Method for regulating and controlling photoelectric response rate of photoelectric memristor and obtained photoelectric memristor

Abstract

The invention discloses a method for regulating and controlling the photoelectric response rate of a photoelectric memristor and the obtained photoelectric memristor, the photoelectric response rate of the photoelectric memristor is regulated and controlled by regulating and controlling the structure and oxygen vacancy content of a memristor functional layer, and the memristor functional layer is of a double-layer structure. The memristive function layer 1 close to the bottom electrode is a metal oxide layer containing oxygen vacancies, and the memristive function layer 2 close to the top electrode is a metal oxide layer. The photoresponse speed of the photoelectric memristor is regulated and controlled by regulating and controlling the memristor function layer of the photoelectric memristor, and a thought is provided for solving the problem of slow response of the photoelectric memristor.

Description

Technical Field

[0001] The present invention relates to a method for regulating the optoelectronic response rate of an optoelectronic memristor, specifically to a method for regulating the optoelectronic response rate of an optoelectronic memristor based on the oxygen source content, and also relates to an optoelectronic memristor and a preparation method thereof, which are applicable to large-scale sense-storage-computation networks based on optoelectronic memristors, belonging to the field of semiconductor technology processes. Background Art

[0002] In the traditional von Neumann architecture, the computing and storage of a computer are separated, and data is exchanged between the central processing unit (CPU) and memory through a bus. This architecture faces the "von Neumann bottleneck", that is, the data transmission speed is much lower than the processing speed, resulting in low computing efficiency. Especially when dealing with a large amount of data, data transmission becomes the bottleneck of system performance. The inherent limitations of the von Neumann architecture have promoted the exploration of new computing architectures, including brain-inspired computing, parallel computing, and storage-computation integration based on new materials (such as memristors, optoelectronic memristors), etc. In this context, memristors, as a new type of device, have attracted extensive attention. Memristors are elements that can remember the history of charge flow and have the characteristics of non-volatility and adjustable resistance. They can maintain information without power supply, thus breaking through the storage-computation separation problem in the von Neumann architecture to a certain extent. However, memristors mainly regulate the conductance state through current, which can provide efficient storage and processing, but they still have limitations in response speed and flexibility. The introduction of optoelectronic memristors provides new advantages in many aspects, especially when dealing with the bottleneck of the von Neumann architecture, showing great potential.

[0003] Optoelectronic memristors can regulate their conductance state through external optical signals (such as light intensity, wavelength, duration, etc.), which makes optoelectronic memristors superior to traditional memristors in performance. And optoelectronic memristors can process optical signals and electrical signals simultaneously. This characteristic enables it to achieve more efficient parallel computing in the information processing process. At the same time, compared with electrical regulation, optical regulation naturally has lower energy consumption and higher parallel computing ability. Optoelectronic memristors overcome the storage-computation separation problem in the von Neumann architecture by introducing optical signals to regulate the conductance state of the device, and can efficiently process parallel computing tasks. Compared with traditional memristors, optoelectronic memristors have significant advantages in response speed, energy efficiency, and processing ability, showing great potential in the fields of optoelectronic integration, intelligent computing, etc.

[0004] However, currently, optoelectronic memristors generally have the problem of slow optical response rate. This problem leads to increased energy consumption, weakened parallel ability, and increased time delay when optoelectronic memristors participate in constructing a storage-computation network, and then results in a decrease in the computing speed of the entire network, greatly affecting the application of optoelectronic memristors in the storage-computation network. Summary of the Invention

[0005] In view of the deficiencies of optoelectronic memristors, the present invention provides a method for regulating the optoelectronic response rate of an optoelectronic memristor. By selecting the composition and structure of the memristive functional layer of the optoelectronic memristor and controlling the oxygen source content, the optoelectronic response rate of the optoelectronic memristor is regulated.

