 12 mg / ml, 15 mg / ml, 18 mg / ml, 20 mg / ml, 23 mg / ml, 27 mg / ml, 30 mg / ml, 32 mg / ml, 35 mg / ml, 38 mg / ml, 40 mg / ml, 43 mg / ml, 47 mg / ml, 50 mg / ml, etc.), or from 10 mg / ml to 30 mg / ml. In some embodiments, the total concentration of active materials in the active solution is 18 mg / ml.

[0078] In some embodiments, the mass of the additive accounts for 0.01% to 50% (e.g., 0.01%, 0.05%, 0.1%, 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.) of the total mass of the active solution, or from 0.05% to 10%. In some embodiments, the mass of the additive accounts for 5% of the total mass of the active solution.

[0079] In some embodiments, the active layer can be formed using various methods, including but not limited to, spin coating, blade coating, printing, spraying, or a combination thereof. In some embodiments, the thickness of the active layer ranges from 1 nm to 500 nm (e.g., 1 nm, 10 nm, 20 nm, 50 nm, 80 nm, 100 nm, 110 nm, 120 nm, 150 nm, 180 nm, 200 nm, 250 nm, 280 nm, 300 nm, 320 nm, 350 nm, 380 nm, 400 nm, 420 nm, 460 nm, 480 nm, 500 nm, etc.), or from 50 nm to 300 nm. In some embodiments, the active layer is prepared by a spin coating method. In some embodiments, the thickness of the active layer is 120 nm.

[0080] In some embodiments, the active layer is subjected to a post-treatment after the formation of the active layer described above, wherein the post-treatment includes but is not limited to, a heat annealing treatment, a vacuum treatment, and a solvent annealing treatment.

[0081] In some embodiments, the annealing temperature of the heating anneal process is 25 °C - 150 °C (e.g., 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C, 125 °C, 130 °C, 135 °C, 140 °C, 145 °C, 150 °C, etc.), or 50 °C - 130 °C, and the annealing time is 1 min - 30 min (e.g., 1 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc.). In some embodiments, the annealing temperature is 120 °C. In some embodiments, the annealing time is 20 min.

[0082] In some embodiments, the transparent substrate can be composed of inorganic transparent materials, such as glass, quartz, etc., or organic materials, such as 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.

[0083] In some embodiments, 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, a combination of one or more materials selected from indium tin oxide (ITO), graphene thin film, silver nanowire thin film (Ag NW), silver nanoparticle mesh (Ag NP), carbon nanotube thin film (SWCNT), MXene, poly 3,4-ethylenedioxythiophene / poly(styrenesulfonate) (PSS:PEDOT). In some embodiments, the transparent electrode material is indium tin oxide.

[0084] In some embodiments, the electron transport layer is composed of N-type semiconductors with low work function, which can be organic or inorganic semiconductors. In some embodiments, the electron transport layer includes, but is not limited to, a combination of one or more materials of zinc oxide (ZnO), tin dioxide (SnO2), lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), potassium fluoride (KF), cesium carbonate ((Cs2CO3), 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthracenone[2,1,9-def:6,5,10-d'e'f']diisoquinoline (PDINN), N,N'-bis[3-(dimethylamino)propyl]perylene-3,4,9,10-tetracarboxydiimide (PDIN), N,N'-bis(N,N-dimethylpropane-1-oxylammonium)perylene-3,4,9,10-tetracarboxydiimide (PDINO), poly(9,9-bis(3'-(N,N-dimethyl)-N-ethylammonium propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)) dibromide (PFN-Br). In some embodiments, the hole transport layer is composed of organic or inorganic semiconductors with high work function. In some embodiments, the hole transport layer includes, but is not limited to, a combination of one or more materials of molybdenum oxide (MoOx, where x is a positive integer), nickel oxide (NiO), poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PSS:PEDOT). The thickness of each of the above-mentioned electron transport layer and hole transport layer independently ranges from 0.1 nm to 200 nm (e.g., 0.1 nm, 0.5 nm, 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 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, etc.).

[0085] In some embodiments, the electron transport layer is zinc oxide with a thickness of 50 nm, and the hole transport layer is molybdenum oxide with a thickness of 5 nm.

