Quantum dot enhanced flexible low power consumption neural synapse device and preparation method thereof

Abstract

The application discloses a quantum dot enhanced flexible low-power-consumption neural synapse device and a preparation method thereof. The quantum dot enhanced flexible low-power-consumption neural synapse device comprises a flexible substrate, a bottom electrode formed on the flexible substrate, a two-dimensional semiconductor quantum dot layer formed on the bottom electrode, an organic ferroelectric layer formed on the two-dimensional semiconductor quantum dot layer, a two-dimensional semiconductor quantum dot layer formed on the organic ferroelectric layer, and a top electrode formed on the two-dimensional semiconductor quantum dot layer. Excitation is applied to the top electrode by using an electrical pulse as an input signal source, polarization inversion of the organic ferroelectric layer is realized under regulation and control of a local electric field of the quantum dot, and low-power-consumption long-term potentiation and inhibition characteristics are obtained.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, specifically to a quantum dot-enhanced flexible low-power neural synapse device and its fabrication method. Background Technology

[0002] Traditional computing systems suffer from the information latency drawbacks of the von Neumann architecture, necessitating the development of a novel in-memory computing architecture to meet the requirements of synchronous information processing and storage. Inspired by the human brain, neural computing has emerged. Since neural computing tasks are inseparable from the information transmission and processing via neural synapses, developing synaptic devices is the first step towards realizing hardware-based neural computing.

[0003] Ferroelectric synaptic devices achieve controllable modulation of weighted states through polarization reversal, simulating the plasticity of neural synapses. However, traditional ferroelectric devices such as BiFeO3, PbTiO3, and emerging hafnium-based ferroelectric materials all require high-temperature growth or annealing processes, which are difficult to meet the fabrication requirements of flexible electronics. Thanks to their excellent flexibility and low-temperature, low-cost fabrication processes, organic ferroelectric materials have gradually been developed and have the potential to be used in the fabrication of flexible neural synaptic devices.

[0004] The power consumption of neural synapses in biological systems is 10 fJ / peak, while the power consumption of most reported electronic neural synapses is concentrated in pJ, which is highly detrimental to reducing power consumption in neuromorphic computing. Therefore, designing suitable material systems and device structures to reduce device power consumption is crucial for the development of flexible neural synapse devices.

[0005] Semiconductor quantum dots, as a novel zero-dimensional material system, possess unique quantum size effects and local electric field manipulation capabilities. They can be integrated into the functional layer of devices to achieve overall performance regulation, and have the potential to limit and define the working area of ​​devices, thus having great application value in reducing the overall power consumption of devices. Summary of the Invention

[0006] This invention discloses a quantum dot-enhanced flexible low-power neural synapse device, comprising: a flexible substrate; a bottom electrode formed on the flexible substrate; a two-dimensional semiconductor quantum dot layer formed on the bottom electrode; an organic ferroelectric layer formed on the two-dimensional semiconductor quantum dot layer; a two-dimensional semiconductor quantum dot layer formed on the organic ferroelectric layer; and a top electrode formed on the two-dimensional semiconductor quantum dot layer. An electrical pulse is used as an input signal source to apply excitation to the top electrode, thereby achieving polarization reversal of the organic ferroelectric layer regulated under the local electric field of the quantum dot, resulting in low-power, long-term enhancement and suppression characteristics.

[0007] In the quantum dot-enhanced flexible low-power neural synapse device of the present invention, the flexible substrate is preferably PET, PEN, PDMS, polyimide, or flexible glass.

[0008] In the quantum dot-enhanced flexible low-power neural synapse device of the present invention, preferably, the two-dimensional semiconductor quantum dot layer is MoS2, WS2, WSe2, ReS2, or BP.

[0009] In the quantum dot-enhanced flexible low-power neural synapse device of the present invention, preferably, the organic ferroelectric layer is P(VDF-TrFE).

[0010] This invention also discloses a method for fabricating a quantum dot-enhanced flexible low-power neural synapse device, comprising the following steps: forming a bottom electrode on a flexible substrate; forming a two-dimensional semiconductor quantum dot layer on the bottom electrode; forming an organic ferroelectric layer on the two-dimensional semiconductor quantum dot layer; forming a two-dimensional semiconductor quantum dot layer on the organic ferroelectric layer; forming a top electrode on the two-dimensional semiconductor quantum dot layer; applying excitation to the top electrode using an electrical pulse as an input signal source to achieve polarization reversal of the organic ferroelectric layer regulated under the local electric field of the quantum dot, thereby obtaining low-power long-term enhancement and suppression characteristics.

[0011] In the method for fabricating the quantum dot-enhanced flexible low-power neural synapse device of the present invention, preferably, the flexible substrate is PET, PEN, PDMS, polyimide, or flexible glass.

[0012] In the method for fabricating the quantum dot-enhanced flexible low-power neural synapse device of the present invention, preferably, the two-dimensional semiconductor quantum dot layer is MoS2, WS2, WSe2, ReS2, or BP.

