Homogeneous optoelectronic reservoir computing system based on nitrogen-doped ge-sb-te material

Abstract

The present application discloses a homogeneous optoelectronic reservoir computing system based on a nitrogen-doped Ge-Sb-Te material. The system of the present application comprises an optoelectronic reservoir layer and a readout layer which are connected to each other; the optoelectronic reservoir layer comprises a plurality of optical synaptic devices based on the nitrogen-doped Ge-Sb-Te material; the optical synaptic devices realize perception of and nonlinear response to an image optical signal on the basis of the photoconductive effect on a single optical pulse and the paired-pulse facilitation effect under dual optical pulses; the readout layer comprises a plurality of electrical synaptic devices based on the nitrogen-doped Ge-Sb-Te material; the electrical synaptic devices realize linear response to and image recognition of an output signal of the optoelectronic reservoir layer on the basis of the linearity and the symmetric long-term potentiation and long-term depression functions. In the system of the present application, the reservoir layer and the readout layer use the devices based on the same material, thereby realizing the homogeneous optoelectronic reservoir computing system and higher system integration and process compatibility.

Description

Computing system of homogeneous photoelectric storage cell based on nitrogen-doped Ge-Sb-Te material Technical Field

[0001] The present application belongs to the field of micro-nanoelectronic technology, and more specifically, relates to a homogeneous photoelectric storage pool computing system based on nitrogen-doped Ge-Sb-Te material. Background Art

[0002] The visual system is the most important sensory system in humans. Vision accounts for the vast majority of the information we receive from the outside world and can powerfully influence our cognition, decision-making, emotions, and even subconscious activities. Therefore, developing electronic devices with visual capabilities is a key step towards achieving biomimetic functions.

[0003] In traditional machine vision systems, visual information is captured by image sensors and converted into digital signals for use by storage units and subsequent computing units. The separation of processors and memory in traditional computing units based on the von Neumann architecture results in significant latency and energy consumption during matrix multiplication, hindering latency-sensitive applications such as self-driving cars, robotics, and industrial manufacturing, and making it difficult to meet the demands of real-time interactive systems. Replacing the von Neumann architecture with an integrated storage and computing architecture requires additional digital-to-analog converters (DACs). Furthermore, the transmission of redundant data from the image sensor contributes to high power consumption.

[0004] The human visual system uses sensory neurons to detect analog light signals and perform image preprocessing, followed by further visual signal processing in the visual cortex. This fully analog processing and reduced data movement achieve low latency and high energy efficiency. Inspired by this, artificial neural networks based on this optoelectronic neuromorphic architecture offer the advantages of in-sensor and in-memory computing, further improving the perception and signal processing efficiency of machine vision. Among various artificial neural network architectures, reservoir computing offers the advantage of requiring only the readout layer of the network to be trained and has proven suitable for processing complex spatiotemporal data with minimal training costs. The reservoir computing architecture comprises a reservoir layer and a readout layer. Due to the distinct functions of the reservoir layer (mapping the input time series signal into a high-dimensional feature space) and the readout layer (simple linear processing), currently proposed optoelectronic reservoir computing systems use different materials for the reservoir and readout layers, respectively. This poses challenges to system integration and process compatibility.

[0005] Summary of the Invention

[0006] In response to the above-mentioned defects or improvement needs of the prior art, the present application provides a homogeneous photoelectric reservoir computing system based on nitrogen-doped Ge-Sb-Te material, which aims to solve the technical problem that the materials of the reservoir layer and the readout layer in the existing photoelectric reservoir computing system are different, resulting in low integration and process compatibility.

[0007] To achieve the above objectives, the present application provides a homogeneous photoelectric reservoir computing system based on nitrogen-doped Ge-Sb-Te materials, comprising an interconnected photoelectric reservoir layer and a readout layer;

[0008] The photoelectric reservoir layer includes a plurality of optical synaptic devices based on nitrogen-doped Ge-Sb-Te materials. The optical synaptic devices realize the perception and nonlinear response of image light signals based on the photoconductive effect of a single light pulse and the paired pulse promotion effect under a double light pulse.