[0086] In some embodiments, the method of preparing the electron transport layer and hole transport layer includes, but is not limited to, spin-coating, printing, doctor blading, spray coating, evaporation, or a combination thereof. In some embodiments, the electron transport layer is prepared by solution spin-coating, and the hole transport layer is prepared by vacuum evaporation.

[0087] In some embodiments, the first electrode includes, but is not limited to, a metal thin film, a conductive polymer thin film, a metal oxide conductive thin film, or a combination thereof. In some embodiments, the first electrode includes, but is not limited to, gold (Au), silver (Ag), aluminum (Al), poly 3,4-ethylenedioxythiophene / polystyrene sulfonate (PSS:PEDOT), indium tin oxide (ITO), silver nanowire thin film (Ag NW), silver nanomesh (Ag NP), or a combination thereof. In some embodiments, the first electrode has a thickness ranging from 1-300 nm (e.g., 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 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, 300 nm, etc.), and in some embodiments, the first electrode has a thickness of 150 nm.

[0088] In some embodiments, the first electrode is a silver thin film.

[0089] In some embodiments, the first electrode is a top electrode.

[0090] In some embodiments, the method of preparing the first electrode includes, but is not limited to, evaporation, blade coating, screen printing, printing, physical etching, chemical etching, etc. In some embodiments, the method of preparing the first electrode is vacuum evaporation.

[0091] In some embodiments, the method of preparing the second electrode includes, but is not limited to, evaporation, blade coating, screen printing, printing, physical etching, chemical etching. In some embodiments, the method of preparing the second electrode is physical etching.

[0092] In another aspect, the present application provides a device comprising the photodetector described above.

[0093] 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, etc.

[0094] In some embodiments, the first electrode is a first array of strip electrodes, and the second electrode is a second array of strip electrodes. In some embodiments, the first array of strip electrodes is perpendicular to the second array of strip electrodes in a horizontal plane (e.g., the first array of strip electrodes is parallel to the second array of strip electrodes in a vertical plane). Figure 10, forming a crossbar electrode array). In some embodiments, the second array of strip electrodes is a micrometer-scale strip array.

[0095] In some embodiments, the first electrode is an anode and the second electrode is a cathode.

[0096] In some embodiments, the first array of strip electrodes has a line width dimension of 1 pm - 1 cm (e.g., 1 pm, 10 pm, 50 pm, 100 pm, 150 pm, 200 pm, 250 pm, 300 pm, 350 pm, 400 pm, 450 pm, 500 pm, 550 pm, 600 pm, 650 pm, 700 pm, 750 pm, 800 pm, 850 pm, 900 pm, 950 pm, 1000 pm, 2000 pm, 3000 pm, 4000 pm, 5000 pm, 6000 pm, 7000 pm, 8000 pm, 9000 pm, 1 cm, etc.). In some embodiments, the first array of strip electrodes has a line width pitch of 1 pm - 1 cm (e.g., 1 pm, 10 pm, 50 pm, 100 pm, 150 pm, 200 pm, 250 pm, 300 pm, 350 pm, 400 pm, 450 pm, 500 pm, 550 pm, 600 pm, 650 pm, 700 pm, 750 pm, 800 pm, 850 pm, 900 pm, 950 pm, 1000 pm, 2000 pm, 3000 pm, 4000 pm, 5000 pm, 6000 pm, 7000 pm, 8000 pm, 9000 pm, 1 cm, etc.).

[0097] In some embodiments, the second array of strip electrodes has a line width dimension of 1 pm - 1 cm (e.g., 1 pm, 10 pm, 50 pm, 100 pm, 150 pm, 200 pm, 250 pm, 300 pm, 350 pm, 400 pm, 450 pm, 500 pm, 550 pm, 600 pm, 650 pm, 700 pm, 750 pm, 800 pm, 850 pm, 900 pm, 950 pm, 1000 pm, 2000 pm, 3000 pm, 4000 pm, 5000 pm, 6000 pm, 7000 pm, 8000 pm, 9000 pm, 1 cm, etc.), or 10 pm - 500 pm.

[0098] In some embodiments, the line width pitch of the second array of strip electrodes is 1 pm - 1 cm (e.g., 1 pm, 10 pm, 50 pm, 100 pm, 150 pm, 200 pm, 250 pm, 300 pm, 350 pm, 400 pm, 450 pm, 500 pm, 550 pm, 600 pm, 650 pm, 700 pm, 750 pm, 800 pm, 850 pm, 900 pm, 950 pm, 1000 pm, 2000 pm, 3000 pm, 4000 pm, 5000 pm, 6000 pm, 7000 pm, 8000 pm, 9000 pm, 1 cm, etc.), or 10 pm - 500 pm.

