Method for realizing multi-parameter photoelectric detection based on CrSBr tunneling structure

Abstract

The invention discloses a method for realizing multi-parameter photoelectric detection based on a CrSBr tunneling structure. According to the method, the spin-electron coupling effect in a two-dimensional antiferromagnetic semiconductor CrSBr is utilized, light with different photon energies and polarization degrees is applied to a tunneling structure, stable light current response with extremely high linear dichroism can be obtained, the light current response is effectively regulated and controlled by a magnetic field, and multi-parameter photoelectric detection is achieved. The invention provides an important material platform and research basis for researching a new generation of spinning-electron-optoelectronic devices and sensitive multi-field sensors.

Description

Technical Field

[0001] The present invention relates to the field of spin electronics and optoelectronic detection devices, and in particular to a method for detecting multiple external physical parameters (including photon energy, light polarization and magnetic field) by utilizing a two-dimensional magnetic semiconductor CrSBr tunnel junction through light excitation and external magnetic field regulation. Background Art

[0002] With the continuous advancement of information technology, chip miniaturization has gradually entered the post-Moore era. Exploring and utilizing new degrees of freedom and information transmission methods provide new development opportunities for the innovation of next-generation electronic devices. Since the discovery of graphene, low-dimensional van der Waals material systems have attracted widespread attention in basic physics research and electronic device applications. Two-dimensional semiconductor materials have become one of the key materials for the preparation of various electronic and optoelectronic devices due to their adjustable band gap and high carrier mobility.

[0003] However, the current photoelectric detection technology based on traditional semiconductors has many limitations in terms of multi-parameter regulation. In particular, the intrinsic band structure of these materials is insensitive to the external magnetic field, which means that the magnetic field regulation of most optoelectronic devices requires the use of complex heterostructures or the introduction of defects. This increases the complexity of the system and reduces its operability in practical applications. In addition, existing technologies usually require strong magnetic fields to produce significant photoelectric effect regulation, further limiting the stability and application range of these devices. Therefore, the development of efficient, magnetic field-adjustable multi-degree-of-freedom coupled optoelectronic materials and optoelectronic devices has become an important and challenging topic in the field of spin electronics and optoelectronics. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention proposes a method for realizing multi-parameter photoelectric detection based on the CrSBr tunneling structure. The method utilizes the two-dimensional antiferromagnetic semiconductor material CrSBr to realize the coordinated regulation of photoelectric properties by combining magnetic field, photon energy and polarization degree, providing an important platform for exploring the interaction between magnetic, optical and electrical properties.

[0005] In order to achieve the purpose of the present invention, the present invention provides a multi-parameter photoelectric detection method based on the CrSBr material tunneling structure, and the specific steps include:

[0006] 1) The graphite material, CrSBr material, and graphite material are placed on the Si / SiO 2 On the substrate, a tunnel junction device is obtained;

[0007] 2) Cooling the tunnel junction device to 2K, applying a specific voltage to the tunnel junction device, changing the incident photon energy and power based on a variable wavelength supercontinuum laser, obtaining the photocurrent size and photoresponsivity that vary with the incident photon energy under the voltage, and obtaining the photocurrent-photon energy spectrum;

[0008] 3) changing the polarization angle of the incident light, measuring the "8"-shaped distribution of the photocurrent in step 2 along the polarization angle of the incident light, with the maximum along the b-axis of the CrSBr material lattice and the minimum along the a-axis of the CrSBr material lattice, and dividing the photocurrent-photon energy spectrum of the incident light polarized along the two extreme value directions to obtain the linear dichroism spectrum of the photocurrent;

[0009] 4) Fix the polarization of the incident photon at an angle along the b-axis of the CrSBr material crystal, change the external magnetic field and photon energy, and detect the photocurrent response phase diagram of the magnetic field-photon energy.

[0010] Furthermore, in the above step 1), the thickness of the CrSBr material is 20-100 nm, and the thickness of the graphite material is within 10 nm.

[0011] Furthermore, in the above step 2), the specific voltage is 2.7V, the incident photon energy is 1.3-1.9eV, and the incident photon power is 0-20μW.

[0012] Furthermore, in the above step 3), a polarizing plate and a 1 / 2 wave plate are added to the excitation light path to change the polarization angle of the incident light.

[0013] Furthermore, in the above step 3), a quarter wave plate is used to change the optical rotation characteristics of the incident light to obtain the photocurrent difference under the excitation of left-handed and right-handed photons.

