A method for reducing leakage current in an organic photodiode device

Abstract

The present application relates to the technical field of organic optoelectronics, and provides a method for reducing the leakage current of an organic photodiode device. The present application can significantly reduce the leakage current of an organic photodiode device by preparing a functional layer through a multiple solution deposition method. The leakage current of the device is related to the number of solution deposition of the functional layer, and the leakage current of the device continuously decreases with the increase of the number of solution deposition, and finally reaches a saturation value. When the total thickness of multiple solution deposition is consistent with the thickness of single solution deposition, the leakage current of the device formed by multiple solution deposition is significantly lower than that of the device prepared by single solution deposition. The method provided by the present application is suitable for a wide range of functional layer material systems and is suitable for various device structures, has good universality, is widely applicable, and can greatly promote the industrialization process of the organic photodiode device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic optoelectronics, and in particular to a method for reducing the leakage current of an organic photodiode device. BACKGROUND

[0002] Since the discovery of organic semiconductor materials, they have attracted much attention due to their low cost, wide availability, light weight, easy processing, and tunable optoelectronic properties. However, due to the poor optoelectronic performance (such as photoelectric conversion efficiency and mobility) of early organic semiconductor materials, related research has only remained at the laboratory stage. With the continuous progress of technology, significant improvements have been made in the design of molecular structures and synthesis processes of materials, which has led to the continuous development of organic semiconductor materials over the past 20 years. Currently, they have been applied in organic photodiode devices such as organic thin film transistors (OFET), light-emitting diodes (OLED), solar cells (OSC), sensors (OPD), and photorefractive (PR) (Chem. Rev. 2016, 116, 22, 13279-13412).

[0003] Currently, the scientific community generally believes that organic optoelectronics has reached the "dawn of industrialization". The main methods for preparing functional layers of organic diode devices in industrialization include slot die coating, inkjet printing, spin coating, and doctor blade coating. The bottleneck of the industrialization development of solution deposition process for preparing organic photodiode devices is how to solve the problem of excessive leakage current of the device. Reducing the leakage current of organic photodiode devices is the primary goal of solution deposition process industrialization research and is also the key to achieving industrialization.

[0004] Related researchers have improved the molecular crystallinity in the functional layer system through solution gas phase deposition method, thereby effectively reducing the leakage current of the device (ACS Appl. Mater. Interfaces 2021, 13, 44604-44614). However, this method can only reduce the leakage current of diode devices based on specific functional layer systems and does not have universality, so it cannot be widely applied in the industrialization process of organic photodiode devices. SUMMARY

[0005] Therefore, the present application provides a method for reducing the leakage current of an organic photodiode device. The method provided by the present application can effectively reduce the leakage current of an organic photodiode device and has universality, which can greatly promote the industrialization process of organic photodiode devices.

[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0007] A method for reducing the leakage current of an organic photodiode device, which uses a functional layer material as a raw material to prepare a functional layer by a solution deposition method for multiple times; the number of solution deposition is more than 2 times.

[0008] Preferably, the functional layer of the organic photodiode device is a heterojunction system.

[0009] Preferably, the functional layer material includes one or more of an organic semiconductor donor / fullerene acceptor system and an organic semiconductor donor / non-fullerene acceptor system.

[0010] Preferably, the organic semiconductor donor / fullerene acceptor system is PTB7-Th:PC71BM; and the organic semiconductor donor / non-fullerene acceptor system is PM6:Y6.

[0011] Preferably, the solution deposition method includes: spin coating an organic solution of the functional layer material on the surface of a substrate.

[0012] Preferably, the number of solution deposition is 2-30 times.

[0013] Preferably, the concentration of the organic solution of the functional layer material is greater than 0 and less than or equal to 40 mg / mL.

[0014] Preferably, the spin coating speed is 500-8000 rpm.

[0015] Preferably, the organic photodiode device includes one of an organic photovoltaic device, an organic solar cell, an organic photodetector, an organic light-emitting diode, and an organic field effect transistor.

[0016] Preferably, the structure of the organic photodiode device is a normal structure, a flip-chip structure, or an inverted structure.