[0006] The specific technical solution of the present invention is as follows:

[0007] A method for regulating the optoelectronic response rate of an optoelectronic memristor, the optoelectronic memristor includes a bottom electrode, a memristive functional layer and a top electrode. The optoelectronic response rate of the optoelectronic memristor is regulated by controlling the memristive functional layer. The memristive functional layer is a bilayer structure. The memristive functional layer 1 close to the bottom electrode is a metal oxide layer with adjustable oxygen vacancies, and the memristive functional layer 2 close to the top electrode is a metal oxide layer. By designing the memristive functional layer, such as composition, structure, oxygen vacancy content, the optoelectronic response rate of the optoelectronic memristor is regulated.

[0008] Further, the memristive functional layer 1 is a HfO x layer or a TiO x layer, where x ≤ 2.

[0009] Further, the memristive functional layer 2 is a TiO2 layer or a SnO2 layer.

[0010] Further, the memristive functional layer 1 is preferably a HfO x layer, and the memristive functional layer 2 is preferably a TiO2 layer. The combination of these two shows better optoelectronic properties and a greater increase in the photocurrent speed.

[0011] Further, the thickness of the memristive functional layer 1 is 5 - 10 nm, and the thickness of the memristive functional layer 2 is 3 - 5 nm.

[0012] Further, the memristive functional layer 1 and the memristive functional layer 2 are formed by atomic layer deposition (ALD) technology, using H2O as the oxygen precursor source. By controlling the ratio of the oxygen precursor source and the metal precursor source, metal oxide layers with different oxygen vacancy contents are formed. Reducing the amount of water source introduced can increase the oxygen vacancy content. The oxygen vacancy content inside and at the interface of the memristive functional layer 1 enables photo-generated electrons to form a conductive channel in the memristive functional layer 1 faster, accelerating the light response speed of the device. The more the oxygen vacancy content, the faster the light response speed.

[0013] Further, the HfO x layer uses H2O source and hafnium tetrakis(dimethylamino) as the precursor source, and is formed by multiple atomic layer deposition cycles at a temperature of 200 - 250 °C to form the required thickness of HfO xLayer. In each deposition cycle, the pulse duration of the H2O source is 5 - 20 ms, such as 5 ms, 10 ms, 15 ms, 20 ms, and the pulse duration of hafnium tetrakis(dimethylamino) is 25 - 35 ms, such as 25 ms, 30 ms, 35 ms. When the feeding rates of the water source and hafnium tetrakis(dimethylamino) source are the same, different oxygen vacancy contents can be achieved by regulating the feeding time of these two in each deposition cycle.

[0014] Further, the TiO x layer uses the H2O source and titanium tetrakis(dimethylamino) source as precursor sources, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form the TiO x layer with the required thickness. In each deposition cycle, the pulse duration of the H2O source is 5 - 20 ms, such as 5 ms, 10 ms, 15 ms, 20 ms, and the pulse duration of the titanium tetrakis(dimethylamino) source is 25 - 35 ms, such as 25 ms, 30 ms, 35 ms. Similarly, when the feeding rates of the water source and titanium tetrakis(dimethylamino) source are the same, different oxygen vacancy contents can be achieved by regulating the feeding time of these two in each deposition cycle.

[0015] Further, the TiO2 layer uses the H2O source and titanium tetrakis(dimethylamino) source as precursor sources, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form the TiO2 layer with the required thickness. In each deposition cycle, the pulse duration of the H2O source is 25 - 35 ms, such as 25 ms, 30 ms, 35 ms, and the pulse duration of the titanium tetrakis(dimethylamino) source is 25 - 35 ms, such as 25 ms, 30 ms, 35 ms. In each deposition cycle, the molar ratio of O to Ti is 2:1.

[0016] Further, the SnO2 layer uses the H2O source and tin tetrakis(dimethylamino) source as precursor sources, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form the SnO2 layer with the required thickness. In each deposition cycle, the pulse duration of the H2O source is 25 - 35 ms, such as 25 ms, 30 ms, 35 ms, and the pulse duration of the tin tetrakis(dimethylamino) source is 25 - 35 ms, such as 25 ms, 30 ms, 35 ms. In each deposition cycle, the molar ratio of O to Sn is 2:1.

