Diode type event sensor and preparation method and application thereof

Abstract

The invention belongs to the technical field of photoelectric detection, and discloses a diode type event sensor and a preparation method and application thereof. The sensor comprises a substrate, a bottom electrode, an electron transport layer, an acceptor layer, a donor layer, an electrode modification layer and a top electrode which are sequentially connected from bottom to top. The bottom electrode and the top electrode are perpendicular to each other to form a cross array. The event sensor provided by the invention detects the change of light intensity and generates voltage or current pulse. The voltage and current directions are positive when the light intensity is increased, the voltage and current directions are negative when the light intensity is reduced, and the voltage and current peak values are positively correlated with the light intensity change amplitude. According to the invention, event-based photoelectric detection is realized by using a device with a single diode structure, and the device can be applied to novel cameras and machine vision systems.

Description

[0001] Inventors: Huang Hui, Lin Qijie

[0002] Applicant: University of Chinese Academy of Sciences Technical Field

[0003] The present invention belongs to the technical field of optoelectronic detection, and particularly relates to a diode-type event sensor, a preparation method thereof, and an application thereof. Background Art

[0004] Machine vision technology enables machines to have the ability to perceive the environment and respond, which is very important in automation technology. With the development of Industry 4.0, intelligent robots, and autonomous driving technology, the annual output of optical sensors has reached 8.1 billion, and both the time and space resolutions are continuously increasing. However, traditional frame-based optical sensors collect a large amount of redundant data, and transmitting and processing this data requires a large amount of time and energy, which limits the response speed and battery life of robots. Different from traditional cameras, event-based sensors mimic the light detection mechanism of the human eye, only detect changes in light signals, can eliminate redundant data between frames, and have a larger light intensity response range and higher time resolution. Current event sensors need to integrate an electronic circuit next to each photodiode, and achieve event-based sensing through circuits such as differentiators and comparators, resulting in low sensor integration density, high power consumption, and the highest resolution being only 1 / 100 of that of traditional civilian optical sensors. Moreover, these event sensors can only output two types of event signals, positive and negative. Implementing an event sensor with a simple structure and small size is of great significance for improving the response speed and energy efficiency of machine vision systems, and can promote the development of fields such as the Internet of Things, drones, and autonomous driving. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a diode-type event sensor, a preparation method thereof, and an application thereof.

[0006] The technical solution adopted by the present invention to solve its technical problems is:

[0007] A diode-type event sensor, the sensor includes a substrate, a bottom electrode, an electron transport layer, a receptor layer, a donor layer, an electrode modification layer, and a top electrode that are sequentially connected from bottom to top.

[0008] Further, a transparent bottom electrode formed on the substrate, an electron transport layer formed on the bottom electrode, an electron acceptor formed on the electron transport layer, an electron donor doped with a P-type dopant formed on the acceptor, an electrode modification layer formed on the donor, and a top electrode formed on the electrode modification layer.

[0009] Further, the substrate material is selected from a glass sheet, a PET plastic film, or a PI plastic film;

[0010] Alternatively, the transparent bottom electrode is selected from any one or a combination of indium tin oxide (ITO) glass, fluorine-doped tin dioxide (FTO) glass, and aluminum-doped zinc oxide (AZO) glass; the thickness of the bottom electrode is 80 - 150 nm;

[0011] Alternatively, the electron transport layer is selected from any one or a combination of zinc oxide, tin dioxide, PFN, PFN-Br, PEI, and PEIE; the material concentration is 80 - 120 mg / mL;

[0012] Alternatively, the material of the acceptor layer is selected from any one or a combination of N2200, Y6, ITIC, and PC60BM; the material concentration is 8 - 15 mg / mL;

[0013] The structural formula of the above-mentioned compound is as follows:

[0014]

[0015]

[0016] Further, the material of the donor layer is selected from any one or a combination of PM6, D18, PBDB-T, J52, P3HT, and PTB7-Th, and any one or a combination of BCF, BF3, F4TCNQ, and iodine vapor is added as a dopant; the concentration of the donor layer material is 5 - 10 mg / mL, and the addition amount of the dopant is 5 - 20% of the mass of the donor layer;

