Search

CN-121985607-A - Dynamically adjustable van der Waals heterojunction pulse type event detector

CN121985607ACN 121985607 ACN121985607 ACN 121985607ACN-121985607-A

Abstract

The invention discloses a dynamically adjustable van der Waals heterojunction pulse type event detector, and belongs to the technical field of event detectors. The technical problem to be solved is that the current sensor has limited capability of regulating and controlling time response and pulse characteristics, and the technical scheme is characterized by comprising a substrate layer, an electrode structure and a two-dimensional material heterojunction layer which are sequentially arranged from bottom to top; the electrode structure comprises a source electrode, a drain electrode and a grid electrode, wherein the grid electrode is arranged between the source electrode and the drain electrode, and a two-dimensional material heterojunction layer is arranged on the source electrode and the drain electrode.

Inventors

  • ZHOU JING
  • ZHANG XIANDA
  • LI ZIAO
  • NING JUN
  • BU YONGHAO
  • DENG JIE
  • SHI MENGDIE
  • WANG RUOWEN
  • Cui Tianyuan
  • YE TAO
  • GUO XUELING

Assignees

  • 中国科学院上海技术物理研究所

Dates

Publication Date
20260505
Application Date
20260408

Claims (12)

  1. 1. A dynamically adjustable van der Waals heterojunction pulse type event detector is characterized by comprising a substrate layer, an electrode structure and a two-dimensional material heterojunction layer which are sequentially arranged from bottom to top; the electrode structure comprises a source electrode, a drain electrode and a grid electrode, and the grid electrode is arranged between the source electrode and the drain electrode; A two-dimensional material heterojunction layer is disposed over the source and drain electrodes.
  2. 2. The dynamically tunable van der waals heterojunction pulsed event detector of claim 1, wherein the two-dimensional material heterojunction layer is a layer of molybdenum disulfide and a layer of black phosphorus disposed over the source and drain electrodes, wherein the black phosphorus and molybdenum disulfide are stacked to form a MoS 2 -BP heterojunction.
  3. 3. A dynamically adjustable van der waals heterojunction pulse type event detector as claimed in claim 2, wherein said source and drain electrodes are of equal thickness.
  4. 4. A dynamically adjustable van der waals heterojunction pulse type event detector as claimed in claim 3, wherein a molybdenum disulfide layer is disposed on the source electrode or the drain electrode, and a black phosphorus layer is disposed on the drain electrode or the source electrode, and an end of the black phosphorus layer contacting the molybdenum disulfide layer is disposed under the molybdenum disulfide layer.
  5. 5. A dynamically adjustable van der waals heterojunction pulse type event detector as claimed in claim 1, wherein the substrate layer comprises a base layer of silicon material, and an insulating layer of silicon dioxide material disposed on the base layer.
  6. 6. A dynamically adjustable van der waals heterojunction pulse type event detector as claimed in claim 5, wherein a metal electrode is disposed on said insulating layer.
  7. 7. The dynamically tunable van der waals heterojunction pulse type event detector as claimed in claim 6, wherein said source electrode and said drain electrode are both made of a Ti/Au double-layer metal structure, and said gate electrode is made of Au metal.
  8. 8. The dynamically tunable van der waals heterojunction pulse type event detector as claimed in claim 7, wherein the Ti/Au bi-layer metal structure has a thickness of 10 nm a, a thickness of 90 a nm a thickness of the Au layer, and a thickness of 100 a nm a thickness of the gate electrode.
  9. 9. A dynamically tunable van der waals heterojunction pulse event detector as claimed in claim 2, wherein an isolation layer is provided between the gate and the MoS 2 -BP heterojunction.
  10. 10. The dynamically adjustable van der waals heterojunction pulse type event detector as claimed in claim 9, wherein the black phosphorus layer is disposed at one end on the source electrode or the drain electrode and the other end on the isolation layer, and the corresponding molybdenum disulfide layer is disposed at one end on the drain electrode or the source electrode and the other end on the black phosphorus layer.
  11. 11. A dynamically adjustable van der waals heterojunction pulse type event detector as claimed in claim 9, wherein the isolation layer is comprised of boron nitride.
  12. 12. The dynamically adjustable van der waals heterojunction pulse type event detector as claimed in claim 9, wherein the thickness of the molybdenum disulfide layer is 40nm, the thickness of the black phosphorus layer is 50nm, and the thickness of the isolation layer is 40nm.