[0009] The readout layer includes multiple electrical synaptic devices based on nitrogen-doped Ge-Sb-Te materials. The electrical synaptic devices realize linear response and image recognition of the output signal of the photoelectric reservoir layer based on linearity, symmetry long-term enhancement function and long-term inhibition function.

[0010] Preferably, the optical synapse device includes a photosensitive layer, a left electrode layer and a right electrode layer; the left electrode layer and the right electrode layer are formed on the photosensitive layer and are parallel to each other; the thickness of the photosensitive layer is 5nm to 500nm, and the thickness of the left electrode layer and the right electrode layer is 3nm to 500nm; the spacing between the left electrode layer and the right electrode layer is 1um to 500um.

[0011] Preferably, the left electrode layer and the right electrode layer are made of Al, Ag, Cu, Ti3W7, Pt, Au, W, Ti or TiN.

[0012] Preferably, the photosensitive layer is a nitrogen-doped Ge-Sb-Te material, and its general formula is N x (Ge-Sb-Te) 1-x Wherein the matrix material of Ge-Sb-Te is a compound composed of one or more elements of Ge, Sb and Te, and the nitrogen doping ratio is 0 <x≤10%。

[0013] Preferably, the electrical synapse device includes a lower electrode, an isolation layer, a functional layer and an upper electrode; the isolation layer is located above the lower electrode, a through hole is opened inside the isolation layer, and the through hole is filled with the functional layer; the functional layer is located between the lower electrode and the upper electrode; the thickness of the upper electrode and the lower electrode is 5nm to 500nm, the thickness of the functional layer is 5nm to 500nm, the thickness of the isolation layer is 5nm to 500nm, and the radius of the through hole of the isolation layer is 5nm to 1000nm.

[0014] Preferably, the material of the upper electrode and the lower electrode is Al, Ag, Cu, Ti3W7, Pt, Au, W, Ti or TiN.

[0015] Preferably, the isolation layer material is Si3N4, SiO2, SiC or (ZnS) y (SiO2) 100-y , where y is an integer greater than 0 and less than 100.

[0016] Preferably, the functional layer is a nitrogen-doped Ge-Sb-Te material, and its general formula is N z (Ge-Sb-Te) 1-z ; Wherein the matrix material of Ge-Sb-Te is a compound composed of one or more elements of Ge, Sb and Te, and the nitrogen doping ratio is 0 <z≤10%。

[0017] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies:

[0018] (1) Compared with the traditional machine vision system with separated sensing, storage and computing, this application adopts a biomimetic approach to achieve the visual function similar to that of an organism, and uses a photoelectric storage pool computing system to realize the detection of light signals and the recognition and processing of information, which has the technical advantages of low latency and high energy efficiency;

[0019] (2) Compared with the existing heterogeneous reservoir computing system, the photoelectric reservoir computing system of the present application uses devices based on the same material for both the reservoir layer and the readout layer, thus realizing a homogeneous photoelectric reservoir computing system with higher system integration and process compatibility;

[0020] (3) The present application uses nitrogen-doped Ge-Sb-Te materials to prepare optical synaptic devices and electrical synaptic devices, respectively. The optical synaptic device based on nitrogen-doped Ge-Sb-Te materials has a photoconductive effect for a single light pulse and a paired pulse facilitation effect under a double light pulse, thereby realizing the perception and processing functions of image signals; the electrical synaptic device based on nitrogen-doped Ge-Sb-Te materials has high linearity and high symmetry long-term potentiation (LTP) and long-term depression (LTD) functions, thereby realizing the storage and calculation of the output signal of the photoelectric storage pool layer; compared with the existing synaptic devices based on sulfur compounds, the physical properties are richer and the functions realized are more comprehensive. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic structural diagram of an N-Ge1Sb4Te7 optical synapse device provided in an embodiment of the present application;

[0022] FIG2 is a time-dependent normalized photoresponse curve of the N-Ge1Sb4Te7 optical synaptic device under light stimulation provided in an embodiment of the present application;

[0023] FIG3 is a diagram showing the paired pulse promotion effect of the N-Ge1Sb4Te7 optical synapse device under double pulses provided in an embodiment of the present application;

[0024] FIG4 is a schematic structural diagram of an electrical synapse device provided in an embodiment of the present application;