[0017] The structural formula of the above-mentioned compound is as follows:

[0018]

[0019]

[0020] Further, the electrode modification layer is selected from any one or a combination of LiF, PFN, PFN-Br, BCP, PEI, and PEIE; the thickness of the electrode modification layer is 5 - 15 nm;

[0021] The structural formula of the above-mentioned compound is as follows:

[0022]

[0023] Further, the electrode modification layer is selected from materials that can reduce the work function of the top electrode or reduce interface defects.

[0024] Alternatively, the top electrode material is selected from any one or a combination of calcium, magnesium, aluminum, and ytterbium;

[0025] Alternatively, the top electrode material is selected from a conductive material with a work function less than 4 eV or a conductive material with a work function less than 4 eV after combination with the electrode modification layer;

[0026] Alternatively, the thickness of the top electrode is 50 - 100 nm.

[0027] Furthermore, both the bottom electrode and the top electrode are strip-shaped, perpendicular to each other, forming a cross electrode array, and each intersection point is a sensor pixel. The donor and the acceptor form a P-N junction, and a photo-generated voltage of 0 V - 0.8 V can be generated under illumination. The donor forms a Schottky contact with the top electrode, having an interfacial barrier greater than 0.5 eV.

[0028] Furthermore, it includes the following steps:

[0029] (1) Deposit a bottom electrode on a clean substrate material by magnetron sputtering or spin coating method;

[0030] (2) Spin coat or scrape coat an electron transport layer on the bottom electrode, and its solvent is any one or a combination of ethanol, methanol, water, and 2-methoxyethanol;

[0031] (3) Spin coat or scrape coat an acceptor layer on the electron transport layer, and its solvent is one or a combination of chloroform, toluene, and chlorobenzene;

[0032] (4) Spin coat or scrape coat a donor layer on the acceptor layer, and its solvent is one or a combination of chloroform, carbon disulfide, and tetrahydrofuran, and its solubility is orthogonal to the acceptor solvent and will not damage the acceptor layer;

[0033] (5) Spin coat or vacuum deposit an electrode modification layer on the donor layer, and the spin coating solvent is any one or a combination of ethanol, methanol, water, and 2-methoxyethanol;

[0034] (6) Vacuum deposit a top electrode on the electrode modification layer.

[0035] Application of the event sensor as described above in the Internet of Things and / or new cameras.

[0036] Application of the event sensor as described above in a machine vision system.

[0037] The advantages and positive effects achieved by the present invention are:

[0038] 1. The present invention can achieve event-based photoelectric detection with only a single device. A sensor pixel consists of a single diode, and an array can be formed with cross electrodes to achieve high-resolution imaging.

[0039] 2. When the light intensity changes, the sensor of the present invention generates voltage or current pulse signals. The response speed can reach 0.2 ms, and the pulse width is as low as 6 ms. When a fixed voltage is applied to the sensor, the output signal is a current pulse; when the current passing through the sensor is fixed, the output signal is a voltage pulse. When the light intensity increases, the pulse is in the positive direction; when the light intensity decreases, the pulse is in the negative direction. The peak intensity of the pulse is positively correlated with the amplitude of the light intensity change.

[0040] 3. The sensor of the present invention solves the disadvantages of the existing event sensor, such as complex circuit and large area of the sensing unit. It has the advantages of high integration density and low energy consumption. Moreover, the output signal has a change in the peak intensity of the pulse, which can reflect the amplitude of the light intensity change.