Description

Dynamically adjustable van der Waals heterojunction pulse type event detector Technical Field The invention belongs to the technical field of event detectors, and particularly relates to a dynamically adjustable van der Waals heterojunction pulse type event detector. Background With the development of machine vision and neuromorphic calculation, the traditional image sensing mode based on frame reading gradually exposes the problems of large data redundancy, high response delay, high power consumption and the like in a high-speed dynamic scene. Especially in the scene of rapid change of light intensity or high-speed movement of a target, the continuous frame acquisition and the back-end processing are difficult to timely and effectively extract key information. The event type detector outputs signals only when external stimulus changes, so that asynchronous perception of dynamic information is realized, and the event type detector has the advantages of high response speed, small data volume, low power consumption and the like. The existing event type vision system is dependent on a CMOS pixel level circuit to generate pulse event output through a comparison or differential circuit, but has complex structure and limited integration level, and mainly works in a visible light wave band, thereby being unfavorable for expanding to infrared application. In order to reduce the complexity of the system, in-sensor signal processing thought for directly realizing signal preprocessing and dynamic coding at the sensor level is proposed in recent years. Related researches show that by means of transient response of the device or combination of simple electrical structures, pulse or event signals can be directly obtained when light intensity changes, so that back-end calculation burden is reduced. However, existing schemes are mostly based on silicon-based device systems, the response band is limited by the material, and the regulatory capability for time response and pulse characteristics is limited. Comparative document 1: Journal names or book names 2D Materials, literature names Gate tunable MoS 2 -black phosphorusheterojunction devices, volume No. 2D mate 2 (2015) 034009, publication date 2015, i.e., academic papers (Gate tunable molybdenum disulfide-black phosphorus heterojunction device) published in the journal of the authoritative journal of two-dimensional Materials research under the IOP Publishing flag in 2015, which discloses that the heterojunction is the core base unit of modern electronic and optoelectronic devices. The discovery of two-dimensional semiconductors in recent years has provided the possibility to build heterojunctions with atomically sharp interfaces by van der Waals interactions. Molybdenum disulfide (MoS 2) -Black Phosphorus (BP) heterojunction devices were prepared. Since black phosphorus has a narrow band gap and the fermi level is not pinned, the heterojunction can be regulated into two types, p-n junction or n-n junction, by electrostatic gate voltage. Current rectifying behavior was observed in both the p-n junction and the n-n junction. The current rectifying effect of the MoS 2 -BP n-n junction is due to the potential barrier formed at the interface of the wide bandgap MoS 2 and the narrow bandgap BP. The system researches the grid voltage dependence of the forward current, the reverse current and the current rectification characteristic of the heterojunction under different thickness scales, and shows that the electrical property of the heterojunction can be regulated and controlled by designing the thicknesses of the MoS 2 and the BP sheet. In the prior art, research based on a two-dimensional material heterojunction mainly focuses on steady-state photocurrent output, a light intensity change process is difficult to directly characterize, and a pulse output scheme for event type detection is not available. Disclosure of Invention The invention aims to provide a dynamically adjustable van der Waals heterojunction pulse type event detector, which aims to solve the technical problems that the existing sensor is based on a silicon-based device system, the response wave band is limited by materials, and the time response and pulse characteristic regulation and control capability are limited. The invention aims to provide an event type detector based on a van der Waals heterojunction, which utilizes transient electric response generated by a device under external stimulus change, realizes pulse type event output through structure and signal path design, and supports dynamic adjustability of pulse characteristics so as to meet the requirements of infrared event sensing and low-power consumption machine vision application. Description of the terminology: Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the claimed subject matter belongs. All patents, patent inventions, and pub