[0099] In some embodiments, the line width dimension of the first array of strip electrodes and the second array of strip electrodes is 250 pm. In some embodiments, the line width pitch of the first array of strip electrodes and the second array of strip electrodes is 250 pm.

[0100] In another aspect, the application provides a compound of Formula I:

[0101]

[0102] wherein:

[0103] R 1 to R 6 each independently selected from C 2-12 alkyl.

[0104] In another aspect, the application provides a method of making a photodetector, comprising:

[0105] providing a first electrode;

[0106] providing a second electrode; and

[0107] disposing a photoactive layer between the first electrode and the second electrode,

[0108] wherein the photoactive layer comprises a compound of Formula I:

[0109]

[0110] wherein:

[0111] R 1 to R 6 each independently selected from C 2-12 alkyl.

[0112] In some embodiments, the method of preparation comprises: blending the electron donor material with the compound of Formula I to prepare an active layer structure, or obtaining a bilayer or multilayer structure by layer-by-layer preparation of an electron donor material thin film and an electron acceptor material thin film.

[0113] In some embodiments, the method of preparation comprises: blending the electron donor material with the compound of Formula I and optional additives in a solvent to obtain an active solution; using the active solution to form the photoactive layer.

[0114] In some embodiments, the method of preparation further comprises: forming the photoactive layer from the active solution by a method selected from spin coating, blade coating, printing, spraying, or a combination thereof.

[0115] In some embodiments, the method of preparation further comprises: post-treating the active layer after forming the active layer, wherein the post-treatment includes but is not limited to: heating annealing treatment, vacuumizing treatment, and solvent annealing treatment.

[0116] The present application provides one or more of the following advantages:

[0117] 1. The organic photodetector of the present disclosure can realize high sensitivity and rapid detection of different waveband light in the ultraviolet-visible-near infrared full spectrum range, and its active layer can effectively absorb light in the 300 nm-1050 nm waveband and realize efficient conversion of photons to electrons, achieving high sensitivity detection in the full spectrum.

[0118] 2. The specific detectivity of the organic photodetector of the present disclosure in the full spectrum range can almost reach 10 13 of the above order of magnitude.

[0119] 3. The organic photodetector of the present disclosure has high responsivity, which can achieve a maximum responsivity of more than 0.3 A / W in the near infrared region, and the responsivity is still more than 0.2 A / W when the wavelength reaches 1000 nm.

[0120] 4. The dark current of the organic photodetector of the present disclosure is at the level of nanampere or below under 0V and -1V bias.

[0121] 5. The organic photodetector of the present disclosure maintains the high response speed performance of organic photodetectors, and the response time can be less than 1 microsecond.

[0122] 6. The organic photodetector of the present disclosure has low noise (about 10 -14 -10 -15 A / Hz 1 / 2 ) characteristics.

[0123] 7. The organic photodetector structure of the present disclosure is simple, and the preparation method is flexible. Meanwhile, by designing the cathode and anode structures, the bottom electrode can be prepared into a strip array, and the top electrode can be prepared into a strip electrode array perpendicular to the bottom electrode. By using the vertical and horizontal intersection of the cathode and anode, a high-density organic photodetector array is obtained, and high-resolution imaging and identification of objects in the full spectral range are realized.

[0124] 8. The organic photodetector of the present disclosure has the advantages of flexibility, adjustable band gap, solution processing, low cost, etc. High-performance, low-cost, ultraviolet-visible-near-infrared full-spectrum organic photodetectors can be prepared by a solution method, and have great market and industrialization potential. It has great advantages in mass production of low-cost high-performance photodetectors.

[0125] Example

[0126] The specific embodiments of the present disclosure will be further described in detail below in combination with examples. The following examples are for illustrative purposes only, and are not intended to limit the scope of the present application.

[0127] Preparation Example 1

[0128] Scheme 1 shows the synthesis route of compound 1. Among them, compound A is synthesized according to the literature. Other chemicals are directly purchased and used without further purification.

[0129]

[0130] Scheme 1

[0131] The nuclear magnetic resonance hydrogen spectrum and mass spectrum of compound 1 are shown in Figure 11 and Figure 12 respectively.