[0017] The present invention provides a photoelectric memristor, which includes a bottom electrode, a memristive functional layer, and a top electrode from bottom to top. The memristive functional layer is a bilayer structure, including a memristive functional layer 1 and a memristive functional layer 2. The memristive functional layer 1 close to the bottom electrode is a metal oxide layer with adjustable oxygen vacancies, and the memristive functional layer 2 close to the top electrode is a metal oxide layer.

[0018] Further, the memristive functional layer 1 is an HfO layer or a TiO layer with adjustable oxygen vacancies, where x ≤ 2, preferably an HfO layer. x layer or TiO x layer, x ≤ 2, preferably an HfO x layer.

[0019] Further, the memristive functional layer 2 is a TiO2 layer or an SnO2 layer, preferably a TiO2 layer.

[0020] Further, the thickness of the memristive functional layer 1 is 5 - 10 nm, such as 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm. The thickness of the memristive functional layer 2 is 3 - 5 nm, such as 3 nm, 4 nm, 5 nm.

[0021] Further, the memristive functional layer is prepared by atomic layer deposition. When the memristive functional layer 1 is an HfO layer or a TiO layer, an H2O source, hafnium tetrakis(dimethylamino) or titanium tetrakis(dimethylamino) source is used as the precursor source, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form an HfO layer or a TiO layer. At the same gas inlet rate, the pulse duration of the H2O source for each deposition cycle is 5 - 20 ms, and the pulse duration of hafnium tetrakis(dimethylamino) or titanium tetrakis(dimethylamino) source is 25 - 35 ms. x layer or TiO x layer, an H2O source, hafnium tetrakis(dimethylamino) or titanium tetrakis(dimethylamino) source is used as the precursor source, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form an HfO layer or a TiO layer. x layer or TiO x layer. At the same gas inlet rate, the pulse duration of the H2O source for each deposition cycle is 5 - 20 ms, and the pulse duration of hafnium tetrakis(dimethylamino) or titanium tetrakis(dimethylamino) source is 25 - 35 ms.

[0022] When the memristive functional layer 2 is a TiO2 layer or an SnO2 layer, an H2O source, titanium tetrakis(dimethylamino) or tin tetrakis(dimethylamino) source is used as the precursor source, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form a TiO2 layer or an SnO2 layer. At the same gas inlet rate, the pulse duration of the H2O source for each deposition cycle is 25 - 35 ms, and the pulse duration of titanium tetrakis(dimethylamino) or tin tetrakis(dimethylamino) source is 25 - 35 ms.

[0023] Further, the material of the bottom electrode is a light-transmitting material such as ITO or TiN, a conductive oxygen-absorbing material. The material of the top electrode is a light-transmitting material ITO.

[0024] Further, the thickness of the bottom electrode is 70 - 100 nm, and the thickness of the top electrode is 50 - 70 nm.

[0025] Further, the bottom electrode is integral, and the memristive functional layer shares the bottom electrode. The top electrode is discontinuous and separated.

[0026] Further, the optoelectronic memristor further includes a substrate. The material of the substrate is preferably a P-type Si substrate. The resistivity range of the substrate is 0.002 - 0.004 Ω·cm, and the thickness of the substrate is preferably 400 - 600 nm.

[0027] Furthermore, the optoelectronic memristor is an analog memristor with a gradually varying resistance state with voltage, having an operating voltage range between -4V and 3V, a switching ratio of 3.8 - 5.2, and the optoelectronic memristor is a non-volatile bipolar device.

[0028] The present invention also provides a method for preparing an optoelectronic memristor, which comprises the following steps:

[0029] (1) Place the cleaned substrate into the reaction chamber of a magnetron sputtering device, and obtain a bottom electrode through magnetron sputtering;

