CN110767769A - A detection unit, ultra-wideband optical detector and detection method - Google Patents

Abstract

This paper discloses a detection unit, an ultra-wideband photodetector and a detection method. The detection unit includes an NbS ₃ crystal sheet and two electrodes, and the two electrodes are respectively arranged at both ends of the NbS ₃ crystal sheet in the length direction, and Ohmic contacts were formed with the NbS ₃ crystal sheets, respectively. The ultra-wideband photodetector includes the above-mentioned detection unit, and a detection circuit for collecting potential difference data on the detection unit, and the two electrodes are respectively electrically connected to the detection circuit. The detection method mainly includes: fixing the detector, illuminating the detector and collecting the data of the detection circuit. This paper relates to a detection unit, an ultra-wideband photodetector and a detection method, which can overcome the problem of narrow detection bandwidth. advantage.

Description

A detection unit, ultra-wideband optical detector and detection method

technical field

The invention relates to the technical field of detection, in particular to a detection unit, an ultra-wideband optical detector and a detection method.

Background technique

The photodetector can convert the optical signal into an electrical signal, and then detect the optical power incident on its surface. Ultra-broadband photodetectors can simultaneously detect electromagnetic radiation in different wavelength bands, such as ultraviolet, visible light, infrared and even terahertz waves, and play a very important role in infrared imaging, remote sensing, environmental monitoring, astronomical detection, spectral analysis and many other fields. However, due to the limitation of photosensitive materials, the current photodetectors can only work in a specific wavelength band. The current ultra-broad spectrum detection is realized by integrating the detection methods of different wavelength bands and ensuring that all parts work synchronously. The biggest problem of this method is that the device structure is very complex and difficult to apply in practice. Therefore, ultra-broadband photodetection from terahertz to ultraviolet using a single device has become a current research hotspot.

Subject to the size of the band gap of the material itself, based on WSe ₂ (see Kim HS, Chauhan KR, Kim J, et al. Flexible vanadium oxide film for broadband transparent photodetector [J]. Applied Physics Letters, 2017, 110(10): 101907. ), Bi single crystal (see Yao JD, Shao JM, YangG W. Ultra-broadband and high-responsive photodetectors based on bismuth film at room temperature [J]. Scientific Reports, 2015, 5:12320.), MoS ₂ (see Xie Y, ZhangB, Wang S, et al. Ultrabroadband MoS ₂ Photodetector with Spectral Response from 445 to 2717nm[J]. Advanced Materials, 2017, 29(17):1605972.) and black phosphorus (see Xie Y, Zhang B, Wang S , et al.Ultrabroadband MoS ₂ Photodetector with Spectral Responsefrom 445 to 2717nm[J].Advanced Materials,2017,29(17):1605972.) Most of the detectors can only achieve broadband detection in the ultraviolet to infrared band, which is difficult to cover too far Hertz band. Graphene and topological insulators have Dirac cone band structures and are considered to be the darlings for realizing ultra-broadband photodetection. Unfortunately, for graphene, the light absorption of single-layer graphene is only 2.3%, which makes the responsivity of graphene detectors only a few mV/W (CN 107104167A). For topological insulators, only the surface has a Dirac cone structure, which also faces the problem of low absorption. In addition, the zero-bandgap structure makes the dark current of photodetectors based on graphene and topological insulators large, which seriously affects the signal-to-noise ratio of the device. Despite the presence of graphene heterojunctions (see Highly Sensitive, Gate-Tunable, Room-Temperature Mid-Infrared Photodetection Based on Graphene-Bi ₂ Se ₃ Heterostructure), topological insulator heterojunctions (see Yao, J.; Shao, J. ; Wang, Y.; Zhao, Z.; Yang, G. Ultra-broadband and highresponse of the Bi ₂ Te ₃ -Si heterojunction and its application as a photodetectorat room temperature in harsh working environments. Nanoscale 2015,7,12535-12541. ) and the graphene detector with three-dimensional microtubule structure (CN107394001A), however, it requires either additional bias voltage or relatively complicated fabrication process, which restricts the practical application of the device. In conclusion, ultra-broad spectrum detectors with detection bandwidths covering terahertz to ultraviolet need further research.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a detection unit, an ultra-wideband optical detector, and a detection method, which can overcome the problem of narrow detection bandwidth. Sensitive advantage.