[0041] 4. The event sensor provided by the present invention detects the change of light intensity and generates voltage or current pulses. When the light intensity increases, the directions of the voltage and current are positive; when the light intensity decreases, they are negative. The peak values of the voltage and current are positively correlated with the amplitude of the light intensity change. The present invention uses a device with a single diode structure to achieve event-based photoelectric detection, which can be applied to new cameras and machine vision systems. Description of the Drawings

[0042] Figure 1 It is a schematic diagram of the structural connection of the event sensor of the present invention;

[0043] Figure 2 It is a transmission electron micrograph of the cross-section of the device structure in Embodiment 1 of the present invention;

[0044] Figure 3 It is a schematic diagram of the cross-electrode device array in Embodiment 1 of the present invention;

[0045] Figure 4 It is a light response curve graph when a fixed voltage is applied in Embodiment 1 of the present invention;

[0046] Figure 5 It is a light response curve graph when a fixed current is applied in Embodiment 1 of the present invention;

[0047] Figure 6 It is a light response pulse shape graph when a fixed current is applied in Embodiment 1 of the present invention;

[0048] Figure 7 It is a graph showing the relationship between the light response and the light intensity when a fixed current is applied in Embodiment 1 of the present invention;

[0049] Figure 8 It is a graph showing the relationship between the light detection quantum efficiency and the light wavelength in Embodiment 1 of the present invention;

[0050] Figure 9 It is an imaging graph of a waving gesture in Embodiment 1 of the present invention;

[0051] Figure 10Light response curve graph at a fixed current for Embodiment 2 of the present invention;

[0052] Figure 11 Light response curve graph at a fixed current for Embodiment 3 of the present invention;

[0053] Figure 12 Light response curve graph at a fixed current for Embodiment 4 of the present invention;

[0054] Figure 13 Light response curve graph at a fixed current for Embodiment 5 of the present invention;

[0055] Figure 14 Light response curve graph at a fixed current for Embodiment 6 of the present invention;

[0056] Figure 15 Light response curve graph at a fixed current for Embodiment 7 of the present invention. Detailed implementation manners

[0057] The present invention will be further described in detail below through specific embodiments. The following embodiments are only descriptive and not restrictive, and the protection scope of the present invention cannot be limited thereby.

[0058] The raw materials used in the present invention are all conventional commercially available products without special instructions. The methods used in the present invention are all conventional methods in the art without special instructions. The masses of various substances used in the present invention are all conventional usage masses. The structures, connection relationships, etc. not described in detail in the present invention can be understood as conventional technical means in the art.

[0059] A diode-type event sensor, as Figure 1 shown, the sensor includes a substrate 1, a bottom electrode 2, an electron transport layer 3, a receptor layer 4, a donor layer 5, an electrode modification layer 6, and a top electrode 7 which are sequentially connected from bottom to top.

[0060] Preferably, a substrate, a transparent bottom electrode formed on the substrate, an electron transport layer formed on the bottom electrode, an electron acceptor formed on the electron transport layer, an electron donor doped with a P-type dopant formed on the acceptor, an electrode modification layer formed on the donor, and a top electrode formed on the electrode modification layer.

[0061] Preferably, the substrate material is selected from a glass sheet, a PET plastic film, or a PI plastic film;

[0062] Alternatively, the transparent bottom electrode is selected from any one or a combination of indium tin oxide (ITO) glass, fluorine-doped tin dioxide (FTO) glass, and aluminum-doped zinc oxide (AZO) glass; the thickness of the bottom electrode is 80 - 150 nm;

[0063] Alternatively, the electron transport layer is selected from any one or a combination of zinc oxide, tin dioxide, PFN, PFN-Br, PEI, and PEIE; the material concentration is 80-120 mg / mL;

[0064] Alternatively, the acceptor material is selected from any one or a combination of N2200, Y6, ITIC, and PC60BM; the material concentration is 8-15 mg / mL;

[0065] The structural formula of the above-mentioned compound is as follows:

[0066]

[0067]

[0068] Furthermore, the donor material is selected from any one or a combination of PM6, D18, PBDB-T, J52, P3HT, and PTB7-Th, and any one or a combination of BCF, BF3, F4TCNQ, and iodine vapor is added as a dopant; the concentration of the donor layer material is 5-10 mg / mL, and the addition amount of the dopant is 5-20% of the mass of the donor layer;

[0069] The structural formula of the above-mentioned compound is as follows:

[0070]

[0071]

[0072] Preferably, the electrode modification layer is selected from any one or a combination of LiF, PFN, PFN-Br, BCP, PEI, and PEIE; the thickness of the electrode modification layer is 5-15 nm;

[0073] The structural formula of the above-mentioned compound is as follows:

[0074]

[0075]

[0076] Preferably, the electrode modification layer is selected from materials that can reduce the work function of the top electrode or reduce interface defects.