[0030] (2) Place the substrate with the bottom electrode into the reaction chamber of an atomic layer deposition device. Using H2O source, hafnium tetrakis(dimethylamido) source or titanium tetrakis(dimethylamido) source as the precursor source, deposit multiple cycles at a temperature of 200 - 250 °C to obtain the memristive functional layer 1. The pulse duration of the H2O source for each cycle is 5 - 20 ms, and the pulse duration of the hafnium tetrakis(dimethylamido) source or titanium tetrakis(dimethylamido) source is 25 - 35 ms; Using H2O source, titanium tetrakis(dimethylamido) source or tin tetrakis(dimethylamido) source as the precursor source, deposit multiple cycles at a temperature of 200 - 250 °C to obtain the memristive functional layer 2. The pulse duration of the H2O source for each cycle is 25 - 35 ms, and the pulse duration of the titanium tetrakis(dimethylamido) source or tin tetrakis(dimethylamido) source is 25 - 35 ms;

[0031] (3) Cover the memristive functional layer with a patterned mask template, and then place it into the reaction chamber of a magnetron sputtering device to obtain a top electrode through magnetron sputtering.

[0032] The optoelectronic memristor of the present invention includes three parts from bottom to top, namely a shared bottom electrode, a double-layer memristive functional layer, and a separated top electrode. By regulating the memristive functional layer of the optoelectronic memristor, the light response speed of the optoelectronic memristor is regulated, providing an idea for solving the problem of slow response of the optoelectronic memristor. The present invention has the following beneficial effects:

[0033] 1. The memristive functional layer of the present invention has a double-layer structure, one of which is a metal oxide layer with adjustable oxygen vacancies. The memristive functional layer is prepared by atomic layer deposition technology. During the preparation process, the content of oxygen vacancies is controlled by adjusting the input amount of the water source. The increase in the content of oxygen vacancies changes the photogenerated electron mobility, thereby changing the light response speed of the optoelectronic memristor and changing the conductance change amount of the optoelectronic memristor under the same illumination time.

[0034] 2. The present invention has screened the composition of the memristive functional layer, and the preferred structure is ITO / HfO x / TiO2 / ITO(TE), the optoelectronic memristor with this structure exhibits better optoelectronic properties and a greater improvement in photoconduction speed. The optoelectronic memristor with this structure shows a gradually increasing conductance under light illumination, presenting an enhanced photoconduction effect. Description of the Drawings

[0035] Figure 1 is a schematic diagram of the structure and preparation process of the optoelectronic memristor of Example 1;

[0036] Figure 2 is the result diagram of the elemental content analysis of two HfO x layers with different oxygen contents in Example 1 by EDS;

[0037] Figure 3 are the current-voltage curves of the optoelectronic memristors with two different oxygen contents in Example 1 under light and no-light illumination, (a) O-Low, (b) O-High;

[0038] Figure 4 is the light response of the optoelectronic memristors with two different oxygen contents in Example 1 under different light illumination conditions;

[0039] Figure 5 is the light response of the optoelectronic memristors with two different oxygen contents in Example 2 under different light illumination conditions. Detailed Description of the Invention

[0040] The following describes exemplary embodiments of the present invention, including various details of the embodiments of the present invention to facilitate understanding. It should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and conciseness, the description of well-known functions, operations, and structures is omitted below.

[0041] Unless otherwise defined, the technical and scientific terms in this specification have the same meaning as commonly understood by those skilled in the art. Although methods and materials similar or equivalent to those described herein can be used in experiments or practical applications, the materials and methods are described herein. In case of conflict, the present specification, including the definitions therein, shall prevail.

[0042] Example 1

[0043] An optoelectronic memristor based on the ITO / HfO x / TiO2 / ITO(TE) structure. As Figure 1 shown, from bottom to top, it includes the following parts: P-type - Si substrate, ITO bottom electrode, HfO x / TiO2 double-layer memristive functional layer and ITO top electrode. The thickness of the P-type -Si substrate is 500 nm, the thickness of the ITO bottom electrode is 80 nm, and the thickness of the HfO x The thickness of the memristive functional layer is 10 nm, the thickness of the TiO2 memristive functional layer is 3 nm, and the thickness of the ITO top electrode is 60 nm.

[0044] The following method is used to prepare two kinds of optoelectronic memristors with different oxygen contents in the HfO x layer, and the steps are as follows:

[0045] (1) Substrate preparation

[0046] The P-type -Si is cleaned with absolute ethanol and deionized water respectively, and then dried with high-purity nitrogen.