[0017] The application provides a method for reducing the leakage current of an organic photodiode device, which uses a functional layer material as a raw material and prepares the functional layer through a multiple solution deposition method; the number of solution deposition is more than 2 times. The inventor finds that the leakage current of the device is related to the number of solution deposition of the functional layer, and the leakage current of the device decreases continuously with the increase of the number of solution deposition, and finally reaches a saturation value; when the total thickness of multiple solution deposition is consistent with the thickness of single solution deposition, the leakage current of the device formed through multiple solution deposition is obviously lower than that of the device prepared through single solution deposition. Based on the above finding, the application provides a method for reducing the leakage current of an organic photodiode device by preparing a functional layer through multiple solution deposition. The method provided by the application is suitable for a wide range of functional layer material systems, including an organic semiconductor donor / fullerene acceptor system and an organic semiconductor donor / non-fullerene acceptor system; the device structure is suitable for a positive installation, a reverse installation, a reverse installation, an organic photovoltaic device (OPV), an organic light-emitting diode (OLED), an organic photodetector (OPD) and an organic field effect transistor (OFET) and other photodiode devices of a traditional bulk heterojunction structure. Therefore, the method provided by the application has good universality, is widely used and easy to operate, and can greatly promote the industrialization process of the organic photodiode device.

[0018] Further, the method provided by the application is simple in operation and easy to control when preparing the functional layer, and the thickness of the functional layer depends on the concentration of the solution used in multiple solution deposition, the spin coating speed and the number of deposition. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a device structure schematic diagram of the positive installation structure in the application;

[0020] Figure 2 It is the J-V curve of the device with the functional layer of PTB7-Th:PC71BM (fullerene system) in Example 1;

[0021] Figure 3 It is the J-V curve of the device with the functional layer of PM6:Y6 (non-fullerene system) in Example 1;

[0022] Figure 4 It is a device structure schematic diagram of the reverse installation structure in the application;

[0023] Figure 5 It is the J-V curve of the device with the functional layer of PTB7-Th:PC71BM (fullerene system) in Example 2;

[0024] Figure 6 It is the J-V curve of the device with the functional layer of PM6:Y6 (non-fullerene system) in Example 2;

[0025] Figure 7A device structure schematic diagram of the reverse structure in the application;

[0026] Figure 8 A J-V curve of the device in Example 3 with the functional layer of PTB7-Th:PC71BM (fullerene system).

[0027] Figure 9 A J-V curve of the device in Example 3 with the functional layer of PM6:Y6 (non-fullerene system). DETAILED DESCRIPTION

[0028] The application provides a method for reducing the leakage current of an organic photodiode device, which uses a functional layer material as raw material and prepares the functional layer through a solution deposition method for multiple times.

[0029] In the application, the organic photodiode device preferably comprises one of an organic photovoltaic device (OPV), an organic solar cell (OSC), an organic photodetector (OPD), an organic light-emitting diode (OLED) and an organic field effect transistor (OFED).

[0030] In the application, the structure of the organic photodiode device is preferably a normal structure, a flip structure or a reverse structure; in the application, the normal structure comprises, from bottom to top, a substrate, an anode, an anode interface layer, a functional layer, a cathode interface layer and a cathode, wherein the cathode is a reflective electrode; the flip structure comprises, from bottom to top, a substrate, a cathode, a cathode interface layer, a functional layer, an anode interface layer and an anode, wherein the anode is a reflective electrode; and the reverse structure comprises, from bottom to top, a substrate, a cathode, a cathode interface layer, a functional layer, an anode interface layer and an anode, wherein the cathode is a reflective electrode.

[0031] The present application does not have special requirements for the types, thicknesses and preparation methods of the base glass, anode, anode interface layer, cathode interface layer and cathode in the forward structure, flip structure or reverse structure, and any method known to those skilled in the art can be used. In specific embodiments of the present application, the base in the forward structure is preferably a glass substrate, the anode is preferably ITO, the anode interface layer is preferably PEDOT:PASS (poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid), the cathode interface layer is preferably PFN-Br, and the cathode is preferably an Ag electrode; the base in the flip structure is preferably a glass substrate, the cathode is preferably ITO, the cathode interface layer is preferably ZnO, the anode interface layer is preferably MoO3, and the anode is preferably an Ag electrode; the base in the reverse structure is preferably a glass substrate, the cathode is preferably a Ti-Al-Ti composite metal electrode, the cathode interface layer is preferably PFN-Br, the anode interface layer is preferably MoO3, and the anode is preferably an Au-Ag composite electrode, wherein the thickness of the Au layer in the Au-Ag composite electrode is preferably 1 nm, and the thickness of the Ag layer is preferably 6 nm.