In order to solve the above technical problems, this paper adopts the following technical solutions:

A detection unit for ultra-broadband light detection, comprising a NbS ₃ crystal sheet and two electrodes, the two electrodes are respectively arranged at both ends of the NbS ₃ crystal sheet in the length direction, and are respectively connected with the NbS ₃ crystal sheet. The sheets form ohmic contacts.

This article also provides an ultra-wideband photodetector, comprising the above-mentioned detection unit, and a detection circuit for collecting potential difference data on the detection unit, and the two electrodes are respectively electrically connected to the detection circuit.

A possible design includes a base for supporting the detection unit, and the detection unit is fixed on the base.

In a possible design, the two electrodes are set as two metal electrodes of the same material.

In a possible design, the two electrodes are set as two metal electrodes of different materials.

A possible design, the detection unit further includes a gate dielectric layer, a gate electrode and an antenna, the two electrodes are set as source electrodes and drain electrodes, and the gate dielectric layer is laid on the NbS ₃ crystal sheet and the two electrodes. On the upper surface of the heterojunction formed by the electrodes, the gate electrode is disposed on the upper end of the gate dielectric layer and in the center of the NbS ₃ crystal plate, and the antenna is connected to the source electrode and the gate electrode respectively.

In a possible design, the antenna includes a separate first antenna and a second antenna, the first antenna is connected to the source electrode, and the second antenna is connected to the gate electrode.

In a possible design, the material of the gate dielectric layer includes SiO ₂ , Al ₂ O ₃ , HfO ₂ or hexagonal boron nitride.

In a possible design, the antenna is configured as a helical antenna, a butterfly antenna or a log-periodic antenna.

In a possible design, both electrodes are in the form of sheets and both are fixed on the upper surface of the substrate or the upper surface of the NbS ₃ crystal sheet.

In one possible design, the substrate is flake-like and the material includes sapphire, Si/SiO ₂ , quartz, glass or mica.

In a possible design, there are multiple detection units, and the multiple detection units are arranged in a linear array or an area array.

In one possible design, the detection circuit is an electrical measuring device for reading the potential difference.

A possible design, a plurality of the detection units are arranged on a substrate and arranged in a linear array, the substrate includes a first substrate and a second substrate arranged at intervals, and the two electrodes of any one of the detection units are respectively fixed On the first substrate and the second substrate and at both ends of the NbS ₃ crystal sheet, ohmic contacts are formed with two of the electrodes respectively.

A possible design, there are multiple substrates, the substrates are arranged on the same plane, the substrates correspond to the detection units one-to-one, and the two electrodes of each detection unit penetrate the corresponding substrates , the NbS ₃ crystal plate of the detection unit is arranged on one side of the substrate and the two ends form ohmic contact with the two electrodes.

In a possible design, the cross section of the electrode is rectangular, and the electrode forms pins on the side of the substrate facing away from the NbS ₃ crystal sheet.

This paper also provides a detection method for the above-mentioned ultra-broadband light detector, including:

Fix the detector, and fix the detector on the optical translation stage;

Irradiate the detector, and control the light source to illuminate the detector, so that the light spot generated by the light source falls on the NbS ₃ crystal sheet;

Collect the detection circuit data, read and record the potential difference change data at both ends of the detection unit.

Beneficial effects of the embodiments of the present invention:

When the detector of the embodiment of the present invention is irradiated by a light source, the detection unit containing NbS ₃ crystal will generate a temperature gradient, and then a potential difference proportional to the light intensity will be generated at both ends of the detection unit. At the same time, this potential difference is amplified and read out through the detection circuit Ultra-broadband light detection can be realized.

The detection bandwidth of the detector of the embodiment of the present invention can cover from ultraviolet to terahertz band, has an ultra-wide detection bandwidth, and also has the advantages of high speed and sensitivity.

The detector of the embodiment of the present invention is simple to manufacture, low in cost, and has broad prospects in practical application.

Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the description, claims and drawings.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings:

Fig. 1 is the schematic diagram of the detector of the first embodiment;

Fig. 2 is the connection diagram of the detector of the first embodiment;

3 is a schematic diagram of the detector of the second embodiment;

4 is a schematic diagram of the detector of the third embodiment;

5 is a schematic diagram of a detection unit of Embodiment 3;

Fig. 6 is the connection diagram of the detector of the third embodiment;

7 is a schematic diagram of the detector of the fourth embodiment;

FIG. 8 is a schematic diagram of the detector of the fifth embodiment.

Reference symbols: 1-NbS ₃ crystal plate, 2-source electrode, 3-drain electrode, 4-substrate, 4-1-first substrate, 4-2-second substrate, 5-gate dielectric layer, 6-gate Electrode, 7-first antenna, 8-second antenna, 9-metal wire, 10-light, 11-detection circuit.

Detailed ways

In order to make the invention purpose, technical solutions and beneficial effects of the present application clearer, the embodiments of the present application will be described below with reference to the accompanying drawings. The features in can be arbitrarily combined with each other.

Please refer to FIG. 1 and FIG. 2 of the ultra-wideband photodetector according to the first embodiment of the present invention. As shown in FIG. 1 and FIG. 2 , the detector includes a detection unit and a detection circuit 11 for collecting data of the detection unit, wherein the detection unit further includes an NbS ₃ crystal plate 1 and electrodes, and the two electrodes are respectively arranged on the NbS ₃ Both ends of the crystal piece 1 in the length direction form ohmic contact therewith, and at the same time, the two electrodes are electrically connected to the detection circuit 11 respectively. Thus, the detector can convert the light irradiated on it into electrical signals, which can be read out by the detection circuit 11 to realize ultra-broadband light detection.

First, the NbS ₃ crystal sheet 1 is composed of NbS ₃ crystals in the shape of a long sheet. _NbS3 is a typical quasi-one-dimensional semiconductor material with rich physical properties such as Peierls phase transition and charge density waves. In recent years, low-dimensional materials with unique physical properties have gradually become a research hotspot, which also opens up the research field of new ultra-broadband detection methods. At present, researches on terahertz detection based on low-dimensional materials mostly focus on two-dimensional materials such as graphene and black phosphorus. In addition to these materials, there are many quasi-one-dimensional materials to be explored, such as the aforementioned NbS ₃ . However, the current research on NbS ₃ mostly focuses on the crystal structure, energy band structure and charge density wave phase transition characteristics, and little research on photodetection methods or even terahertz detection methods.

As shown in FIG. 1 and FIG. 2, the two electrodes are two metal electrodes of the same material, which are respectively provided with a source electrode 2 and a drain electrode 3, wherein the source electrode 2 and the drain electrode 3 are both sheet-like and are respectively provided On the upper surface of the NbS ₃ crystal piece 1, and form a good ohmic contact with the NbS ₃ crystal piece 1. Thus, the above-mentioned NbS ₃ crystal sheet 1 and the two electrodes are fixed to form a "NbS ₃ -metal" heterojunction. At the same time, the source electrode 2 and the drain electrode 3 are respectively electrically connected to the detection circuit 11 through lead wires (not shown in the figure) to form a loop, so as to transmit the electrical signal generated by the NbS ₃ crystal plate 1 to the detection circuit 11 for its measurement .

In addition, the detector also includes a substrate 4 for supporting the detection unit. The substrate 4 is in the shape of a thin sheet. The above-mentioned NbS ₃ crystal sheet 1 is fixed on the upper end face of the substrate 4. The substrate 4 can provide stable mechanical support for the detector. Including but not limited to sapphire, Si/SiO ₂ , quartz, glass or mica, this embodiment is made of sapphire.