[0025] FIG5 is a graph showing long-term potentiation / depression measurements of an N-Ge1Sb4Te7 electrical synaptic device according to an embodiment of the present application;

[0026] FIG6 is a schematic diagram of a computing system for a homogeneous photoelectric storage cell based on N-Ge1Sb4Te7 provided in an embodiment of the present application;

[0027] 7 is a schematic diagram showing how the recognition accuracy of the N-Ge1Sb4Te7 homogeneous photoelectric storage pool computing system provided in an embodiment of the present application varies with the number of training iterations;

[0028] In all drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. photosensitive layer; 2. left electrode layer; 3. right electrode layer; 4. substrate; 5. lower electrode; 6. isolation layer; 7. functional layer; 8. upper electrode. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0030] It should be understood that in the description of this application, the terms "upper," "lower," "vertical," "horizontal," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In addition, many specific details of this application are described below, such as the device structure, materials, dimensions, processing techniques, and technologies, to facilitate a clearer understanding of this application. However, as will be appreciated by those skilled in the art, this application may be implemented without following these specific details. Unless otherwise noted below, various components of the device may be constructed from materials known to those skilled in the art, or materials with similar functions developed in the future may be used.

[0032] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0033] Next, the technical solutions provided in the embodiments of this application are introduced.

[0034] Example 1A:

[0035] Example 1A of the present application provides an N-Ge1Sb4Te7 optical synapse device, and the specific preparation process is as follows:

[0036] 1. Select a SiO2 / Si(100) substrate with a size of 1 cm×1 cm as the substrate, clean the surface and back surface, and remove dust particles, organic and inorganic impurities; specifically:

[0037] a) placing the substrate in an acetone solution and vibrating it with ultrasonic power of 40 W for 10 minutes, followed by rinsing with deionized water;

[0038] b) the acetone-treated substrate was subjected to ultrasonic vibration at a power of 40 W for 10 minutes in an ethanol solution, rinsed with deionized water, and blown dry with high-purity N2 gas on the surface and back to obtain a substrate to be sputtered;

[0039] 2. An N-doped Ge1Sb4Te7 photosensitive layer 1 is prepared by magnetron sputtering. A Ge1Sb4Te7 alloy target is selected as the target material, and sputtering is performed using a DC power supply. During the sputtering process, the thickness of the N-doped Ge1Sb4Te7 photosensitive layer 1 can be adjusted by adjusting the sputtering power and sputtering time. In this embodiment, N2:Ar=3:40 (doping concentration of 0.92%), a total gas pressure of 0.5 Pa, a power of 30 W, and a sputtering time of 300 s are used. The thickness of the prepared photosensitive layer 1 is 100 nm.

[0040] 3. Prepare the patterns of the left electrode layer 2 and the right electrode layer 3 on the photosensitive layer 1 by photolithography, and prepare the pattern mask layers of the left electrode layer 2 and the right electrode layer 3 by the processes of coating, pre-baking, pre-exposure, post-baking, post-exposure, and development;

[0041] 4. Take the photolithographic sample and use the sputtering process to prepare the left electrode layer 2 and the right electrode layer 3; the sputtering power is 40W, the argon ambient pressure is 0.5Pa, and the DC sputtering is performed for 700s to obtain 100nm thick W electrodes as the left electrode layer 2 and the right electrode layer 3; the spacing between the left electrode layer and the right electrode layer is 100um;

[0042] 5. Take the samples prepared by sputtering the left electrode layer 2 and the right electrode layer 3, soak them in acetone solution for 30 minutes, peel off the pattern mask layers of the left electrode layer 2 and the right electrode layer 3, then wash them with ethanol and deionized water, and blow dry them with a nitrogen gun to obtain the patterned left electrode layer 2 and the right electrode layer 3.

[0043] After completing the above steps, the preparation of the N-Ge1Sb4Te7 optical synapse device is completed, and the device structure is shown in Figure 1.