[0047] (2) Preparation of ITO bottom electrode

[0048] The cleaned P-type -Si is used as the substrate and placed in the reaction chamber of the magnetron sputtering equipment. Ar2 is ionized with 50 W AC power to generate glow discharge and bombard the ITO target to produce sputtering. The gas flow rate during the preparation process is 5 sccm, and an ITO layer with a thickness of 80 nm is prepared for 1200 s.

[0049] (3) Preparation of memristive functional layer

[0050] The substrate with the ITO bottom electrode is placed in the reaction chamber of the atomic layer deposition equipment. Using H2O source and hafnium tetrakis(dimethylamino) as the precursor sources, a HfO layer with a thickness of 10 nm is deposited at a temperature of 200 °C for 80 cycles; among them, when preparing the HfO layer of the O-High optoelectronic memristor, 25 ms of hafnium tetrakis(dimethylamino) source and 20 ms of H2O source are introduced in each cycle. When preparing the HfO layer of the O-Low optoelectronic memristor, 25 ms of hafnium tetrakis(dimethylamino) source and 5 ms of H2O source are introduced in each cycle; the introduction speeds of the H2O source and the hafnium tetrakis(dimethylamino) source are the same; x layer; among them, when preparing the HfO x layer, 25 ms of hafnium tetrakis(dimethylamino) source and 20 ms of H2O source are introduced in each cycle. When preparing the HfO x layer, 25 ms of hafnium tetrakis(dimethylamino) source and 5 ms of H2O source are introduced in each cycle; the introduction speeds of the H2O source and the hafnium tetrakis(dimethylamino) source are the same;

[0051] Using H2O source and titanium tetrakis(dimethylamino) as the precursor sources, a TiO2 layer is deposited at a temperature of 200 °C for 60 cycles. 25 ms of titanium tetrakis(dimethylamino) source and 20 ms of H2O source are introduced in each cycle; the introduction speeds of the H2O source and the titanium tetrakis(dimethylamino) source are the same.

[0052] (4) Preparation of ITO top electrode

[0053] On the HfO xPlace a mask with the top electrode pattern on the / TiO2 memristive functional layer. Put the substrate with the mask into the reaction chamber of a magnetron sputtering device. Ionize Ar2 with 50 W of AC power to make it glow and bombard the ITO target to generate sputtering. The gas flow rate during the preparation process is 5 sccm. Perform the preparation for 900 s to obtain an ITO layer with a thickness of 60 nm, and separate top electrodes are obtained. Finally, two optoelectronic memristive devices, O-High and O-Low, are obtained. These two devices are the same in other aspects, except that the oxygen content in the HfO x layer is different.

[0054] During the preparation of HfO x , put the HfO x with different oxygen contents obtained into an EDS analyzer for elemental content analysis. The results are as Figure 2 shown. It can be seen from the figure that the oxygen element content in the HfO x layer of the O-High device is higher than that of the O-Low device, while the content of hafnium element is almost indistinguishable. This shows that by reducing the inflow of the H2O source during the ALD preparation process, the O:Hf ratio in the HfO x layer can be reduced and the oxygen content can be decreased.

[0055] Perform current-voltage tests on the O-Low device and O-High under 14 mW, 360 nm ultraviolet light irradiation and in the dark condition. The results are as Figure 3 shown. It can be seen from the figure that (a) is the current-voltage curve of the O-Low device under light and dark conditions, and (b) is the current-voltage curve of the O-High device under light and dark conditions. It can be seen that in (a), light makes the conductance value reached by the device after Set higher and has non-volatility. At a read voltage of -1 V, the switching ratio is 5.2 in the dark condition and 6.8 in the light condition, showing an obvious difference; in (b), light enables the device to reach a higher resistance state during the Set process, but then decays and has volatility. At a read voltage of -1 V, the switching ratio is 3.82 in the dark condition and 3.91 in the light condition, with a very small difference. This shows that the O-Low device has a faster light response speed and higher intensity.