[0132] Example 1:

[0133] The preparation method of the organic photodetector adopts a reverse structure, and the device structure is shown in Figure 1 , which includes a substrate (1), a transparent electrode (2), an electron transport layer (3), an active layer (4), a hole transport layer (5), and a top electrode (6).

[0134] The substrate is transparent glass, the transparent electrode is ITO, the electron transport layer is zinc oxide, the active layer material is a blend of PCE-10 and compound 1, the hole transport layer is MoO x , and the top electrode is a metal silver film evaporated.

[0135] The preparation method specifically includes the following steps:

[0136] S01. Clean the ITO-coated glass substrate with acetone, deionized water and isopropanol, and dry it with nitrogen, and place it in a clean petri dish for later use.

[0137] S02. Clean the ITO glass and treat it with ultraviolet ozone for 15 minutes to improve its surface hydrophilic properties.

[0138] S03. Dissolve 100 mg of zinc acetate in 10 ml of 2-methoxyethanol, and add 100 μg of ethanolamine to prepare a zinc oxide precursor solution, and spin-coat it on the clean ITO surface at a spin-coating speed of 2000 rpm for 40 s, and then move the glass substrate to the air and anneal it at 200°C for 1 h to obtain a uniform zinc oxide thin film as the electron transport layer.

[0139] S04. Spin-coat the interfacial layer material PFN-Br on the surface of the electron transport layer to reduce surface roughness, at a spin-coating speed of 3000 rpm for 50 s.

[0140] S05. Dissolve the organic donor material PCE-10 and compound 1 in a solvent chlorobenzene (CB) at a mass ratio of 1:1.5, and add DIO to obtain an active solution, wherein DIO accounts for 5% of the total mass of the active solution, and the total concentration of active materials in the active solution is 18 mg / ml, and spin-coat it on the surface of the PFN-Br interfacial layer at a spin-coating speed of 1000 rpm for 1 min. Then use a constant temperature hot stage to heat anneal at 120°C for 20 min, and the obtained active layer has a thickness of about 120 nm.

[0141] S06. Vacuum evaporate the hole transport layer MoOx on the surface of the active layer, at a pressure of 10- 4 Pa, and an evaporation thickness of 5 nm.

[0142] S07. Vacuum evaporate the metal anode Ag on the surface of the hole transport layer, at a pressure of 10 -4 Pa, and a thickness of 150 nm.

[0143] Example 2:

[0144] Prepare an organic photodetector with a forward structure, and the device structure is shown in Figure 2 , which includes a transparent substrate (1), a transparent electrode (2), a hole transport layer (3), an active layer (4), an electron transport layer (5), and a top electrode (6).

[0145] The transparent substrate is glass, the transparent electrode is ITO, the hole transport layer is PSS:PEDOT, the active layer material is a blend of PCE-10 and compound 1, the electron transport layer is PDINN, and the top electrode is silver.

[0146] The preparation method specifically comprises the following steps:

[0147] S01. Clean the glass substrate coated with ITO conductive layer with acetone, deionized water and isopropyl alcohol in sequence, and blow it dry with nitrogen, and place it in a clean culture dish for standby.

[0148] S02. Clean the ITO glass and perform ultraviolet ozone cleaning treatment for 15 minutes to improve the surface hydrophilic property.

[0149] S03. Spin-coat the PSS:PEDOT solution on the clean ITO surface at a spin-coating speed of 2000 rpm for 40 s, and then move the glass substrate to the air, and perform annealing treatment at 160°C for 1 h to obtain a uniform PSS:PEDOT thin film as a hole transport layer.

[0150] S04. Dissolve the organic donor material PCE-10 and the organic acceptor material compound 1 in the solvent chlorobenzene (CB) at a mass ratio of 1:1.5, and add DIO to obtain an active solution, wherein the DIO accounts for 5% of the total mass of the active solution, and the total concentration of the active material in the active solution is 18 mg / ml, spin-coat the active solution on the surface of the PFN-Br interfacial layer at a spin-coating speed of 1000 rpm and a time of 1 min. Then use a constant temperature hot stage to perform thermal annealing at 120°C for 20 min, and the obtained active layer has a thickness of about 120 nm.