[0044] Example 1B:

[0045] Example 1B of the present application provides an N-Ge1Sb4Te7 optical synapse device, and the specific preparation process is as follows:

[0046] 1. Select a SiO2 / Si(100) substrate with a size of 1 cm×1 cm as the substrate, clean the surface and back surface, and remove dust particles, organic and inorganic impurities; specifically:

[0047] a) placing the substrate in an acetone solution and vibrating it with ultrasonic power of 40 W for 10 minutes, followed by rinsing with deionized water;

[0048] b) the acetone-treated substrate was subjected to ultrasonic vibration at a power of 40 W for 10 minutes in an ethanol solution, rinsed with deionized water, and blown dry with high-purity N2 gas on the surface and back to obtain a substrate to be sputtered;

[0049] 2. The N-doped Ge1Sb4Te7 photosensitive layer 1 is prepared by magnetron sputtering. The target material is a Ge1Sb4Te7 alloy target. The sputtering is performed using a DC power supply. During the sputtering process, the thickness of the N-doped Ge1Sb4Te7 photosensitive layer 1 can be adjusted by adjusting the sputtering power and sputtering time. In this embodiment, N2:Ar=1:40 (doping concentration of 0.1%), a total gas pressure of 0.5 Pa, a power of 30 W, and a sputtering time of 30 s are used. The thickness of the prepared photosensitive layer 1 is 5 nm.

[0050] 3. Prepare the patterns of the left electrode layer 2 and the right electrode layer 3 on the photosensitive layer 1 by photolithography, and prepare the pattern mask layers of the left electrode layer 2 and the right electrode layer 3 by the processes of coating, pre-baking, pre-exposure, post-baking, post-exposure, and development;

[0051] 4. Take the photolithographic sample and use the sputtering process to prepare the left electrode layer 2 and the right electrode layer 3; the sputtering power is 40W, the argon ambient pressure is 0.5Pa, and the DC sputtering is performed for 50s to obtain 3nm thick W electrodes as the left electrode layer 2 and the right electrode layer 3; the spacing between the left electrode layer and the right electrode layer is 1um;

[0052] 5. Take the samples prepared by sputtering the left electrode layer 2 and the right electrode layer 3, soak them in acetone solution for 30 minutes, peel off the pattern mask layers of the left electrode layer 2 and the right electrode layer 3, then wash them with ethanol and deionized water, and blow dry them with a nitrogen gun to obtain the patterned left electrode layer 2 and the right electrode layer 3.

[0053] Example 1C:

[0054] Example 1C of the present application provides an N-Ge1Sb4Te7 optical synapse device, and the specific preparation process is as follows:

[0055] 1. Select a SiO2 / Si(100) substrate with a size of 1 cm×1 cm as the substrate, clean the surface and back surface, and remove dust particles, organic and inorganic impurities; specifically:

[0056] a) placing the substrate in an acetone solution and vibrating it with ultrasonic power of 40 W for 10 minutes, followed by rinsing with deionized water;

[0057] b) the acetone-treated substrate was subjected to ultrasonic vibration at a power of 40 W for 10 minutes in an ethanol solution, rinsed with deionized water, and blown dry with high-purity N2 gas on the surface and back to obtain a substrate to be sputtered;

[0058] 2. An N-doped Ge1Sb4Te7 photosensitive layer 1 is prepared by magnetron sputtering. A Ge1Sb4Te7 alloy target is selected as the target material, and sputtering is performed using a DC power supply. During the sputtering process, the thickness of the N-doped Ge1Sb4Te7 photosensitive layer 1 can be adjusted by adjusting the sputtering power and sputtering time. In this embodiment, N2:Ar=10:40 (doping concentration is 10%), a total gas pressure of 0.5 Pa, a power of 30 W, and a sputtering time of 1200 s are used. The thickness of the prepared photosensitive layer 1 is 500 nm.

[0059] 3. Prepare the patterns of the left electrode layer 2 and the right electrode layer 3 on the photosensitive layer 1 by photolithography, and prepare the pattern mask layers of the left electrode layer 2 and the right electrode layer 3 by the processes of coating, pre-baking, pre-exposure, post-baking, post-exposure, and development;

[0060] 4. Take the sample after photolithography and use the sputtering process to prepare the left electrode layer 2 and the right electrode layer 3; the sputtering power is 40W, the argon ambient pressure is 0.5Pa, and the DC sputtering is performed for 2500s to obtain 500nm thick W electrodes as the left electrode layer 2 and the right electrode layer 3; the spacing between the left electrode layer and the right electrode layer is 500um;

[0061] 5. Take the samples prepared by sputtering the left electrode layer 2 and the right electrode layer 3, soak them in acetone solution for 30 minutes, peel off the pattern mask layers of the left electrode layer 2 and the right electrode layer 3, then wash them with ethanol and deionized water, and blow dry them with a nitrogen gun to obtain the patterned left electrode layer 2 and the right electrode layer 3.