[0014] Furthermore, in the above step 4), the external magnetic field is from 0 to 3 T, and the photon energy is from 1.30 eV to 1.45 eV. The magnetic field is along the a-axis or b-axis of the CrSBr material spin jump, or along the c-axis of the CrSBr material spin tilt.

[0015] Furthermore, an electric meter with an accuracy within pA is used to measure the tunnel junction device.

[0016] Furthermore, an electrostatic shield is provided for the detection region of the tunnel junction device to avoid current changes introduced by environmental noise.

[0017] The technical advantages of the present invention are mainly reflected in the following points:

[0018] 1) The intrinsic van der Waals magnetic semiconductor CrSBr used in the present invention is an antiferromagnetic structure direct band gap semiconductor with a relatively high transition temperature (132K). Its unique spin-electron coupling effect makes it extremely sensitive to an external magnetic field. At the same time, CrSBr has strong optical absorption anisotropy. Compared with other semiconductor materials, the two-dimensional magnetic semiconductor CrSBr has an intrinsic magneto-optical coupling effect, which can realize multi-parameter photoelectric detection.

[0019] 2) The present invention utilizes the extremely stable and high polarization ratio anisotropy of the energy band structure of CrSBr to flexibly adjust the photocurrent response under a variety of external fields (magnetic field, light field and voltage) to achieve multi-parameter photoelectric detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is a schematic diagram of the tunnel junction device of the present invention.

[0021] Figure 2 Optical photograph of the tunnel junction device of the present invention is shown.

[0022] Figure 3 The photocurrent-photon energy spectrum of the tunnel junction in the specific embodiment of the present invention shown in the figure is obtained under a bias voltage of 2.7 V when the incident light is polarized along the b-axis and a-axis of CrSBr, and a linear dichroism ratio of nearly 60 is obtained under excitation of 1.376 eV incident photons.

[0023] Figure 4 The curve of the photocurrent-photon energy spectrum changing with the external magnetic field in the specific embodiment of the present invention is shown, and the photocurrent peak value and response degree adjustable by the external magnetic field are obtained.

[0024] Figure 5 The properties of the tunnel junction photocurrent evolving synchronously with the external magnetic field under 2.7V bias and 1.343eV incident photon excitation in a specific embodiment of the present invention are shown. DETAILED DESCRIPTION

[0025] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0026] This embodiment takes a 47nm CrSBr tunneling device as an example:

[0027] 1) Prepare the device. Figure 1 As shown in the figure, a two-dimensional layered graphite material (FLG) with a thickness of less than 10 nm and a CrSBr material with a thickness of 47 nm were obtained by mechanical exfoliation. The graphite material (bottom FLG), CrSBr material, and graphite material (top FLG) were placed on the Si / SiO2 electrode prefabricated by electron beam exposure and electron beam evaporation by dry transfer method. 2The tunnel junction device is finally prepared on the substrate, in which the overlap position of the upper and lower graphite materials of the CrSBr material is used as the detection junction area of ​​the photoelectric performance. The optical photo of the CrSBr tunnel junction device is shown in Figure 2 shown.

[0028] 2) Cool the tunnel junction device to 2K, apply a voltage of 2.7V to the tunnel junction device, change the incident photon energy and power based on a variable wavelength supercontinuum laser, obtain the photocurrent size and photoresponsivity that change with the incident photon energy under this voltage, and obtain an adjustable photocurrent.

[0029] 3) Change the polarization angle of the incident light, such as Figure 3 As shown, the photocurrent is distributed in an "8" figure with the polarization angle of the incident light. The excitation light is polarized along the lattice b-axis. The photocurrent has a response characteristic that can be adjusted with the external light field. The first main absorption peak is at 1.376eV, corresponding to the photocurrent enhancement caused by the absorption of excitons at the bottom of the conduction band and the top of the valence band. The second absorption peak appears at 1.745eV and above, corresponding to the photocurrent enhancement caused by the absorption of excitons at the bottom of the conduction band and the top of the second valence band; that is, the excitation light is polarized along the lattice b-axis, corresponding to the photocurrent maximum; the excitation light is polarized along the lattice a-axis, corresponding to the photocurrent minimum. The photocurrent-photon energy spectrum of the incident light polarized along the two extreme directions is divided to obtain the linear dichroism spectrum of the photocurrent. The linear dichroism comes from the ratio of the photocurrent along the a-axis and the b-axis, which can reach nearly 60 at 1.376eV energy and nearly 20 at high energy.