[0032] In the present application, the functional layer of the organic photodiode device is preferably a heterojunction system; specifically, the functional layer material preferably includes one or more of an organic semiconductor donor / fullerene acceptor system and an organic semiconductor donor / non-fullerene acceptor system; the organic semiconductor donor / fullerene acceptor system is preferably PTB7-Th:PC71BM, wherein the mass ratio of PTB7-Th and PC71BM is preferably 1:1; and the organic semiconductor donor / non-fullerene acceptor system is preferably PM6:Y6, wherein the mass ratio of PM6 and Y6 is preferably 1:1.2.

[0033] In the present application, the solution deposition method preferably includes spin coating the functional layer material organic solution on the surface of the substrate; the number of solution deposition is preferably 2-30 times (i.e. spin coating the functional layer material organic solution 2-30 times), more preferably 3-25 times, and further preferably 5-10 times; the functional layer material organic solution is preferably obtained by dissolving the functional layer material in an organic solvent, and the organic solvent is preferably chlorobenzene or chloroform; in specific embodiments of the present application, when the functional layer material is PTB7-Th:PC71BM, the organic solvent is preferably chlorobenzene, and when the functional layer material is PM6:Y6, the organic solvent is preferably chloroform.

[0034] In the present application, the concentration of the functional layer material organic solution is preferably greater than 0 and less than or equal to 40 mg / mL, more preferably 1-30 mg / mL, and further preferably 5-15 mg / mL. In specific embodiments of the present application, when the functional layer material is PTB7-Th:PC71BM, the concentration of the functional layer material organic solution is preferably 10 mg / mL, and when the functional layer material is PM6:Y6, the concentration of the functional layer material organic solution is preferably 8 mg / mL.

[0035] In the present application, the spin coating speed is preferably 500-8000 rpm, more preferably 1000-7000 rpm, and further preferably 2000-4000 rpm. In the present application, the thickness of the functional layer depends on the number of solution depositions, the concentration of the functional layer material organic solution, and the spin coating speed. The greater the number of solution depositions, the greater the concentration of the functional layer organic solution, or the slower the spin coating speed, the greater the thickness of the functional layer, and vice versa. The leakage current of the organic photodiode device is related to the number of solution depositions of the functional layer. As the number of depositions increases, the device leakage current continuously decreases until it reaches a saturation value. In specific embodiments of the present application, the total thickness of the functional layer is preferably 80-200 nm, and the thickness of each solution deposition is preferably 25-40 nm.

[0036] In specific embodiments of the present application, an ITO glass substrate is preferably used, and each layer is prepared in sequence on the ITO glass substrate. Before use, the ITO glass substrate is preferably subjected to pretreatment, which preferably includes ultrasonic treatment of the ITO glass substrate in a pure water solution of detergent, followed by washing with ultrapure water until no foam is generated, then heating treatment in an ultrapure water-hydrogen peroxide-ammonia mixed solution, and finally blowing dry with nitrogen. The present application does not have special requirements for the type of detergent, and any detergent with cleaning ability known to those skilled in the art can be used. The ultrasonic treatment time is preferably 15 min. The volume ratio of ultrapure water, hydrogen peroxide (concentration 30 wt%), and ammonia (concentration 25 wt%) in the ultrapure water-hydrogen peroxide-ammonia mixed solution is preferably 5:1:1. The heating treatment temperature is preferably 85℃, and the time is preferably 40 min. The present application removes organic impurities on the substrate by heating treatment.

[0037] In the specific embodiments of the present application, when the device structure is a forward structure, preferably, the anode interface layer is prepared on the surface of the ITO glass substrate first, then the functional layer is prepared on the surface of the anode interface layer by using the multiple solution deposition method, and then the cathode interface layer and the cathode are prepared in sequence; the preparation method of the anode interface layer is preferably as follows: the solution of the anode interface layer material is dropped on the surface of the substrate, and after spin coating into a film, annealing is performed; the annealing temperature is preferably determined according to the anode interface layer material; when the anode interface layer is PEDOT:PASS, the annealing temperature is preferably 150°C, and the time is preferably 20 min; when the cathode interface layer is PFN-Br, the preparation method of the cathode interface layer is preferably spin coating method; and the preparation method of the cathode is preferably evaporation method.

