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CN-122002920-A - Multimode photoelectric synaptic device design and operation method based on asymmetric structure and defect cooperation

CN122002920ACN 122002920 ACN122002920 ACN 122002920ACN-122002920-A

Abstract

The invention discloses a multimode photoelectric synaptic device design and operation method based on the cooperation of an asymmetric structure and defects, which comprises the steps of constructing a device with two asymmetric ends, wherein the structure is a metal layer/a functional layer 1/a functional layer 2/an electrode, and the core is that two asymmetric end functional junctions of a Schottky junction/a heterojunction are required to be formed at two sides of the functional layer 1. The invention utilizes unified but differentiated response dynamics (migration and recombination) of defects such as oxygen vacancies in the functional layer to light and electric signals, realizes the response of specific coded light and electric signals within the next order of magnitude in a single device, and can realize the weighted fusion, nonvolatile storage and selective decoupling of multi-mode signals. The method is independent of a specific material system (comprising oxide types, electrode types, doping or not and the like) and a preparation process, and provides core operation logic for constructing general neuromorphic hardware capable of executing in-situ sensing calculation.

Inventors

  • LV BIN
  • YE JIAHAO

Assignees

  • 浙江大学

Dates

Publication Date
20260508
Application Date
20260408

Claims (10)

  1. 1. A design and operation method of a multimode photoelectric synaptic device based on the cooperation of an asymmetric structure and defects is characterized by comprising the steps of constructing a device with two asymmetric ends, wherein the structure is a metal layer/a functional layer 1/a functional layer 2/an electrode, the functional layer 1 is an oxide film containing defects, the functional layer 2 is an oxide semiconductor film stable at high temperature and high in conductivity, the high temperature is stable at 650 ℃, the conductivity is higher than that of the functional layer 2 by more than 100 times, the functional layer 1 and the metal layer form Schottky contact, the functional layer 2 and the functional layer 1 form heterojunction without rectification characteristics, the functional layer 2 and the electrode are in ohmic contact, and two asymmetric ends of the Schottky junction/the heterojunction are formed on two sides of the functional layer 1.
  2. 2. The method for designing and operating a multimode electro-synaptic device based on the cooperation of an asymmetric structure and a defect according to claim 1, wherein the concentration of oxygen vacancies in the functional layer 1 in defect state is 15-35% of the total concentration of oxygen coordination, the total concentration of oxygen coordination is the sum of the number of oxygen in defect state and the number of oxygen atoms in lattice state, the forbidden bandwidth of the functional layer 1 is larger than that of the functional layer 2, and the thickness is 100-350nm.
  3. 3. The method of claim 1, wherein the metal layer is one or more selected from Au, cu, ni, ti and has a thickness of 10 nm-70 nm.
  4. 4. The method for designing and operating a multimode electro-synaptic device based on cooperation of an asymmetric structure and a defect according to claim 1, wherein the metal layer is grown by physical vapor deposition in an atmosphere with a vacuum degree of < 10 -3 Pa, and the evaporation rate is strictly less than 0.1 nm/s.
  5. 5. The method for designing and operating the multimode photoelectric synaptic device based on the cooperation of the asymmetric structure and the defect according to claim 1, wherein the schottky junction formed by the metal layer and the functional layer 1 in the device is controlled by the defect in the functional layer 1 under the external bias voltage, the nonvolatile response is generated under the optical signal and/or the electric signal, when the device is excited by the optical signal, the defect state in the functional layer 1 captures the photon-generated carrier, the continuous change of the electric conduction is induced, and the migration and the redistribution of the defect can modulate the interface barrier under the excitation of the electric signal, so that the accurate control of the electric conduction state is realized.
  6. 6. The method for designing and operating a multimode photoelectric synaptic device based on the cooperation of an asymmetric structure and a defect according to claim 1, wherein the metal layer is connected with a negative electrode of a power supply, the electrode is connected with a positive electrode of the power supply, an operating voltage is applied to the device to reversely bias the schottky junction, and an electric pulse and an optical pulse are encoded and then applied to the device to realize the multimode signal coupling.
  7. 7. The method of claim 6, wherein the operating voltage is determined based on being able to reverse bias the schottky junction while the current remains <1 nA and the current ripple is less than 5%.
  8. 8. The design and operation method of the multimode photoelectric synaptic device based on the cooperation of the asymmetric structure and the defect according to claim 1 is characterized in that the device can realize programmable decoupling by applying different reverse decoupling voltages after the multimode signals are coupled, and the reverse decoupling voltages are opposite to the working voltages, so that the Schottky junction is positively biased.
  9. 9. The method of designing and operating a multi-modal electro-optic synaptic device based on the cooperation of an asymmetrical structure and a defect as claimed in claim 8, wherein the absolute value of the reverse decoupling voltage applied to the device is greater than the operating voltage at which the nonlinear conductance generated by the electrical input signal to the device is erased.
  10. 10. The method of designing and operating a multimode electro-synaptic device based on the cooperation of an asymmetric structure and a defect as claimed in claim 8, wherein an absolute value of a reverse decoupling voltage applied to the device is less than an operating voltage at which an optical input signal of the device is erased.