[0077] Alternatively, the top electrode material is selected from any one or a combination of calcium, magnesium, aluminum, and ytterbium;

[0078] Alternatively, the top electrode material is selected from a conductive material with a work function less than 4 eV or a conductive material with a work function less than 4 eV after combination with the electrode modification layer;

[0079] Alternatively, the thickness of the top electrode is 50-100 nm

[0080] Preferably, both the bottom electrode and the top electrode are strip-shaped and perpendicular to each other, forming a cross electrode array, and each intersection is a sensor pixel. The donor and the acceptor form a P-N junction, and a photo-generated voltage of 0V - 0.8V can be generated under illumination. The donor forms a Schottky contact with the top electrode, having an interfacial barrier greater than 0.5eV.

[0081] The preparation method of the diode-type event sensor as described above includes the following steps:

[0082] (1) Deposit a bottom electrode on a clean substrate material by magnetron sputtering or spin coating method;

[0083] (2) Spin coat or scrape coat an electron transport layer on the bottom electrode, and its solvent is any one or a combination of ethanol, methanol, water, and 2-methoxyethanol;

[0084] (3) Spin coat or scrape coat an acceptor layer on the electron transport layer, and its solvent is one or a combination of chloroform, toluene, and chlorobenzene;

[0085] (4) Spin coat or scrape coat a donor layer on the acceptor layer, and its solvent is one or a combination of chloroform, carbon disulfide, and tetrahydrofuran, and its solubility is orthogonal to the acceptor solvent and will not damage the acceptor layer;

[0086] (5) Spin coat or vacuum deposit an electrode modification layer on the donor layer, and the spin coating solvent is any one or a combination of ethanol, methanol, water, and 2-methoxyethanol;

[0087] (6) Vacuum deposit a top electrode on the electrode modification layer.

[0088] The application of the event sensor as described above in the Internet of Things and / or new cameras.

[0089] The application of the event sensor as described above in a machine vision system.

[0090] Specifically, the related preparation and detection are as follows:

[0091] Example 1

[0092] The preparation and performance test of a diode-type event sensor:

[0093] A number of glass substrates, with a specification of 15 mm × 15 mm square pieces. Magnetron sputtering is used to deposit ITO with a thickness of 120 nm, and the sheet resistance is about 20 Ω / sq. The ITO glass is ultrasonically cleaned in detergent, deionized water, acetone, and isopropyl alcohol for 30 minutes respectively. The ITO glass is dried under nitrogen conditions and cleaned by plasma with a power of 100 W for 1 minute. Zinc acetate dihydrate is dissolved in 2-methoxyethanol to form a solution of 100 mg / ml, 2% (by volume) of ethanolamine is added, and after stirring for 6 hours to dissolve, it is filtered using a 0.25 μm pore size PVDF filter head and spin-coated on the ITO glass at a speed of 3000 revolutions per minute. After annealing at 200 °C for 20 minutes, it is transferred to a nitrogen glove box for standby. N2200 is dissolved in chlorobenzene solution with a concentration of 10 mg / ml, and after complete dissolution, it is spin-coated at a speed of 2500 revolutions per minute and annealed at 100 °C for 15 minutes. PBDB-T is dissolved in tetrahydrofuran (THF) solution with a concentration of 8 mg / ml, 15% (by mass of the donor) of BCF dopant is added, and after complete dissolution, it is spin-coated at a speed of 2500 revolutions per minute. Finally, a 10 nm thick LiF and an 80 nm thick Mg are deposited as the top electrode by vacuum evaporation.