[0038] In the specific embodiments of the present application, when the device structure is a flip structure, preferably, the cathode interface layer is prepared on the surface of the ITO glass first, then the functional layer is prepared on the surface of the cathode interface layer by using the multiple solution deposition method, and then the anode interface layer and the anode are prepared in sequence; when the cathode interface layer is a ZnO layer, the preparation method of the cathode interface layer is preferably as follows: the ZnO solution is dropped on the substrate, then spin coated into a film, and then annealed at 200°C for 30 min; when the anode interface layer is MoO3, the preparation method of the anode interface layer is preferably evaporation method.

[0039] In the specific embodiments of the present application, when the device structure is a reverse structure, preferably, the cathode and the cathode interface layer are prepared on the surface of the ITO glass first, then the functional layer is prepared on the surface of the cathode interface layer by using the multiple solution deposition method, and then the anode interface layer and the anode are prepared in sequence; the preparation methods of the cathode and the anode are both preferably evaporation method; when the cathode interface layer is PFN-Br, the preparation method of the cathode interface layer is preferably spin coating method; when the anode interface layer is MoO3, the preparation method of the anode interface layer is preferably evaporation method.

[0040] The technical solutions in the present application will be described clearly and completely in combination with the embodiments in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0041] Embodiment 1

[0042] Preparation of the forward device, the device structure is as shown in Figure 1 The preparation steps are as follows:

[0043] (1) Put ITO glass substrate into detergent pure water solution, ultrasonic for 15 minutes, then rinse the substrate with ultrapure water until no foam, then use TL-1 (mixed solution of ultrapure water: hydrogen peroxide: ammonia water with volume ratio of 5:1:1) to heat at 85℃ for 40 minutes to remove organic impurities on the substrate. Finally, the cleaned substrate is blown dry with nitrogen for standby (cleaning of the substrate surface).

[0044] (2) Take PEDOT:PSS 4083, filter treatment for standby, and prepare 0.5mg / mL PFN-Br methanol solution for standby.

[0045] (3) Put the ITO glass substrate on the spin coater, and use a pipette to drop 60μL of filtered PEDOT:PSS 4083 liquid on the substrate, and spin at 5000rpm for 1 minute to form a film.

[0046] (4) After spin coating, move the substrate with PEDOT:PSS 4083 thin film to the heating stage, and anneal at 150℃ for 20min.

[0047] (5) Put the annealed substrate on the spin coater again, and prepare the functional layer by multiple solution deposition method, and the functional layer materials used are PM6:Y6 and PTB7-Th:PC 71 BM respectively, and set a reference group, which uses single solution deposition method to prepare the functional layer, and the specific steps are as follows:

[0048] Reference group: spin 16mg / mL PM6:Y6 chloroform solution and 22mg / mL PTB7-Th:PC 71 BM chlorobenzene solution at 3000rpm for single spin, to obtain PM6:Y6 film and PTB7-Th:PC 71 BM film respectively, and the thickness of the two functional layers is 110nm.

[0049] Experimental group: spin 8mg / mL PM6:Y6 chloroform solution and 10mg / mL PTB7-Th:PC 71 BM chlorobenzene solution at 3000rpm for multiple spin, to obtain functional layers with different spin times. For PM6:Y6 system, the thickness of the functional layer is 32nm, 55nm, 74nm, 99nm and 110nm respectively when the spin times are 1, 2, 3, 4 and 5 times; for PTB7-Th:PC 71 BM system, the thickness of the functional layer is 27nm, 49nm, 67nm, 85nm and 110nm respectively when the spin times are 1, 2, 3, 4 and 5 times.

[0050] (6) After the functional layer is spin-coated, the isopropanol solution of PFN-Br is spin-coated on the substrate at a rotation speed of 3000 rpm for 40 seconds, and then the substrate is transferred into a vacuum evaporation chamber to evaporate a 100 nm Ag electrode, thereby completing the preparation of the organic photodiode device.

[0051] The prepared device is transferred out of the vacuum evaporation chamber, and then a current density-voltage (J-V) curve test is performed. The results are shown in FIG. 2, wherein Figures 2-3 Figure 2 is the J-V curve of the device with the functional layer being PTB7-Th:PC71BM (fullerene system), Figure 3 is the J-V curve of the device with the functional layer being PM6:Y6 (non-fullerene system).