[0151] S05. Dissolve 2 mg of PDINN in 10 ml of methanol to prepare a PDINN solution, and spin-coat the PDINN solution on the surface of the active layer as an electron transport layer at a spin-coating speed of 2000 rpm and a time of 1 min.

[0152] S06. Vacuum evaporate the metal anode Ag on the surface of the electron transport layer at a pressure of 10 -4 Pa and a thickness of 150 nm.

[0153] Example 3:

[0154] Based on the above results, a high-resolution ultraviolet-visible-near-infrared full-spectrum organic photodetector array is further prepared to realize high-resolution imaging and identification of objects.

[0155] The prepared high-resolution organic photodetector adopts a reverse structure, and the device structure is as shown in Figure 10 The device structure includes a transparent substrate (1), a transparent electrode (2), an electron transport layer (3), an active layer (4), a hole transport layer (5), and a top electrode (6).

[0156] The transparent substrate is PEN, the transparent electrode is ITO, the electron transport layer is zinc oxide, the active layer is a blend of PCE-10 and compound 1, the hole transport layer is MoO x , and the top electrode is silver (Ag).

[0157] The preparation method specifically comprises the following steps:

[0158] S01. A portion of the ITO conductive layer on the PEN substrate is removed by laser etching technology to obtain a strip-shaped ITO array with different line widths and spacings, and the PEN / ITO substrate is subjected to ozone treatment for 20 min.

[0159] S02. A methanol solution of ZnO nanoparticles with a concentration of 30 mg / ml -1 is spin-coated on a clean ITO surface at a spin speed of 4000 rpm for 20 s, and then annealed at 150°C for 20 min.

[0160] S03. The steps of preparing the active layer and the hole transport layer in Example 1 are repeated.

[0161] S04. A mask plate with a designed electrode array is covered on the device prepared in S03, and a top electrode is deposited, wherein the top electrode is an Ag film with a thickness of 150 nm.

[0162] The length of the transparent substrate (1) is 40 mm, and the width is 20 mm; the structure of the transparent electrode (2) is as shown in Figure 8 , and each PEN substrate has 50 strip-shaped ITO electrodes arranged longitudinally, each strip-shaped ITO electrode has a width of 250 μm, a spacing of 250 μm, and a length of 20 mm; the prepared top electrode array structure is as shown in Figure 9 , and each device has 50 strip-shaped silver electrodes arranged transversely, each strip-shaped silver electrode has a width of 250 μm, a spacing of 250 μm, and a length of 40 mm.

[0163] The array is realized by the longitudinal and transverse intersection of the cathode electrode and the anode electrode, and each substrate can contain 50×50=2500 single devices.

[0164] Comparative Example

[0165] An organic photodetector of the comparative example is prepared in the same manner as in Example 1, except that the following comparative compound is used instead of compound 1.

[0166]

[0167] Example 4:

[0168] The photoelectric performance of the UV-Vis-NIR full-spectrum organic photodetector obtained in the above examples and comparative examples was tested, mainly including:

[0169] 1) The spectral response of the reverse-structured organic photodetector prepared in the above example 1 was tested in a 25℃ environment, the test wavelength range was 300-1100nm, the test bias was 0V, and the spectral-response curve of the device was obtained, as shown in Figure 3 .

[0170] 2) The dark current density of the reverse-structured organic photodetector prepared in the above example 1 was tested in a 25℃ environment, the test bias range was -1V-1V, the interval between points was 10mV, and the reverse scan was performed, and the dark current density diagram of the device was obtained, as shown in Figure 4 .

[0171] 3) The specific detectivity of the organic photodetector at 0V bias in the wavelength range of 300-1100nm was calculated from the data obtained by 1) and 2), and the spectral-specific detectivity curve of the device was obtained, as shown in Figure 5A . The spectral-specific detectivity curve of the organic photodetector of the comparative example was obtained by the same method, as shown in Figure 5B .

[0172] 4) The response speed of the reverse-structured organic photodetector prepared in the above example 1 was tested in a 25℃ environment, the test laser was 700nm and 900nm respectively, and the test bias was 0V, and the response speed diagram of the device was obtained, as shown in Figure 6 and Figure 7 respectively.

[0173] Performance test results:

[0174] The organic photodetector in example 1 showed a responsivity of more than 0.3A / W in the near-infrared region (see Figure 3 ), and the responsivity at 1000nm was still more than 0.2A / W, which could meet the demand of near-infrared test.