Description

Multimode photoelectric synaptic device design and operation method based on asymmetric structure and defect cooperation Technical Field The invention belongs to the field of multimode photoelectric synaptic devices, and relates to a multimode photoelectric synaptic device design and an operation method based on asymmetric structure and defect cooperation. Background With the rapid evolution of artificial intelligence technology, the requirements of mass data processing and real-time perception increase exponentially, and the traditional computing architecture is provided with serious challenges. The current mainstream von neumann architecture generates high energy consumption and delay in the data transmission process due to separation of calculation and storage units, and is difficult to support efficient execution of computation-intensive tasks such as deep learning and the like. In this context, a brain-like computational paradigm inspired by the biological nervous system has developed. The artificial synapse device is used as a core component part thereof, and by simulating the structure and the function of biological synapses, the deep fusion of sensing, storage and calculation is realized, and a possible path is opened for constructing a new generation of high-energy-efficiency computing system. In biological nervous system, synapses are used as connecting hinges among neurons, so that the signal transmission efficiency can be dynamically adjusted according to the stimulus intensity, and parallel processing and distributed storage of information are supported. This mechanism has driven the development of neuromorphic calculations, which significantly improves dynamic information processing efficiency and reduces energy consumption by modeling the recursive network structure of the brain. However, most of the artificial synapse devices are still designed for single-mode signals, and cannot meet the perception requirement of coexistence of multi-source information in a real environment. Therefore, developing an integrated device capable of independently responding and effectively fusing optical, electrical, and other multi-modal signals has become a key to constructing an efficient perception-computing system. The core of the multi-mode fusion is to ensure the normalized matching of different input signals in strength, so that the device can output controllable response meeting the expectations. Although the three-terminal structure device can process multi-mode signals, the structure is complex, and the integration level and the energy efficiency are limited. Under ideal conditions, the two-end structure can complete multi-mode sensing and preliminary processing in a single device, but most of the memristors at two ends are difficult to realize effective decoupling and low coupling fusion between signals at present, so that the practical application of the memristors in a multi-mode sensing system is restricted. In various sensing modes, light signal sensing, particularly ultraviolet light detection, has important application prospects. Ultraviolet light has potential in the fields of automatic driving, biological identification and the like by virtue of strong anti-interference capability. Many oxide semiconductor materials are well suited for photodetection or synaptic responses in terms of their band structure and manner of optical response. Meanwhile, through oxygen defect regulation and control, oxygen vacancies in the material can induce continuous photoconductive effect, so that the dynamic response characteristic of biological synapses is effectively simulated, and an ideal platform is provided for constructing photoelectric synapse devices. However, optical or electrical stimulation of electrical conductance is typically only achieved with a single device for non-volatile enhancement in a single state, while complete synaptic plasticity requires reversible inhibition of electrical conductance by multiple electrical signals. In the prior art, the multi-terminal structure is relied on to assist the electric signal to assist in realizing the inhibition process, so that the complexity and the energy consumption of the system are increased. Therefore, developing a two-terminal structure device capable of achieving conduction multi-mode regulation by an optical signal or an electrical signal has become an important challenge of current research. How to combine the contact engineering and defect regulation and control to realize the effective decoupling and functional fusion of the optical signal and the electrical signal in a cooperative way still needs to be deeply explored. The breakthrough of the problem can powerfully push the development of the multi-mode nerve morphology perception calculation, and lay a foundation for constructing a more efficient and self-adaptive artificial perception system. Disclosure of Invention Based on the urgent demands of the current artificial intelligence technol