[0094] Performance test of the diode-type event sensor as described above:

[0095] As Figure 2 shown is the cross-sectional transmission electron micrograph of the device structure. As Figure 3 shown is the schematic diagram of the cross-electrode device array. When the voltage at both ends is fixed at 0.01 V, the response of the sensor to a 1 s light signal is as Figure 4 shown. Positive and negative current pulses are generated respectively when the light intensity increases and decreases. The energy consumption per single pulse is as low as 30 fJ. When the passing current is fixed at 0 A, the response of the sensor to a 1 s light signal is as Figure 5 shown. Positive and negative voltage pulses are generated respectively when the light intensity increases and decreases. The nature of the pulse signal is as Figure 6 shown. The response speed can reach 0.2 ms, and the pulse width is only 6 ms. When the light intensity is changed, the response signal of the sensor is as Figure 7 shown. The positive and negative pulse peaks are respectively between 0 V and 0.8 V and between 0 V and -0.7 V, and the amplitude increases with the increase of the light intensity. The relationship between the response intensity of the device and the light wavelength is as Figure 8 shown. It has a response in the visible light range. The imaging of the sensor is as Figure 9 shown, and it can detect and image motion information.

[0096] Example 2

[0097] Preparation and performance test of a diode-type event sensor:

[0098] A number of PET plastic substrates, in the form of 15 mm × 15 mm square pieces. Magnetron sputtering deposition of 120 nm thick FTO, with a sheet resistance of approximately 43 Ω / sq. Ultrasonically clean the FTO glass in detergent, deionized water, acetone, and isopropyl alcohol for 30 minutes respectively. Dry the FTO glass under nitrogen conditions and use plasma cleaning at 100 W power for 1 minute. Dissolve zinc acetate dihydrate in 2-methoxyethanol to form a solution of 100 mg / ml, add 2% by volume of ethanolamine, stir for 6 hours to dissolve, then filter using a 0.25 μm pore size PVDF filter head, and spin-coat on the FTO glass at a speed of 3000 revolutions per minute. After annealing at 200 °C for 20 minutes, transfer it to a nitrogen glove box for standby. Dissolve N2200 in chlorobenzene solution at a concentration of 10 mg / ml, spin-coat at a speed of 2500 revolutions per minute after complete dissolution, and anneal at 100 °C for 15 minutes. Dissolve PBDB-T in tetrahydrofuran (THF) solution at a concentration of 8 mg / ml, add 15% of the donor mass of BCF dopant, spin-coat at a speed of 2500 revolutions per minute after complete dissolution. Finally, use vacuum evaporation to deposit a 10 nm thick LiF and an 80 nm thick Mg as the top electrode. The response of the sensor to a 1 s light signal when the fixed passing current is 0 A is as Figure 10 shown, generating positive and negative voltage pulses respectively when the light intensity increases and decreases.

[0099] Example 3

[0100] Preparation and performance testing of a diode-type event sensor:

[0101] A number of PI plastic substrates, in the form of 15 mm × 15 mm square pieces. Magnetron sputtering deposition of 120 nm thick AZO, with a sheet resistance of approximately 105 Ω / sq. Ultrasonically clean the AZO glass in detergent, deionized water, acetone, and isopropyl alcohol for 30 minutes respectively. Dry the AZO glass under nitrogen conditions and use plasma cleaning at 100 W power for 1 minute. Dissolve zinc acetate dihydrate in 2-methoxyethanol to form a solution of 100 mg / ml, add 2% by volume of ethanolamine, stir for 6 hours to dissolve, then filter using a 0.25 μm pore size PVDF filter head, and spin-coat on the AZO glass at a speed of 3000 revolutions per minute. After annealing at 200 °C for 20 minutes, transfer it to a nitrogen glove box for standby. Dissolve N2200 in chlorobenzene solution at a concentration of 10 mg / ml, spin-coat at a speed of 2500 revolutions per minute after complete dissolution, and anneal at 100 °C for 15 minutes. Dissolve PBDB-T in tetrahydrofuran (THF) solution at a concentration of 8 mg / ml, add 15% of the donor mass of BCF dopant, spin-coat at a speed of 2500 revolutions per minute after complete dissolution. Finally, use vacuum evaporation to deposit a 10 nm thick LiF and an 80 nm thick Mg as the top electrode. The response of the sensor to a 1 s light signal when the fixed passing current is 0 A is asFigure 11 As shown, positive and negative voltage pulses are generated respectively when the light intensity increases and decreases.