[0052] It can be seen from the analysis of the measured J-V curve that, from the reference group device to the device prepared by the multiple spin-coating process, when the functional layer thickness is consistent, at an applied bias of -0.5 V, the dark current of the PTB7-Th:PC 71 BM device is reduced from 6.9 x 10 -2 mA / cm 2 to 3.3 x 10 -6 mA / cm 2 , and the dark current of the PM6:Y6 device based on the non-fullerene system is reduced from 5.0 x 10 -4 mA / cm 2 to 5.5 x 10 -7 mA / cm 2 . When the spin-coating times are less, the dark current is higher than that of the reference group due to the thin film thickness.

[0053] Example 2

[0054] Preparation of an inverted device, the device structure is shown in FIG. 3, and the preparation steps are as follows: Figure 4

[0055] (1) The ITO glass substrate is added to a pure water solution of detergent and ultrasonically treated for 15 minutes, and then the substrate is washed with ultrapure water until no foam is generated. Then, TL-1 (a mixed solution of ultrapure water, hydrogen peroxide and ammonia water in a volume ratio of 5:1:1) is used to heat at 85°C for 40 minutes to remove organic impurities on the substrate. Finally, the cleaned substrate is dried with nitrogen for standby (cleaning of the substrate surface).

[0056] (2) A ZnO solution is prepared with a concentration of 0.45 mol / L for standby.

[0057] (3) The ITO glass substrate is placed on a spin coater, and 60 μL of the ZnO solution is dropped on the substrate using a pipette gun and spin-coated uniformly at 4000 rpm.

[0058] ​​(4) After spin coating, transfer to the heating table, 200℃ annealing for 30min.

[0059] (5) Put the annealed substrate on the spin coater again, prepare the functional layer by multiple solution deposition method, and the functional layer materials used are PM6:Y6 and PTB7-Th:PC 71 BM respectively. Set a reference group, which uses a single solution deposition method to prepare the functional layer. The specific steps are as follows:

[0060] Reference group: single spin coating of 16mg / mL PM6:Y6 chloroform solution and 22mg / mL PTB7-Th:PC 71 BM chlorobenzene solution at a speed of 3000rpm to obtain PM6:Y6 and PTB7-Th:PC 71 BM films, and the thickness of the two functional layers is 110nm.

[0061] Experimental group: multiple spin coating of 8mg / mL PM6:Y6 chloroform solution and 10mg / mL PTB7-Th:PC 71 BM chlorobenzene solution at a speed of 3000rpm to obtain functional layers of different spin coating times. For the PM6:Y6 system, the functional layer thicknesses corresponding to spin coating times of 1, 2, 3, 4 and 5 times are 39nm, 60nm, 87nm, 100nm and 110nm respectively; while for the PTB7-Th:PC 71 BM system, the functional layer thicknesses corresponding to spin coating times of 1, 2, 3, 4 and 5 times are 36nm, 57nm, 75nm, 93nm and 110nm respectively.

[0062] (6) Then transfer the substrate into the vacuum evaporation chamber, evaporate 10nm MoO3 and 100nm Ag electrode to complete the preparation of the organic photodiode device.

[0063] The prepared device is transferred out of the vacuum evaporation chamber, and then the current density-voltage (J-V) curve test is carried out. The results are shown in Figures 5-6 , wherein Figure 5 is the J-V curve of the device with PTB7-Th:PC71BM (fullerene system) as the functional layer, Figure 6 is the J-V curve of the device with PM6:Y6 (non-fullerene system) as the functional layer.

[0064] According to Figures 5-6 It can be seen that when the functional layer thickness of the multiple spin coating device in the dark environment is consistent with the reference group, the applied bias voltage is-0.5V, and the dark current of the fullerene system decreases from 0.005mA / cm 2 to 9.02×10 -6 mA / cm2 , the non-fullerene system dark current decreased from 0.0112 mA / cm 2 to 8.10 x 10 -7 mA / cm 2 , the dark current was higher than the reference group due to the thin film thickness when the spin-coating times were less.

[0065] Example 3

[0066] The preparation of the inverted device, the device structure is shown as Figure 7 , the preparation steps are as follows:

[0067] (1) Put the ITO glass substrate into a detergent pure water solution, ultrasonic for 15 minutes, then wash the substrate with ultrapure water until no foam, then use TL-1 (a mixed solution of ultrapure water, hydrogen peroxide and ammonia water with a volume ratio of 5:1:1) at 85°C for 40 minutes to remove organic impurities on the substrate. Finally, the cleaned substrate is blown dry with nitrogen for standby (cleaning of the substrate surface).