Therefore, it can be seen that the detector is simple to manufacture and relatively low cost. And its detection method is also simple and quick. Specifically, the detection method mainly includes: fixing the detector, illuminating the detector, and collecting the data of the detection circuit 11 . Among them, when detecting, firstly, the base of the detector needs to be fixed on a stable and reliable optical translation stage, so that it can face the light directly. Secondly, turn on the light source, so that its light 10 can be focused on the "NbS ₃ -metal" heterojunction through the optical path, that is, the light spot falls on the NbS ₃ crystal plate 1, and the diameter value of the light spot should be smaller than that of the NbS ₃ crystal plate 1. The length of the light spot is usually 1-2mm in the laboratory, so that the light spot can only fall on one part of the NbS ₃ crystal sheet 1, and cannot cover the entire NbS ₃ crystal sheet 1. At this time, under the illumination, the temperature of the NbS ₃ crystal material increases, resulting in a photothermoelectric effect, which generates a significant current within a few milliseconds. The current intensity depends on the power of the electromagnetic wave. With the increase of the power of the electromagnetic wave, The photocurrent in the loop increases linearly with it; it can also be understood that light irradiation will cause a temperature difference between the two ends of the detection unit, and this temperature difference will generate a potential difference between its two ends proportional to the light intensity. Finally, the above-mentioned potential difference can be amplified and read out through the detection circuit 11, so that ultra-wideband light detection can be realized. Therefore, it can be seen that the detection response is less than 10 milliseconds, the response is fast, and the response is sensitive.

Please refer to FIG. 3 of the ultra-wideband photodetector according to the second embodiment of the present invention. The detector includes a detection unit and a detection circuit for collecting data of the detection unit, wherein the detection unit further includes a NbS ₃ crystal plate 1 and electrodes. Compared with the detector of the first embodiment, the two electrodes in this embodiment are two The metal electrodes of different materials, namely the source electrode 2 and the drain electrode 3 are of different materials, so that the detection unit constitutes two different "NbS ₃ -metal" heterojunctions. In addition, a coupling antenna can also be used at the above-mentioned electrodes to improve absorption.

Therefore, during the detection process of the detector, the size of the selected light spot should be much larger than the length of the NbS ₃ crystal sheet 1, so that the light irradiates the entire detection unit. Since the metal electrodes at both ends of the detection unit are of different materials, the two There is a difference in the Fermi levels at the ends, resulting in different Seebeck coefficients at the ends. The photothermoelectric effect is produced under illumination, which can generate a significant current within a few milliseconds. The current strength depends on the power of the electromagnetic wave. As the power of the electromagnetic wave increases, the photocurrent in the loop increases linearly, and the same The data can be read out through the detection circuit to realize ultra-wideband optical detection.

Please refer to FIG. 4 to FIG. 6 of the ultra-wideband photodetector according to the third embodiment of the present invention. Compared with the detector of the first embodiment, the detection unit further includes a gate dielectric layer 5 , a gate electrode 6 and an antenna, and the two electrodes are set as the source electrode 2 and the drain electrode 3 .

Specifically, the above-mentioned gate dielectric layer 5 is laid on the upper surface of the heterojunction formed by the NbS ₃ crystal sheet 1 and the two electrodes, and the gate dielectric layer 5 includes but is not limited to SiO ₂ , Al ₂ O ₃ , HfO ₂ or hexagonal nitrogen Boronide, the gate dielectric layer 5 of this embodiment adopts SiO ₂ . As far as the gate electrode 6 is concerned, it is also in the form of a flake, which is deposited on the upper end of the gate dielectric layer 5 and located in the center of the NbS ₃ crystal plate 1 , and the gate electrode 6 can gate control the detection unit through the gate dielectric layer. In addition, both the source electrode 2 and the gate electrode 6 are provided with antennas, and the antennas further include a first antenna 7 arranged on the source electrode 2 and a second antenna 8 arranged on the gate electrode 6. The first antenna 7 and the second antenna 8 are all metal parts, and the two form a butterfly antenna, which can be coupled under power-on conditions. The antenna is not limited to a butterfly antenna, but can also be a helical antenna or a log-periodic antenna. At the same time, the drain electrode 3 is connected to the detection circuit 11 through the metal wire 9, and the source electrode 2 is also connected to the detection circuit 11 to form a loop.

During the detection process of the detector, the size of the selected light spot is also much larger than the length of the NbS ₃ crystal sheet 1, so that the light irradiates the entire detection unit. Under the illumination condition, due to the antenna coupling, the source electrode 2 and the gate electrode 6 The channel material in between (i.e. NbS ₃ crystal) absorbs more energy and the temperature will be higher than the material temperature between the gate electrode 6 and the drain electrode 3, resulting in a photothermoelectric effect, which produces a significant amount of energy within a few milliseconds. The current intensity depends on the power of the electromagnetic wave. With the increase of the power of the electromagnetic wave, the photocurrent in the loop increases linearly, and the detection circuit 11 can read the data to realize ultra-wideband optical detection.