[0102] Example 4

[0103] Preparation and performance test of a diode-type event sensor:

[0104] Several glass substrates with a specification of 15 mm × 15 mm square pieces. ITO with a thickness of 120 nm is deposited by magnetron sputtering, and the sheet resistance is about 20 Ω / sq. The ITO glass is ultrasonically cleaned in detergent, deionized water, acetone, and isopropyl alcohol for 30 minutes respectively. The ITO glass is dried under nitrogen conditions and cleaned by plasma with a power of 100 W for 1 minute. Zinc acetate dihydrate is dissolved in 2-methoxyethanol to form a solution of 100 mg / ml, 2% by volume of ethanolamine and 25% by mass of PEI are added, stirred for 6 hours to dissolve, filtered using a 0.25 μm pore size PVDF filter head, and spin-coated on the ITO glass at a speed of 3000 rpm. After annealing at 200 °C for 20 minutes, it is transferred to a nitrogen glove box for standby. N2200 and Y6 are dissolved in a chlorobenzene solution in a mass ratio of 2:1, with a total concentration of 10 mg / ml. After complete dissolution, it is spin-coated at a speed of 2500 rpm and annealed at 100 °C for 15 minutes. D18 is dissolved in a chloroform (CF) solution with a concentration of 8 mg / ml, 15% of the donor mass of BF3 dopant is added, and after complete dissolution, it is spin-coated at a speed of 2500 rpm. PFN is dissolved in a methanol solution with a concentration of 1 mg / ml, and after complete dissolution, it is spin-coated at a speed of 3500 rpm as the electrode modification layer. Finally, magnesium with a thickness of 20 nm and aluminum with a thickness of 60 nm are sequentially evaporated by vacuum evaporation as the top electrode. The response of the sensor to a light signal lasting for 1 s when the fixed passing current is 0 A is as Figure 12 As shown, positive and negative voltage pulses are generated respectively when the light intensity increases and decreases.

[0105] Example 5

[0106] Preparation and performance test of a diode-type event sensor:

[0107] Several glass substrates, in the form of 15 mm × 15 mm square pieces. Magnetron sputtering deposition of ITO with a thickness of 120 nm, and the sheet resistance is about 20 Ω / sq. Ultrasonically clean the ITO glass in detergent, deionized water, acetone, and isopropanol for 30 minutes respectively. Dry the ITO glass under nitrogen conditions and clean it with a plasma at a power of 100 W for 1 minute. Add PEIE with a mass ratio of 5% of the mass of tin dioxide to the ethanol dispersion of tin dioxide nanoparticles with a mass ratio of 10%, and spin-coat it on the ITO glass at a speed of 3000 revolutions per minute. After annealing at 200 °C for 20 minutes, transfer it to a nitrogen glove box. Dissolve N2200 and ITIC in a chlorobenzene solution at a mass ratio of 2:1, with a total concentration of 10 mg / ml. After complete dissolution, spin-coat it at a speed of 2500 revolutions per minute and anneal at 100 °C for 15 minutes. Dissolve PM6 in a tetrahydrofuran (THF) solution with a concentration of 8 mg / ml, add a dopant of F4TCNQ with a mass ratio of 15% of the donor, and spin-coat it at a speed of 2500 revolutions per minute after complete dissolution. Finally, use vacuum evaporation to sequentially deposit a 10-nm-thick BCP, a 20-nm-thick calcium, and a 60-nm-thick aluminum as the top electrode. When the fixed passing current is 0 A, the response of the sensor to a light signal lasting for 1 s is as Figure 13 shown, generating positive and negative voltage pulses respectively when the light intensity increases and decreases.