[0068] (2) Prepare a 0.5 mg / mL PFN-Br methanol solution for standby.

[0069] (3) Put the cleaned transparent glass into the evaporation chamber, and evaporate 100 nm of Ti-Al-Ti composite metal electrode.

[0070] (4) Put the substrate with metal electrode evaporated into the spin coater, use the pipette to drop 50 μL PFN-Br on the substrate, spin the PFN-Br isopropanol solution at a speed of 3000 rpm for 40 seconds.

[0071] (5) Put the substrate again into the spin coater, prepare the functional layer by multiple solution deposition method, and the functional layer materials used are PM6:Y6 and PTB7-Th:PC 71 BM respectively, and set a reference group, the reference group uses a single solution deposition method to prepare the functional layer, the specific steps are as follows:

[0072] Reference group: spin 16 mg / mL PM6:Y6 chloroform solution and 22 mg / mL PTB7-Th:PC 71 BM chlorobenzene solution at a speed of 3000 rpm for single spin, respectively, to obtain PM6:Y6 thin film and PTB7-Th:PC 71 BM thin film, the thickness of the two functional layers is 105 nm;

[0073] Experimental group: spin 8 mg / mL PM6:Y6 chloroform solution and 10 mg / mL PTB7-Th:PC 71BM chlorobenzene solution, to obtain functional layers with different spin-coating times. Among them, for the PM6:Y6 system, the functional layer thicknesses corresponding to spin-coating times of 1, 2, 3, 4 and 5 times are 30 nm, 55 nm, 70 nm, 89 nm and 105 nm, respectively; while for the PTB7-Th:PC 71 BM system, the functional layer thicknesses corresponding to spin-coating times of 1, 2, 3, 4 and 5 times are 36 nm, 57 nm, 75 nm, 93 nm and 105 nm, respectively.

[0074] (6) Subsequently, the substrate is transferred into a vacuum evaporation chamber, 10 nm of M0O3, 1 nm of Au and 6 nm of Ag are evaporated, and the preparation of the organic photodiode device is completed.

[0075] The prepared device is transferred out of the vacuum evaporation chamber, and then tested for current density-voltage (J-V) curves. The results are shown in FIG. 2, wherein Figures 8-9 FIG. 2 is a J-V curve of the device with a functional layer of PTB7-Th:PC71BM (fullerene system), Figure 8 FIG. 2 is a J-V curve of the device with a functional layer of PTB7-Th:PC71BM (fullerene system), Figure 9 FIG. 2 is a J-V curve of the device with a functional layer of PTB7-Th:PC71BM (fullerene system),

[0076] According to Figures 8-9 It can be seen that when the thickness of the functional layer of the device with multiple spin-coating times is consistent with that of the reference group in a dark environment, the dark current of the fullerene system decreases from 8.33 x 10 -4 mA / cm 2 to 1.10 x 10 -6 mA / cm 2 , and the dark current of the non-fullerene system decreases from 1.06 x 10 -1 mA / cm 2 to 1.61 x 10 -6 mA / cm 2 , and the dark current is higher than that of the reference group when the spin-coating times are less due to the thin film thickness.

[0077] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A method for reducing leakage current in organic photodiode devices, characterized in that, The functional layer is prepared by using a functional layer material as raw material and through a multiple solution deposition method; the number of solution depositions is 2 to 30; the functional layer material includes one or more of an organic semiconductor donor / fullerene acceptor system and an organic semiconductor donor / non-fullerene acceptor system; The solution deposition method includes: spin-coating an organic solution of the functional layer material onto a substrate surface; The concentration of the organic solution of the functional layer material is greater than 0 and less than or equal to 40 mg / mL; the spin coating speed is 500~8000 rpm.

2. The method according to claim 1, characterized in that, The functional layer of the organic photodiode device is a heterojunction system.

3. The method according to claim 1, characterized in that, The organic semiconductor donor / fullerene acceptor system is PTB7-Th:PC71BM; the organic semiconductor donor / non-fullerene acceptor system is PM6:Y6.

4. The method according to claim 1, characterized in that, The organic photodiode device includes one of organic photovoltaic devices, organic solar cells, organic photodetectors, organic light-emitting diodes, and organic field-effect transistors.

5. The method according to claim 1 or 4, characterized in that, The organic photodiode device has a normal, inverted, or reversed structure.

Images