Please refer to the ultra-wideband light detector of the fourth embodiment of the present invention in FIG. 7 . Compared with the detector of the first embodiment, the substrate 4 is provided with a plurality of detection units, and the plurality of detection units are arranged in a linear array. Arranged in an array.

Specifically, the substrate 4 includes a first substrate 4-1 and a second substrate 4-2 arranged at intervals, the first substrate 4-1 and the second substrate 4-2 are arranged in parallel, and the two electrodes of any detection unit are respectively fixed on the On the first substrate and the second substrate, as shown in FIG. 7 , the drain electrode 3 is provided on the side of the second substrate 4-2 facing away from the first substrate 4-1, and the source electrode 2 is provided on the side of the first substrate 4-1. The side facing the second substrate 4-2. Notably, the NbS ₃ crystal plate 1 is cylindrical, one end of which penetrates the second substrate 4-2 and forms a good ohmic contact with the drain electrode 3, and the other end is fixed on the first substrate 4-1 and forms with the source electrode 2 Good ohmic contact. Of course, the source electrode 2 and the drain electrode 3 may also be disposed on the first substrate 4-1 and the second substrate 4-2 facing or facing away, respectively. In addition, a plurality of detection circuits 11 (not shown in the figure) correspond to the detection units one by one, and read the potential difference generated by the corresponding detection units respectively.

Therefore, when the same or different light rays illuminate multiple detection units at the same time, by reading the data of each detection unit, multiple ultra-broadband light detection processes can be performed simultaneously.

Referring to FIG. 8 , the ultra-wideband photodetector of the fifth embodiment of the present invention, compared with the detector of the first embodiment, includes a plurality of the detection units and the substrates 4 , and the plurality of substrates 4 and the detection units correspond one-to-one, forming a surface array arrangement.

Specifically, a plurality of identical substrates 4 are arranged on the same plane, an NbS ₃ crystal piece 1 is arranged between the source electrode 2 and the drain electrode 3 , and the NbS ₃ crystal piece 1 is located on one side of the substrate 4 and is respectively connected with the source electrode 2 A good ohmic contact is formed with the drain electrode 3 . In addition, the cross-sections of the source electrode 2 and the drain electrode 3 are both rectangular, and both penetrate the substrate 4 and extend downward to form pins, and the two pins can be inserted into the interface of the detection circuit 11 (not shown in the figure), Wire connections are omitted. The plurality of detection circuits 11 (not shown in the figure) correspond to the detection units one by one, and respectively read the data of the corresponding detection units.

Therefore, when the same or different light rays illuminate multiple detection units at the same time, by reading the data of each detection unit, multiple ultra-broadband light detection processes can be performed simultaneously.

Combining the above embodiments, it can be seen that the detection bandwidth of the detector can cover from ultraviolet to terahertz band, has an ultra-wide detection bandwidth, and also has the advantages of high-speed sensitivity and fast response. At the same time, the detector is simple in fabrication and low in cost, and has broad prospects in practical applications. In addition, although the detector in the above-mentioned embodiment realizes the detection through the photo-pyroelectric effect, those skilled in the art should understand that in other embodiments, the detector may also adopt, but not limited to, the radiant heat effect, the pyroelectric effect, etc. Other detection principles.

In the description of this application, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense, for example, "connected" may be a fixed connection, a detachable connection, or an integral Connection; either directly or indirectly through an intermediary. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiment", etc. means that a particular feature, structure, material or characteristic described in connection with the embodiment or example is included in this application at least one embodiment or example of . In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments disclosed in the present invention are as above, the described contents are only the embodiments adopted to facilitate the understanding of the present invention, and are not intended to limit the present invention. Any person skilled in the art to which the present invention belongs, without departing from the spirit and scope disclosed by the present invention, can make any modifications and changes in the form and details of the implementation, but the scope of the patent protection of the present invention still needs to be The scope defined by the appended claims shall prevail.