[0108] Example 6

[0109] Preparation and performance testing of a diode-type event sensor:

[0110] Several glass substrates, in the form of 15 mm × 15 mm square pieces. Magnetron sputtering deposition of ITO with a thickness of 120 nm, and the sheet resistance is about 20 Ω / sq. Ultrasonically clean the ITO glass in detergent, deionized water, acetone, and isopropanol for 30 minutes respectively. Dry the ITO glass under nitrogen conditions and clean it with a plasma at a power of 100 W for 1 minute. Take an ethanol dispersion of tin dioxide nanoparticles with a mass ratio of 10%, and spin-coat it on the ITO glass at a speed of 3000 revolutions per minute. Anneal at 200 °C for 20 minutes. Dissolve PFN-Br in a methanol solution with a concentration of 1 mg / ml, and spin-coat it at a speed of 3500 revolutions per minute after complete dissolution to form an electron transport layer together with tin dioxide. Then transfer it to a nitrogen glove box. Dissolve PC60BM in a chlorobenzene solution with a total concentration of 20 mg / ml, and spin-coat it at a speed of 2000 revolutions per minute after complete dissolution. Anneal at 100 °C for 15 minutes. Dissolve the P3HT donor in a tetrahydrofuran (THF) solution with a concentration of 8 mg / ml, add a dopant of F4TCNQ with a mass ratio of 5% of the donor, and spin-coat it at a speed of 2500 revolutions per minute after complete dissolution. Finally, use vacuum evaporation to sequentially deposit a 20-nm-thick ytterbium and a 60-nm-thick aluminum as the top electrode. When the fixed passing current is 0 A, the response of the sensor to a light signal lasting for 1 s is asFigure 14 As shown, positive and negative voltage pulses are generated respectively when the light intensity increases and decreases.

[0111] Example 7

[0112] Preparation and performance testing of a diode-type event sensor:

[0113] Several glass substrates with a specification of 15 mm × 15 mm square pieces. Magnetron sputtering is used to deposit ITO with a thickness of 120 nm, and the sheet resistance is about 20 Ω / sq. The ITO glass is ultrasonically cleaned in detergent, deionized water, acetone, and isopropanol for 30 minutes respectively. The ITO glass is dried under nitrogen conditions and cleaned with a plasma at a power of 100 W for 1 minute. PEI is dissolved in a methanol solution with a concentration of 4 mg / ml, and after complete dissolution, it is spin-coated at a speed of 3500 rpm as the electron transport layer. Then it is transferred to a nitrogen glove box for standby. The ITIC acceptor material is dissolved in a chlorobenzene solution with a concentration of 10 mg / ml, and after complete dissolution, it is spin-coated at a speed of 2500 rpm and annealed at 100 °C for 15 minutes. The PTB7-Th donor material is dissolved in a tetrahydrofuran (THF) solution with a concentration of 8 mg / ml, and after complete dissolution, it is spin-coated at a speed of 2500 rpm. Iodine solid is placed in a glass bottle on a 100 °C heating table, and the device is placed at the bottle mouth to be smoked with iodine vapor for 1 minute. Finally, a 10-nm-thick LiF and an 80-nm-thick aluminum are deposited by vacuum evaporation as the top electrode. The response of the sensor to a 1-s light signal when the fixed passing current is 0 A is as Figure 15 As shown, positive and negative voltage pulses are generated respectively when the light intensity increases and decreases.

[0114] Although embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art can understand that: without departing from the spirit and scope of the present invention and the appended claims, various substitutions, changes, and modifications are possible. Therefore, the scope of the present invention is not limited to the content disclosed in the embodiments.

Claims

1. A diode-type event sensor, characterized in that: The sensor includes a substrate, a bottom electrode, an electron transport layer, a receptor layer, a donor layer, an electrode modification layer, and a top electrode, which are sequentially connected from bottom to top.