[0056] Use a B1500A semiconductor device analyzer and a probe station to test the light response characteristics of the O-Low device and the O-High device. The results are as Figure 4As shown, (a) shows the change values of the read current of the O-High device and the O-Low device under laser irradiation at 2 s, 10 mW, and different wavelengths (360 nm, 520 nm, 638 nm); (b) shows the change values of the read current of the O-High device and the O-Low device under laser irradiation at 200 ms, 360 nm wavelength, and different optical powers (0 - 25 mW); (c) shows the change values of the read current of the O-High device and the O-Low device under laser irradiation at 14 mW, 360 nm wavelength, and different illumination durations (20 ms - 1000 ms); the above read voltages are all set to -0.3 V. From Figure 4 As can be seen from (a), both the O-High device and the O-Low device are most sensitive to 360 nm ultraviolet light, with the strongest light response, followed by 520 nm green light, and the weakest is 638 nm red light. Moreover, the light response of the O-Low device is stronger than that of the O-High device; from Figure 4 As can be seen from (b), the light response amplitudes of both the O-High device and the O-Low device increase with the increase of optical power, and the light response of the O-Low device is stronger than that of the O-High device; from Figure 4 As can be seen from (c), the light response amplitudes of both the O-High device and the O-Low device increase with the increase of illumination time, and the light response of the O-Low device is stronger than that of the O-High device; the above shows that under the same illumination conditions, the light response speed of the O-Low device is faster than that of the O-High device.

[0057] Example 2

[0058] An optoelectronic memristor based on the ITO / TiO x / SnO2 / ITO(TE) structure, from bottom to top, includes the following parts: P-type - Si substrate, ITO bottom electrode, TiO x / SnO2 double-layer memristive functional layer, and ITO top electrode. The thickness of the P-type - Si substrate is 500 nm, the thickness of the ITO bottom electrode is 80 nm, the thickness of the TiO x memristive functional layer is 10 nm, the thickness of the SnO2 memristive functional layer is 3 nm, and the thickness of the ITO top electrode is 60 nm.

[0059] The following method is used to prepare optoelectronic memristors with HfO x layers with different oxygen contents, and the steps are as follows:

[0060] (1) Substrate preparation

[0061] The P-type - Si substrate is cleaned with anhydrous ethanol and deionized water respectively, and then dried with high-purity nitrogen.

[0062] (2) Preparation of ITO bottom electrode

[0063] Put the washed P-type - Si as the substrate into the reaction chamber of the magnetron sputtering equipment. Use 50W AC power to ionize Ar₂ to make it glow and bombard the ITO target to generate sputtering. The gas flow rate during the preparation process is 5 sccm, and carry out the preparation for 1200 s to prepare an ITO layer with a thickness of 80 nm.

[0064] (3) Prepare the memristive functional layer

[0065] Put the substrate with the ITO bottom electrode into the reaction chamber of the atomic layer deposition equipment. Use H₂O source and tetrakis(dimethylamino)titanium source as the precursor sources, and deposit for 200 cycles at a temperature of 200 °C to prepare a TiO layer with a thickness of 10 nm. x Layer. Among them, for the O-High optoelectronic memristor to prepare the TiO x layer, introduce tetrakis(dimethylamino)titanium source for 25 ms and H₂O source for 20 ms in each cycle. For the O-Low optoelectronic memristor to prepare the TiO x layer, introduce tetrakis(dimethylamino)titanium source for 25 ms and H₂O source for 5 ms in each cycle; The introduction speeds of the H₂O source and the tetrakis(dimethylamino)titanium source are the same;

[0066] Use H₂O source and tetrakis(dimethylamino)tin source as the precursor sources, and deposit for 60 cycles at a temperature of 200 °C to prepare a SnO₂ layer with a thickness of 3 nm. Introduce tetrakis(dimethylamino)tin source for 25 ms and H₂O source for 20 ms in each cycle; The introduction speeds of the H₂O source and the tetrakis(dimethylamino)tin source are the same.