[0062] Example 2:

[0063] In Example 2 of the present application, a photoelectric testing system is used to test the optical performance of the N-Ge1Sb4Te7 optical synapse device;

[0064] Figure 2 shows the time-dependent normalized photoresponse curve of the N-Ge1Sb4Te7 optical synaptic device under light pulse stimulation, as provided in an embodiment of the present application. It can be seen that the light pulse stimulation triggers a significant increase in current, which gradually decays within a few seconds after the stimulation is removed. This demonstrates that the N-Ge1Sb4Te7 optical synaptic device exhibits a significant photoconductive effect.

[0065] Figure 3 illustrates the paired-pulse facilitation effect of a double-pulse N-Ge1Sb4Te7 optical synaptic device, provided in an embodiment of the present application. In Figure 3, the optical pulse width is 200 ms, and the interval between the two optical pulses is 200 ms. When two optical pulses are sequentially applied to the N-Ge1Sb4Te7 optical synaptic device, the excitatory postsynaptic current of the second optical pulse is higher than that of the first optical pulse due to coupling of excitatory postsynaptic currents caused by the photoconductive effect. This demonstrates the potential of this device to process complex temporal information.

[0066] Example 3A:

[0067] Example 3A of the present application provides an N-Ge1Sb4Te7 electrical synaptic device, and the specific preparation process is as follows:

[0068] 1. Select a SiO2 / Si(100) substrate with a size of 1 cm×1 cm as substrate 4, clean the surface and back surface, and remove dust particles, organic and inorganic impurities; specifically:

[0069] a) placing the substrate 4 in an acetone solution and vibrating it with ultrasonic power of 40 W for 10 minutes, followed by rinsing with deionized water;

[0070] b) The acetone-treated substrate 4 was subjected to ultrasonic vibration at a power of 40 W for 10 minutes in an ethanol solution, rinsed with deionized water, and blown dry with high-purity N2 gas on the surface and back to obtain a substrate to be sputtered;

[0071] 2. A Pt electrode with a thickness of 100 nm was prepared as the lower electrode 5 by a DC power supply sputtering method;

[0072] 3. Using chemical vapor deposition, SiO2 with a thickness of 100 nm is deposited on the Pt lower electrode 5 in step 2 to obtain an isolation layer 6.

[0073] 4. Through electron beam lithography and etching processes, a through hole with a depth of 100 nm and a radius of 125 nm is formed in the isolation layer 6 in step 3.

[0074] 5. Form an upper electrode 8 square pattern array through an overlay process.

[0075] 6. The N-doped Ge1Sb4Te7 functional layer 7 is prepared by magnetron sputtering. The target material is a Ge1Sb4Te7 alloy target. A DC power supply is used for sputtering. The thickness of the N-doped Ge1Sb4Te7 functional layer 7 can be adjusted by adjusting the sputtering power and sputtering time during the sputtering process. In this embodiment, N2:Ar=3:40 (doping concentration of 0.92%), a total gas pressure of 0.5 Pa, a power of 30 W, and a sputtering time of 300 s are used. The thickness of the prepared N-doped Ge1Sb4Te7 functional layer 7 is 100 nm.

[0076] 7. A Pt electrode with a thickness of 100 nm was prepared as the upper electrode 8 using a DC power sputtering method.

[0077] After completing the above steps, an array of N-Ge1Sb4Te7 electrical synaptic devices was obtained on the sample. The device structure is shown in Figure 4.