2. The diode-type event sensor according to claim 1, wherein: A substrate, a transparent bottom electrode formed on the substrate, an electron transport layer formed on the bottom electrode, an electron acceptor formed on the electron transport layer, an electron donor doped with a P-type dopant formed on the acceptor, an electrode modification layer formed on the donor, and a top electrode formed on the electrode modification layer.

3. The diode-type event sensor according to claim 1, characterized in that: The substrate material is selected from a glass sheet, a PET plastic film, or a PI plastic film; Alternatively, the transparent bottom electrode is selected from any one or a combination of indium tin oxide (ITO) glass, fluorine-doped tin dioxide (FTO) glass, and aluminum-doped zinc oxide (AZO) glass; the thickness of the bottom electrode is 80 - 150 nm; Alternatively, the electron transport layer is selected from any one or a combination of zinc oxide, tin dioxide, PFN, PFN-Br, PEI, and PEIE; the material concentration is 80 - 120 mg / mL; Alternatively, the material of the receptor layer is selected from any one or a combination of N2200, Y6, ITIC, and PC60BM; the material concentration is 8 - 15 mg / mL.

4. The diode-type event sensor according to claim 1, wherein: The material of the donor layer is selected from any one or a combination of PM6, D18, PBDB-T, J52, P3HT, and PTB7-Th, and any one or a combination of BCF, BF3, F4TCNQ, and iodine vapor is added as a dopant; the concentration of the donor layer material is 5 - 10 mg / mL, and the addition amount of the dopant is 5 - 20% of the mass of the donor layer.

5. The diode-type event sensor according to claim 1, wherein: The electrode modification layer is selected from any one or a combination of LiF, PFN, PFN-Br, BCP, PEI, and PEIE; the thickness of the electrode modification layer is 5 - 15 nm.

6. The diode type event sensor according to claim 1, wherein: The electrode modification layer is selected from materials that can reduce the work function of the top electrode or reduce interface defects; Alternatively, the top electrode material is selected from any one or a combination of calcium, magnesium, aluminum, and ytterbium; Alternatively, the top electrode material is selected from a conductive material with a work function less than 4 eV or a conductive material with a work function less than 4 eV after combination with the electrode modification layer; Alternatively, the thickness of the top electrode is 50 - 100 nm.

7. The diode type event sensor according to any one of claims 1 to 6, characterized in that: Both the bottom electrode and the top electrode are strip-shaped and perpendicular to each other, forming a cross electrode array, and each intersection point is a sensor pixel. The donor and the receptor form a P-N junction, and a photocurrent voltage of 0 V - 0.8 V can be generated under light. The donor and the top electrode form a Schottky contact, with an interface barrier greater than 0.5 eV.

8. The manufacturing method of the diode type event sensor according to any one of claims 1 to 7, characterized in that: It includes the following steps: (1) Deposit a bottom electrode on a clean substrate using magnetron sputtering or spin coating; (2) Spin coat or scrape coat an electron transport layer on the bottom electrode, and the solvent is any one or a combination of ethanol, methanol, water, and 2-methoxyethanol; (3) Spin coat or scrape coat a receptor layer on the electron transport layer, and the solvent is one of chloroform, toluene, and chlorobenzene; (4) Spin-coat or blade-coat a donor layer on the receptor layer, with a solvent being one or a combination of chloroform, carbon disulfide, and tetrahydrofuran. Its solubility is orthogonal to the receptor solvent and will not damage the receptor layer; (5) Spin-coat or vacuum-deposit an electrode modification layer on the donor layer, with the spin-coating solvent being any one or a combination of ethanol, methanol, water, and 2-methoxyethanol; (6) Vacuum-deposit a top electrode on the electrode modification layer.

9. The application of the event sensor according to any one of claims 1 to 7 in the Internet of Things and / or new cameras.

10. The application of the event sensor according to any one of claims 1 to 7 in a machine vision system.

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