[0067] (4) Prepare the ITO top electrode

[0068] On the sample deposited with the TiO x / SnO₂ memristive functional layer, make the pattern of the separated top electrode through the mask template, and then put the sample into the reaction chamber of the magnetron sputtering equipment. Use 50W AC power to ionize Ar₂ to make it glow and bombard the ITO target to generate sputtering. The gas flow rate during the preparation process is 5 sccm, and carry out the preparation for 900 s to prepare an ITO layer with a thickness of 60 nm to obtain the separated top electrode. Finally, obtain two optoelectronic memristive devices - O-High and O-Low. These two devices are the same in other aspects, only the oxygen content of the TiO x layer is different.

[0069] Use the B1500A semiconductor device analyzer and the probe station to test the light response characteristics of the two devices, such as Figure 5As shown, (a) shows the change values of the read current of the O-High device and the O-Low device under laser irradiation at 8 s, 40 mW, and different wavelengths (360 nm, 520 nm, 638 nm); (b) shows the change values of the read current of the O-High device and the O-Low device under laser irradiation at 8 s, 638 nm wavelength, and different optical powers (20 - 60 mW); (c) shows the change values of the read current of the O-High device and the O-Low device under laser irradiation at 40 mW, 638 nm wavelength, and different illumination durations (2 s - 20 s); the above read voltages are all set to -0.3 V. From Figure 5 As can be seen from (a), both the O-High device and the O-Low device are most sensitive to 638 nm red light and have the strongest light response, and have no response under 520 nm green light and 360 nm ultraviolet light. Moreover, the light response of the O-Low device is stronger than that of the O-High device; from Figure 5 As can be seen from (b), the light response amplitudes of both the O-High device and the O-Low device increase with the increase of the optical power, and the light response of the O-Low device is stronger than that of the O-High device; from Figure 5 As can be seen from (c), the light response amplitudes of both the O-High device and the O-Low device increase with the increase of the illumination time, and the light response of the O-Low device is stronger than that of the O-High device; the above shows that under the same illumination conditions, the light response speed of the O-Low device is faster than that of the O-High device.

[0070] As can be seen from the above experiments, compared with Example 2, the performance regulation of the optoelectronic memristor with the structure of Example 1 is more obvious and the performance is more excellent. Specifically manifested as:

[0071] 1. The device of Example 1 requires a smaller turn-on light intensity. The device of Example 1 only needs 5 mW of ultraviolet light to generate a photocurrent response (as shown in Figure 4 b), while the device of Example 2 requires more than 20 mW of red light to generate a photocurrent response (as shown in Figure 5 b).

[0072] 2. The device of Example 1 has a light response in both the ultraviolet and green light bands (as shown in Figure 4 a), while the device of Example 2 only has a light response in the red light band (as shown in Figure 5 a). The light response band of the device of Example 1 is wider.

[0073] 3. In the memristor with the structure of Example 1, the average light response speed of O-Low is increased by 400% compared with O-High (as shown in Figure 4 ), while in the memristor with the structure of Example 2, the average light response speed of O-Low is only increased by 90% compared with O-High (as shown in Figure 5 ).

Claims

1. A method for regulating the optoelectronic response rate of an optoelectronic memristor, characterized in that: The optoelectronic memristor includes a bottom electrode, a memristive functional layer, and a top electrode. The memristive functional layer is a bilayer structure. The memristive functional layer 1 close to the bottom electrode is a metal oxide layer with adjustable oxygen vacancies, and the memristive functional layer 2 close to the top electrode is a metal oxide layer. The optoelectronic response rate of the optoelectronic memristor is regulated by adjusting the structure and oxygen vacancy content of the memristive functional layer.

2. The method according to claim 1, characterized in that: The memristive functional layer 1 is an HfO x layer or a TiO x layer, where x ≤ 2; the memristive functional layer 2 is a TiO2 layer or a SnO2 layer.

3. The method according to claim 1 or 2, characterized in that: The memristive functional layer is prepared by atomic layer deposition. Using water as the precursor source of oxygen, when the memristive functional layer 1 is formed by atomic layer deposition, the molar ratio of oxygen to metal is regulated to form metal oxide layers with different oxygen vacancy contents.