[0175] The dark current density test results are shown in Figure 4 , the dark current density of the organic photodetector is as low as 10 - 10 A / cm 2 at 0V, and still has a dark current density as low as nanoscale at -1V, indicating that the organic photodetector effectively suppresses the dark current.

[0176] The specific detectivity of the organic photodetector at 0V is more than 10 13 Jones in the UV-Vis-NIR region (see Figure 5A), indicating that the organic photodetector of the present disclosure has obviously improved photoelectric performance in the whole response waveband relative to the organic photodetector of the comparative example (see Figure 5B ) in the whole response waveband.

[0177] The organic photodetector has response time curves (see Figure 6 ) under 700 nm visible light and response time curves (see Figure 7 ) under 900 nm near-infrared light, both of which show response and recovery times below 1 μs under 0 V bias.

[0178] The present disclosure has been described in detail with general description and specific embodiments above, 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 the present disclosure claimed.

Claims

1. A photodetector, comprising: a first electrode; a second electrode; and a photoactive layer disposed between the first electrode and the second electrode, wherein the photoactive layer comprises a compound of Formula I: Formula I wherein:

2. The photodetector of claim 1, wherein: R 1 to R 6 each independently selected from C 2-12 alkyl. the photodetector further comprises an electron transport layer and a hole transport layer disposed between the first electrode and the second electrode; or the photodetector further comprises a transparent substrate. the photodetector further comprises an electron transport layer and a hole transport layer disposed between the first electrode and the second electrode, the photoactive layer disposed between the electron transport layer and the hole transport layer.

3. The photodetector of claim 2, wherein, 4. The photodetector of any one of claims 1 to 3, wherein: the photodetector comprises a first electrode, a hole transport layer, a photoactive layer, an electron transport layer, a second electrode, and a transparent substrate disposed in that order; or the photodetector comprises a first electrode, an electron transport layer, a photoactive layer, a hole transport layer, a second electrode, and a transparent substrate disposed in that order; or 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 photoactive layer comprises the compound of Formula I as an electron acceptor material.

5. The photodetector of claim 4, wherein: the photoactive layer comprises the compound of Formula I as an electron acceptor material, the photoactive layer further comprising an electron donor material, wherein the electron donor material is selected from a material having a HOMO energy level higher than that of the electron acceptor material; or the photoactive layer further comprises an additive. the photoactive layer further comprises an electron donor material, the electron donor material being selected from PTB7-Th, poly(3-hexylthiophene-2,5-diyl), or any combination thereof.

6. The photodetector of claim 5, wherein, the photoactive layer comprises the compound of Formula I as an electron acceptor material, the photoactive layer further comprising an electron donor material, the mass ratio of the electron donor material to the electron acceptor material being 1:0.1-1:100, 1:0.5-1:5, or 1:1.

5.

7. The photodetector of claim 5, wherein, the photoactive layer further comprises an additive, the additive being selected from 1,8-diiodooctane, chloronaphthalene, nitrobenzene, or any combination thereof.

8. The photodetector of claim 5, wherein, the photoactive layer comprises the compound of Formula I as an electron acceptor material, the photoactive layer further comprising an electron donor material, the preparation of the photoactive layer comprising 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 a donor material thin film and an acceptor material thin film.

9. The photodetector of claim 5, wherein, the photoactive layer is a blended thin film structure.

10. The photodetector of claim 5, wherein, the photoactive layer comprises the compound of Formula I as an electron acceptor material, the photoactive layer further comprising an electron donor material, the preparation of the photoactive layer comprising a step of blending the electron donor material with the electron acceptor material in a solvent to obtain an active solution.

11. The photodetector of claim 5, wherein, ​ 12. The photodetector of claim 11, wherein, The preparation of the photo-sensing active layer comprises the step of blending the electron donor material and the electron acceptor material and an additive in a solvent to obtain an active solution.

13. The photodetector of claim 11, wherein, The solvent is selected from chloroform, a benzene ring-containing organic solvent, or a combination thereof.

14. The photodetector of claim 11, wherein, The solvent is selected from chlorobenzene, dichlorobenzene, toluene, or any combination thereof.

15. The photodetector of claim 11, wherein, The total concentration of both the electron donor material and the electron acceptor material in the active solution ranges from 0.01 mg / ml to 50 mg / ml, from 10 mg / ml to 30 mg / ml, or 18 mg / ml.