Claims (17)

1. a detection unit, for ultra-wideband light detection, is characterized in that, comprises NbS ₃ crystal plate and two electrodes, two described electrodes are respectively arranged at the length direction two ends of described NbS ₃ crystal plate, and respectively. An ohmic contact is formed with the _NbS3 crystal sheet. 2. An ultra-wideband photodetector, characterized in that it comprises a detection unit as claimed in claim 1, and a detection circuit for collecting potential difference data on the detection unit, wherein the two electrodes are respectively connected to the detection unit. circuit electrical connection. 3. The ultra-wideband light detector according to claim 2, characterized in that it comprises a base for supporting the detection unit, and the detection unit is fixed on the base. 4 . The ultra-wideband photodetector according to claim 3 , wherein the two electrodes are set as two metal electrodes of the same material. 5 . 5 . The ultra-wideband photodetector according to claim 3 , wherein the two electrodes are set as two metal electrodes of different materials. 6 . 6. The ultra-wideband photodetector according to claim 3, wherein the detection unit further comprises a gate dielectric layer, a gate electrode and an antenna, and the two electrodes are set as a source electrode and a drain electrode, and the gate electrode is set as a source electrode and a drain electrode. A dielectric layer is laid on the upper surface of the heterojunction formed by the NbS ₃ crystal plate and the two electrodes, the gate electrode is arranged on the upper end of the gate dielectric layer and is located in the center of the NbS ₃ crystal plate, and the antenna are connected to the source electrode and the gate electrode, respectively. 7. The ultra-wideband photodetector according to claim 6, wherein the antenna comprises a separate first antenna and a second antenna, the first antenna is connected to the source electrode, and the second antenna is connected to the source electrode. An antenna is connected to the grid electrode. 8 . The ultra-wideband photodetector according to claim 6 , wherein the material of the gate dielectric layer comprises SiO ₂ , Al ₂ O ₃ , HfO ₂ or hexagonal boron nitride. 9 . 9 . The ultra-wideband light detector according to claim 6 , wherein the antenna is configured as a helical antenna, a butterfly antenna or a logarithmic periodic antenna. 10 . 10. The ultra-wideband photodetector according to claim 4, 5 or 6, characterized in that, both electrodes are in the form of sheets and both are fixed on the upper surface of the substrate or the upper surface of the NbS ₃ crystal plate . 11. The ultra-wideband photodetector according to any one of claims 3-9, wherein the substrate is flake-shaped, and the material comprises sapphire, Si/ _SiO2 , quartz, glass or mica. 12. The ultra-wideband photodetector according to any one of claims 3-9, wherein there are multiple detection units, and the multiple detection units are arranged in a linear array or an area array. 13. The ultra-wideband photodetector according to any one of claims 2-9, wherein the detection circuit is an electrical measuring device for reading the potential difference. 14. The ultra-wideband photodetector according to claim 12, wherein a plurality of the detection units are arranged on a substrate and are arranged in a linear array, and the substrate comprises a first substrate and a second substrate arranged at intervals , the two electrodes of any of the detection units are respectively fixed on the first substrate and the second substrate, and the two ends of the NbS ₃ crystal plate respectively form ohmic contact with the two electrodes. 15. The ultra-wideband photodetector according to claim 12, characterized in that, there are a plurality of the substrates, the plurality of the substrates are arranged on the same plane, the substrates and the detection units are in one-to-one correspondence, and each The two electrodes of the detection unit penetrate through the corresponding substrate, the NbS ₃ crystal plate of the detection unit is arranged on one side of the substrate, and two ends of the detection unit form ohmic contact with the two electrodes. 16 . The ultra-wideband photodetector according to claim 15 , wherein the cross-section of the electrodes is rectangular, and the electrodes form pins on the side of the substrate facing away from the NbS ₃ crystal sheet. 17 . 17. A detection method for an ultra-wideband photodetector as claimed in claims 2-16, characterized in that, comprising: Fix the detector, and fix the detector on the optical translation stage; Irradiate the detector, and control the light source to illuminate the detector, so that the light spot generated by the light source falls on the NbS ₃ crystal sheet; Collect the detection circuit data, read and record the potential difference change data at both ends of the detection unit.

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