[0078] Example 3B:

[0079] Example 3 of the present application provides an N-Ge1Sb4Te7 electrical synaptic device, and the specific preparation process is as follows:

[0080] 1. Select a SiO2 / Si(100) substrate with a size of 1 cm×1 cm as substrate 4, clean the surface and back surface, and remove dust particles, organic and inorganic impurities; specifically:

[0081] a) placing the substrate 4 in an acetone solution and vibrating it with ultrasonic power of 40 W for 10 minutes, followed by rinsing with deionized water;

[0082] b) The acetone-treated substrate 4 was subjected to ultrasonic vibration at a power of 40 W for 10 minutes in an ethanol solution, rinsed with deionized water, and blown dry with high-purity N2 gas on the surface and back to obtain a substrate to be sputtered;

[0083] 2. A Pt electrode with a thickness of 5 nm was prepared as the lower electrode 5 by a DC power supply sputtering method;

[0084] 3. Using chemical vapor deposition, SiO2 with a thickness of 5 nm is deposited on the Pt lower electrode 5 in step 2 to obtain an isolation layer 6.

[0085] 4. Through electron beam lithography and etching processes, a through hole with a depth of 5 nm and a radius of 5 nm is formed in the isolation layer 6 in step 3.

[0086] 5. Form an upper electrode 8 square pattern array through an overlay process.

[0087] 6. The N-doped Ge1Sb4Te7 functional layer 7 is prepared by magnetron sputtering. The target material is a Ge1Sb4Te7 alloy target. A DC power supply is used for sputtering. The thickness of the N-doped Ge1Sb4Te7 functional layer 7 can be adjusted by adjusting the sputtering power and sputtering time during the sputtering process. In this embodiment, N2:Ar=1:40 (doping concentration is 0.1%), the total gas pressure is 0.5 Pa, the power is 30 W, and the sputtering time is 30s. The thickness of the prepared N-doped Ge1Sb4Te7 functional layer 7 is 5nm.

[0088] 7. A Pt electrode with a thickness of 5 nm was prepared as the upper electrode 8 using a DC power sputtering method.

[0089] Example 3C:

[0090] Example 3 of the present application provides an N-Ge1Sb4Te7 electrical synaptic device, and the specific preparation process is as follows:

[0091] 1. Select a SiO2 / Si(100) substrate with a size of 1 cm×1 cm as substrate 4, clean the surface and back surface, and remove dust particles, organic and inorganic impurities; specifically:

[0092] a) placing the substrate 4 in an acetone solution and vibrating it with ultrasonic power of 40 W for 10 minutes, followed by rinsing with deionized water;

[0093] b) The acetone-treated substrate 4 was subjected to ultrasonic vibration at a power of 40 W for 10 minutes in an ethanol solution, rinsed with deionized water, and blown dry with high-purity N2 gas on the surface and back to obtain a substrate to be sputtered;

[0094] 2. A Pt electrode with a thickness of 500 nm was prepared as the lower electrode 5 by a DC power supply sputtering method;

[0095] 3. Using chemical vapor deposition, SiO2 with a thickness of 500 nm is deposited on the Pt lower electrode 5 in step 2 to obtain an isolation layer 6.

[0096] 4. Through electron beam lithography and etching processes, a through hole with a depth of 500 nm and a radius of 1000 nm is formed in the isolation layer 6 in step 3.

[0097] 5. Form an upper electrode 8 square pattern array through an overlay process.

[0098] 6. The N-doped Ge1Sb4Te7 functional layer 7 is prepared by magnetron sputtering. The target material is a Ge1Sb4Te7 alloy target. A DC power supply is used for sputtering. The thickness of the N-doped Ge1Sb4Te7 functional layer 7 can be adjusted by adjusting the sputtering power and sputtering time during the sputtering process. In this embodiment, N2:Ar=10:40 (doping concentration is 10%), the total gas pressure is 0.5 Pa, the power is 30 W, and the sputtering is performed for 1200 s. The thickness of the prepared N-doped Ge1Sb4Te7 functional layer 7 is 500 nm.

[0099] 7. A Pt electrode with a thickness of 500 nm was prepared as the upper electrode 8 using a DC power sputtering method.

[0100] Example 4:

[0101] In Example 4 of the present application, long-term potentiation (LTP) / depression (LTD) measurements were performed on an N-Ge1Sb4Te7 electrical synaptic device. As shown in Figure 5 , it can be seen that the shape of the conductance change exhibits good continuity with the number of applied pulses. In Figure 5 , the nonlinearity of the LTP portion obtained by fitting the formula is 3.72, and the nonlinearity of the LTD portion is 2.32, indicating that the conductance regulation of the N-Ge1Sb4Te7 electrical synaptic device is highly linear. In addition, the nonlinearities of both LTP and LTD are positive, indicating that the conductance regulation is highly symmetrical.