16. The photodetector of claim 12, wherein, The mass of the additive accounts for 0.01% to 50%, 0.05% to 10%, or 5% of the total mass of the active solution.

17. The photodetector of claim 4, wherein: The photodetector comprises a first electrode, a hole transport layer, a photo-sensing active layer, an electron transport layer, a second electrode, and a transparent substrate arranged in sequence; or the photodetector comprises a first electrode, an electron transport layer, a photo-sensing active layer, a hole transport layer, a second electrode, and a transparent substrate arranged in sequence; wherein the transparent substrate is selected from an inorganic transparent material or an organic material; or The second electrode is a transparent electrode; the transparent electrode is selected from a metal oxide, a metal thin film, an organic conductive material, a conductive nanomaterial, or any combination thereof; or The first electrode is selected from a metal thin film, a conductive polymer thin film, a metal oxide conductive thin film, or a combination thereof.

18. The photodetector of claim 17, wherein, The photodetector comprises a first electrode, a hole transport layer, a photo-sensing active layer, an electron transport layer, a second electrode, and a transparent substrate arranged in sequence; or the photodetector comprises a first electrode, an electron transport layer, a photo-sensing active layer, a hole transport layer, a second electrode, and a transparent substrate arranged in sequence; wherein the transparent substrate is selected from glass, quartz, polyethylene terephthalate, polyimide, polydimethylsiloxane, styrene-ethylene-butylene-styrene, polymethyl methacrylate, polyethylene 2,6-naphthalate.

19. The photodetector of claim 17, wherein, The second electrode is a transparent electrode, and the transparent electrode is selected from a combination of one or more materials selected from indium tin oxide, a graphene thin film, a silver nanowire thin film, a silver nanoparticle mesh, a carbon nanotube thin film, MXene, and poly 3,4-ethylenedioxythiophene / poly styrene sulfonate.

20. The photodetector of claim 17, wherein, The first electrode is selected from gold, silver, aluminum, poly 3,4-ethylenedioxythiophene / poly styrene sulfonate, indium tin oxide, a silver nanowire thin film, a silver mesh, or a combination thereof.

21. The photodetector of claim 17, wherein, The first electrode is a top electrode.

22. An apparatus comprising the photodetector of any one of claims 1 to 21.

23. The apparatus of claim 22, comprising an imaging recognition system, a wearable device, a robot, an implantable device, and a device for health monitoring, motion monitoring, obstacle detection.

24. The apparatus of claim 22 or 23, wherein: The apparatus is an imaging recognition system; and The first electrode is a first array of strip electrodes, and the second electrode is a second array of strip electrodes.

25. The apparatus of claim 24, wherein, The first array of strip electrodes is perpendicular to the second array of strip electrodes in a horizontal plane.

26. The apparatus of claim 24, wherein, The second array of strip electrodes is a microscale array of strip electrodes.

27. The apparatus of claim 24, wherein, The first electrode is an anode and the second electrode is a cathode.

28. The apparatus of claim 24, wherein, The line width dimension of the first array of strip electrodes and / or the second array of strip electrodes is 1 pm to 1 cm or 10 pm to 500 pm.

29. The apparatus of claim 24, wherein, The line width spacing of the first array of strip electrodes and / or the second array of strip electrodes is 1 pm to 1 cm or 10 pm to 500 pm.

30. The apparatus of claim 24, wherein, The line width dimension of the first array of strip electrodes and the second array of strip electrodes is 250 pm.

31. The apparatus of claim 24, wherein, The line width spacing of the first array of strip electrodes and the second array of strip electrodes is 250 pm.

32. A compound of formula I: Formula I wherein: R 1 to R 6 each independently selected from C 2-12 alkyl.

33. A method of making a photodetector comprising: providing a first electrode; providing a second electrode; and providing a photoactive layer between the first electrode and the second electrode, wherein the photoactive layer comprises a compound of formula I: Formula I wherein: R 1 to R 6 each independently selected from C 2-12 alkyl.

34. The photodetector of claim 1, the apparatus of claim 22 or 23, the compound of formula I of claim 32, or the method of claim 33, wherein: R in formula I 1 to R 6 each independently selected from C 4-12 alkyl; or R in formula I 1 to R 6 each independently selected from C 6-12 alkyl; or the compound of formula I is selected from: Compound 1.

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