4. A photoelectric memristor, characterized in that: It includes a bottom electrode, a memristive functional layer, and a top electrode from bottom to top. The memristive functional layer is a bilayer structure. The memristive functional layer 1 close to the bottom electrode is a metal oxide layer with adjustable oxygen vacancies, and the memristive functional layer 2 close to the top electrode is a metal oxide layer.

5. The optoelectronic memristor according to claim 4, characterized in that: The memristive functional layer 1 is an HfO x layer or a TiO x layer, where x ≤ 2; the memristive functional layer 2 is a TiO2 layer or a SnO2 layer; preferably, the thickness of the memristive functional layer 1 is 5 - 10 nm, and the thickness of the memristive functional layer 2 is 3 - 5 nm.

6. The optoelectronic memristor according to claim 4 or 5, characterized in that: The memristive functional layer is prepared by atomic layer deposition; preferably, when preparing the HfO x layer, H2O source and hafnium tetrakis(dimethylamino) source are used as precursor sources, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form the HfO x layer; when preparing the TiO x layer or TiO2 layer, H2O source and titanium tetrakis(dimethylamino) source are used as precursor sources, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form the TiO x layer or TiO2 layer; when preparing the SnO2 layer, H2O source and tin tetrakis(dimethylamino) source are used as precursor sources, and multiple atomic layer deposition cycles are carried out at a temperature of 200 - 250 °C to form the SnO2 layer.

7. The optoelectronic memristor according to claim 6, characterized in that: Preparation of HfO x layer or TiO x layer, the pulse duration of the H2O source for each deposition cycle is 5 - 20 ms, and the pulse duration of the hafnium tetrakis(dimethylamino) source or titanium tetrakis(dimethylamino) source is 25 - 35 ms; When preparing the TiO2 layer or the SnO2 layer, the pulse duration of the H2O source in each deposition cycle is 25 - 35 ms, and the pulse duration of the titanium tetrakis(dimethylamino) source or the tin tetrakis(dimethylamino) source is 25 - 35 ms.

8. The optoelectronic memristor according to claim 4, characterized in that: The material of the bottom electrode is ITO or TiN, and the material of the top electrode is ITO; preferably, the thickness of the bottom electrode is 70 - 100 nm, and the thickness of the top electrode is 50 - 70 nm.

9. The optoelectronic memristor according to claim 4, characterized in that: It further includes a substrate. The material of the substrate is a p-type Si substrate. The resistivity range of the substrate is 0.002 - 0.004 Ω·cm, and the thickness of the substrate is 400 - 600 nm.

10. The preparation method of the optoelectronic memristor according to claim 5, characterized in that It includes the following steps: (1) Put the cleaned substrate into the reaction chamber of the magnetron sputtering equipment, and obtain the bottom electrode through magnetron sputtering. (2) Put the substrate with the bottom electrode into the reaction chamber of the atomic layer deposition equipment. Using the H2O source, the hafnium tetrakis(dimethylamino) source or the titanium tetrakis(dimethylamino) source as the precursor source, deposit for multiple cycles at a temperature of 200 - 250 °C to obtain the memristive functional layer 1. The pulse duration of the H2O source in each cycle is 5 - 20 ms, and the pulse duration of the hafnium tetrakis(dimethylamino) source or the titanium tetrakis(dimethylamino) source is 25 - 35 ms; using the H2O source, the titanium tetrakis(dimethylamino) source or the tin tetrakis(dimethylamino) source as the precursor source, deposit for multiple cycles at a temperature of 200 - 250 °C to obtain the memristive functional layer 2. The pulse duration of the H2O source in each cycle is 25 - 35 ms, and the pulse duration of the titanium tetrakis(dimethylamino) source or the tin tetrakis(dimethylamino) source is 25 - 35 ms. (3) Cover a patterned mask on the memristive functional layer, and then put it into the reaction chamber of the magnetron sputtering equipment to obtain the top electrode through magnetron sputtering.

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