[0102] Example 5:

[0103] In Example 5 of the present application, Matlab software was used to construct a homogeneous photoelectric reservoir computing network based on N-Ge1Sb4Te7. Figure 6 shows a schematic diagram of the homogeneous photoelectric reservoir computing system based on N-Ge1Sb4Te7. The characteristics of the optical synaptic device of N-Ge1Sb4Te7 (doping concentration of 0.92%) serve as the reservoir layer in the reservoir computing network, and the characteristics of the electrical synaptic device of N-Ge1Sb4Te7 (doping concentration of 0.92%) serve as the readout layer in the reservoir computing network. The homogeneous photoelectric reservoir computing network based on N-Ge1Sb4Te7 was used to recognize sign language images. The figure shows how the recognition accuracy changes with the number of training iterations. It can be seen that after only 1000 iterations, the accuracy reaches 99.5%, demonstrating the potential of the homogeneous photoelectric reservoir computing network based on N-Ge1Sb4Te7 for practical applications in artificial vision systems.

[0104] The above content is easily understood by those skilled in the art. The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A homogeneous photoelectric storage cell computing system based on nitrogen-doped Ge-Sb-Te material, characterized in that: including a photoelectric storage layer and a readout layer connected to each other; The photoelectric reservoir layer includes a plurality of optical synaptic devices based on nitrogen-doped Ge-Sb-Te materials. The optical synaptic devices realize the perception and nonlinear response of image light signals based on the photoconductive effect of a single light pulse and the paired pulse promotion effect under a double light pulse. The readout layer includes multiple electrical synaptic devices based on nitrogen-doped Ge-Sb-Te materials. The electrical synaptic devices realize linear response and image recognition of the output signal of the photoelectric reservoir layer based on linearity, symmetry long-term enhancement function and long-term inhibition function.

2. The system according to claim 1, wherein: The optical synapse device includes a photosensitive layer, a left electrode layer and a right electrode layer; the left electrode layer and the right electrode layer are formed on the photosensitive layer and are parallel to each other; the thickness of the photosensitive layer is 5nm to 500nm, and the thickness of the left electrode layer and the right electrode layer is 3nm to 500nm; the spacing between the left electrode layer and the right electrode layer is 1um to 500um.

3. The system according to claim 2, characterized in that The left electrode layer and the right electrode layer are made of Al, Ag, Cu, Ti3W7, Pt, Au, W, Ti or TiN.

4. The system according to claim 2, wherein: The photosensitive layer is a nitrogen-doped Ge-Sb-Te material, and its general formula is N x (Ge-Sb-Te) 1-x ; Wherein the matrix material of Ge-Sb-Te is a compound composed of one or more elements of Ge, Sb and Te, and the nitrogen doping ratio is 0 <x≤10%。 5. The system according to claim 1, wherein: The electrical synapse device includes a lower electrode, an isolation layer, a functional layer and an upper electrode; the isolation layer is located above the lower electrode, and a through hole is opened inside the isolation layer, and the through hole is filled with the functional layer; the functional layer is located between the lower electrode and the upper electrode; the thickness of the upper electrode and the lower electrode is 5nm to 500nm, the thickness of the functional layer is 5nm to 500nm, the thickness of the isolation layer is 5nm to 500nm, and the radius of the through hole of the isolation layer is 5nm to 1000nm.

6. The system according to claim 5, characterized in that The materials of the upper electrode and the lower electrode are Al, Ag, Cu, Ti3W7, Pt, Au, W, Ti or TiN.

7. The system according to claim 5, characterized in that The isolation layer material is Si3N4, SiO2, SiC or (ZnS) y (SiO2) 100-y , where y is an integer greater than 0 and less than 100.

8. The system according to claim 5, wherein: The functional layer is a nitrogen-doped Ge-Sb-Te material, and its general formula is N z (Ge-Sb-Te) 1-z ; Wherein the matrix material of Ge-Sb-Te is a compound composed of one or more elements of Ge, Sb and Te, and the nitrogen doping ratio is 0 <z≤10%。

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