[0013] In the method for fabricating the quantum dot-enhanced flexible low-power neural synapse device of the present invention, preferably, the step of forming a two-dimensional semiconductor quantum dot layer specifically includes: spreading a two-dimensional semiconductor quantum dot solution on the bottom electrode / organic ferroelectric layer using a spin coating method; spin coating for 30s to 120s using a spin coater at a speed of 1000r / min to 4500r / min; and baking at 50℃ to 150℃ using a hot plate for 5 minutes to 30 minutes to obtain the two-dimensional semiconductor quantum dot layer.

[0014] In the method for fabricating the quantum dot-enhanced flexible low-power neural synapse device of the present invention, preferably, the organic ferroelectric layer is P(VDF-TrFE).

[0015] In the method for fabricating the quantum dot-enhanced flexible low-power neural synapse device of the present invention, preferably, the step of forming an organic ferroelectric layer specifically includes: spin-coating a P(VDF-TrFE) solution onto a two-dimensional semiconductor quantum dot layer at a rotation speed of 1000 r / min to 4000 r / min for 30 s to 120 s; baking on a hot plate at 50°C to 80°C for 5 minutes to 30 minutes to remove the solvent and form a film; and then annealing on a hot plate at 100°C to 180°C for 1 hour to 6 hours to obtain the P(VDF-TrFE) ferroelectric layer.

[0016] Beneficial effects:

[0017] (1) Breaking away from the traditional von Neumann computing architecture, the use of ferroelectric neural synaptic devices with storage and computing functions to process information can greatly reduce the latency caused by hardware transmission and improve the computing efficiency of the system.

[0018] (2) The use of organic ferroelectric materials to prepare flexible neural synapse devices not only has excellent bending resistance, but also has the advantages of low cost and low temperature preparation, making it very suitable for applying the devices to the field of flexible electronics.

[0019] (3) The performance of the device is enhanced by using semiconductor quantum dots, which greatly reduces the energy consumption of the device during the polarization reversal process. This provides an effective method for building neural computing devices with lower energy consumption than biological devices, which is of great significance for low-power brain-like computing systems. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for fabricating quantum dot-enhanced flexible low-power neural synapse devices.

[0021] Figures 2-6 This is a schematic diagram of the structure of each stage in the fabrication method of quantum dot-enhanced flexible low-power neural synapse devices.

[0022] Figure 7 This is a schematic diagram of the operation of a quantum dot-enhanced flexible low-power neural synapse device. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining this invention and are not intended to limit this invention. The described embodiments are merely some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] In the description of this invention, it should be noted that the terms "upper," "lower," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Furthermore, many specific details of the invention, such as the structure, materials, dimensions, processing techniques, and methods of the device, are described below to provide a clearer understanding of the invention. However, as those skilled in the art will understand, the invention may be implemented without adhering to these specific details. Unless specifically indicated below, various parts of the device may be made of materials known to those skilled in the art, or may employ materials with similar functionality developed in the future.

[0026] Figure 1 This is a flowchart illustrating the fabrication method of quantum dot-enhanced flexible, low-power neural synapse devices. (For example...) Figure 1 As shown, the fabrication method of quantum dot-enhanced flexible low-power neural synapse devices includes the following steps:

[0027] In step S1, a flexible polyimide substrate with a thickness of 30 μm to 300 μm is prepared for fabricating quantum dot-enhanced flexible low-power neural synapse devices. The flexible substrate can also be PET, PEN, PDMS, flexible glass, etc.

[0028] In step S2, an Al layer with a thickness of 50 nm to 100 nm is fabricated on the flexible substrate 100 using physical vapor deposition as the bottom electrode 101. Figure 2 As shown. The bottom electrode material can also be Ti, Ni, Pt, Au, etc.

[0029] In step S3, a MoS2 quantum dot solution is coated onto the bottom electrode 101 using spin coating. The coating is then spin-coated at a speed of 1000 r / min to 4500 r / min for 30 to 120 seconds using a spin coater. Finally, the solution is baked on a hot plate at a temperature of 50°C to 150°C for 5 to 30 minutes to obtain the MoS2 quantum dot layer 102. Figure 3 As shown. The materials for the two-dimensional semiconductor quantum dot layer can also be WS2, WSe2, ReS2, BP, etc.

[0030] In step S4, a P(VDF-TrFE) solution is spin-coated onto the MoS2 quantum dot layer 102 at a rotation speed of 1000 r / min to 4000 r / min for 30 s to 120 s. Then, it is baked on a hot plate at a temperature of 50°C to 80°C for 5 min to 30 min to remove the solvent and form a film. Subsequently, it is annealed on a hot plate at a temperature of 100°C to 180°C for 1 hour to 6 hours to obtain the P(VDF-TrFE) ferroelectric layer 103. Figure 4 As shown.