[0030] 4) Fix the incident photon polarization at an angle along the b-axis of the CrSBr material crystal, change the external magnetic field and photon energy, and detect the photocurrent response phase diagram of magnetic field-photon energy. Figure 4 , the photocurrent response to 1.376eV incident photons increased by about 6 times, and the photocurrent peak had a significant red shift, corresponding to the photocurrent's highly adjustable characteristics with the magnetic field. It is thus obtained that under different incident photon energies, the photocurrent will have different magnetic field responses, such as the photocurrent slowly increasing (such as when the incident photon is 1.343eV), the photocurrent first increasing, then decreasing, and then increasing again (such as when the incident photon is 1.350eV), etc. Figure 5 As shown, taking the excitation photons with energy of 1.343 eV as an example, the photocurrent change with the magnetic field is first measured. It can be seen that the photocurrent response changes synchronously and stably with the magnetic field. This can be used as a benchmark to detect disturbances in the ambient magnetic field.

[0031] Finally, it should be noted that the purpose of publishing the embodiments is to help further understand the present invention, but those skilled in the art can understand that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the contents disclosed in the embodiments, and the scope of protection claimed by the present invention shall be subject to the scope defined in the claims.

Claims

1. A multi-parameter photoelectric detection method based on a CrSBr material tunneling structure, the specific steps comprising: 1) placing graphite material, CrSBr material, and graphite material on a Si / SiO2 substrate with a prefabricated electrode in sequence by a dry transfer method to obtain a tunnel junction device; 2) Cooling the tunnel junction device to 2K, applying a specific voltage to the tunnel junction device, changing the incident photon energy and power based on a variable wavelength supercontinuum laser, obtaining the photocurrent size and photoresponsivity that vary with the incident photon energy under the voltage, and obtaining the photocurrent-photon energy spectrum; 3) changing the polarization angle of the incident light, measuring the "8" figure distribution of the photocurrent in step 2 along the polarization angle of the incident light, with the maximum along the b-axis of the CrSBr material lattice and the minimum along the a-axis of the CrSBr material lattice, and dividing the photocurrent-photon energy spectrum of the incident light polarized along the two extreme value directions to obtain the linear dichroism spectrum of the photocurrent; 4) Fix the polarization of the incident photon at an angle along the b-axis of the CrSBr material crystal, change the external magnetic field and photon energy, and detect the photocurrent response phase diagram of the magnetic field-photon energy.

2. The multi-parameter photoelectric detection method based on the CrSBr material tunneling structure according to claim 1, characterized in that: In the above step 1), the thickness of the CrSBr material is in the range of 20-100 nm, and the thickness of the graphite material is within 10 nm.

3. The multi-parameter photoelectric detection method based on the CrSBr material tunneling structure according to claim 1, characterized in that: In the above step 2), the specific voltage is 2.7V, the incident photon energy is 1.3-1.9eV, and the incident photon power is 0-20μW.

4. The multi-parameter photoelectric detection method based on the CrSBr material tunneling structure according to claim 1, characterized in that: In the above step 3), a polarizing plate and a 1 / 2 wave plate are added to the excitation light path to change the polarization angle of the incident light.

5. The multi-parameter photoelectric detection method based on the CrSBr material tunneling structure according to claim 1, characterized in that: In the above step 3), a quarter wave plate is used to change the optical rotation characteristics of the incident light to obtain the photocurrent difference under the excitation of left-handed and right-handed photons.

6. The multi-parameter photoelectric detection method based on the CrSBr material tunneling structure according to claim 1, characterized in that: In the above step 4), the external magnetic field ranges from 0 to 3 T, and the photon energy ranges from 1.30 eV to 1.45 eV.

7. The multi-parameter photoelectric detection method based on the CrSBr material tunneling structure according to claim 6, characterized in that: The magnetic field jumps along the a-axis or b-axis of the CrSBr material's spin, or the magnetic field tilts along the c-axis of the CrSBr material's spin.

8. The multi-parameter photoelectric detection method based on the CrSBr material tunneling structure according to claim 1, characterized in that: The tunnel junction device is measured using an ammeter with an accuracy within pA.

9. The multi-parameter photoelectric detection method based on the CrSBr material tunneling structure according to claim 1, characterized in that: An electrostatic shield is provided for the detection area of ​​the tunnel junction device.

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