[0031] In step S5, a MoS2 quantum dot solution is spread onto the P(VDF-TrFE) ferroelectric layer 103 using spin coating. The solution is then spin-coated at a speed of 1000 r / min to 4500 r / min for 30 to 120 seconds using a spin coater. Finally, the layer is baked on a hot plate at a temperature of 50°C to 150°C for 5 to 30 minutes to obtain the MoS2 quantum dot layer 104. Figure 5 As shown. The materials for the two-dimensional semiconductor quantum dot layer can also be WS2, WSe2, ReS2, BP, etc.

[0032] In step S6, Au with a thickness of 50nm to 100nm is prepared using physical vapor deposition as the top electrode 105, completing the fabrication of a quantum dot-enhanced flexible low-power neural synapse device, such as... Figure 6 As shown. The top electrode material can also be Al, Ti, Ni, Pt, etc.

[0033] like Figure 6 As shown, the quantum dot-enhanced flexible low-power neural synapse device includes: a flexible substrate 100; a bottom electrode 101 formed on the flexible substrate 100; a two-dimensional semiconductor quantum dot layer 102 formed on the bottom electrode 101; an organic ferroelectric layer 103 formed on the two-dimensional semiconductor quantum dot layer 102; a two-dimensional semiconductor quantum dot layer 104 formed on the organic ferroelectric layer 103; and a top electrode 105 formed on the two-dimensional semiconductor quantum dot layer 104.

[0034] like Figure 7 As shown, an electrical pulse is used as the input signal source to apply excitation to the top electrode 105, thereby realizing the polarization reversal of the organic ferroelectric layer regulated under the local electric field of the quantum dot, and obtaining low-power long-term enhancement and suppression characteristics (LTP / LTD).

[0035] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A quantum dot-enhanced flexible low-power neural synapse device, characterized in that, include: Flexible substrate; A bottom electrode is formed on the flexible substrate; A two-dimensional semiconductor quantum dot layer is formed on the bottom electrode; An organic ferroelectric layer is formed on the two-dimensional semiconductor quantum dot layer; A two-dimensional semiconductor quantum dot layer is formed on the organic ferroelectric layer; The top electrode is formed on the two-dimensional semiconductor quantum dot layer; By using an electrical pulse as the input signal source to apply excitation to the top electrode, polarization reversal of the organic ferroelectric layer regulated under the local electric field of the quantum dot is achieved, resulting in low-power, long-range enhancement and suppression characteristics. The organic ferroelectric layer is P(VDF-TrFE).

2. The quantum dot-enhanced flexible low-power neural synapse device according to claim 1, characterized in that, The flexible substrate is PET, PEN, PDMS, polyimide, or flexible glass.

3. The quantum dot-enhanced flexible low-power neural synapse device according to claim 1, characterized in that, The two-dimensional semiconductor quantum dot layer is MoS2, WS2, WSe2, ReS2, or BP.

4. A method for fabricating a quantum dot-enhanced flexible low-power neural synapse device, characterized in that, include: A bottom electrode is formed on a flexible substrate; A two-dimensional semiconductor quantum dot layer is formed on the bottom electrode; An organic ferroelectric layer is formed on the two-dimensional semiconductor quantum dot layer, wherein the organic ferroelectric layer is P(VDF-TrFE); A two-dimensional semiconductor quantum dot layer is formed on the organic ferroelectric layer; A top electrode is formed on the two-dimensional semiconductor quantum dot layer; By using an electrical pulse as the input signal source to apply excitation to the top electrode, polarization reversal of the organic ferroelectric layer regulated under the local electric field of the quantum dot is achieved, resulting in low-power long-term enhancement and suppression characteristics.

5. The method for fabricating a quantum dot-enhanced flexible low-power neural synapse device according to claim 4, characterized in that, The flexible substrate is PET, PEN, PDMS, polyimide, or flexible glass.

6. The method for fabricating a quantum dot-enhanced flexible low-power neural synapse device according to claim 4, characterized in that, The two-dimensional semiconductor quantum dot layer is MoS2, WS2, WSe2, ReS2, or BP.

7. The method for fabricating a quantum dot-enhanced flexible low-power neural synapse device according to claim 4, characterized in that, The specific steps for forming a two-dimensional semiconductor quantum dot layer include: Two-dimensional semiconductor quantum dot solutions were coated onto the bottom electrode and the organic ferroelectric layer using a spin-coating method. Spin coat using a spin coater at a speed of 1000r / min to 4500r / min for 30s to 120s; Two-dimensional semiconductor quantum dot layers are obtained by baking at 50℃~150℃ for 5 minutes to 30 minutes using a hot plate.

8. The method for fabricating a quantum dot-enhanced flexible low-power neural synapse device according to claim 4, characterized in that, The specific steps for forming an organic ferroelectric layer include: P(VDF-TrFE) solution was spin-coated onto a two-dimensional semiconductor quantum dot layer at a rotation speed of 1000 r / min to 4000 r / min for 30 s to 120 s. Bake on a hot plate at 50℃~80℃ for 5 minutes to 30 minutes to remove solvent and form a film; The material is then annealed on a hot plate and baked at 100°C to 180°C for 1 to 6 hours to obtain a P(VDF-TrFE) ferroelectric layer.

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