Short-wave visible polarization detector based on one-dimensional ga s nanobelt and preparation method thereof

Abstract

The application discloses a short-wave visible polarized photoelectric detector based on one-dimensional GaS nanobelt and a preparation method thereof, and belongs to the technical field of nanometer functional materials, photoelectric detection and aerospace technology. The polarized photoelectric detector comprises a substrate, symmetrical electrodes and one-dimensional GaS nanobelt. The one-dimensional GaS nanobelt is prepared by the following method: placing GaS powder as a growth source at the front end of a muffle furnace quartz tube, placing a SiO2 / Si substrate at the rear end, introducing Ar / H2 into a tube furnace, heating the growth source GaS powder at 830-850 DEG C for 7 minutes, and gathering a plurality of one-dimensional GaS nanobelt materials on the substrate. A one-dimensional GaS nanobelt material is obtained by precise pasting and separating with a PDMS film with double-sided adhesion. Based on the geometric structure of the one-dimensional nanobelt, GaS presents polarization anisotropy, and thus polarized photoelectric detection and polarized imaging are realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of nanofunctional materials, photoelectric detection and aerospace technology, and specifically relates to a short-wave visible polarized photoelectric detector based on one-dimensional GaS nanobelt and a preparation method thereof. BACKGROUND

[0002] A polarized photoelectric detector is an advanced light detection device that can not only measure the intensity and wavelength of light but also detect the polarization state of light. This detector can improve the quality of imaging and the ability to identify objects, so it has a wide application prospect in many high-tech fields. Since the Discovery spacecraft first conducted polarized imaging observation of the Earth in 1984, polarized imaging technology has become a hot topic in the field of photoelectric detection technology. Compared with non-polarized imaging detection, polarized imaging can extract the Stokes vector of the target image, thereby obtaining the polarization angle and polarization degree images of the target spectrum, and can clearly image in environments with thick clouds, haze, dust, etc., making it have obvious advantages in target detail observation, background noise suppression and observation distance improvement. Traditional polarized photoelectric detectors usually require complex optical path designs, such as using polarizing mirrors and lenses, or using polarization encoding systems to achieve sensitive detection of polarized light. However, such designs often result in large volume, high cost and complex structure, limiting their application range. Recently, scientists have found that low-dimensional nanomaterials have great potential in the field of polarized light electronic devices. The optical and electrical properties of these materials exhibit anisotropy in the plane, which means they can produce different responses to polarized light in different directions. Using these materials, it is possible to design smaller, cheaper and simpler polarized photoelectric detectors, thereby promoting the miniaturization and integration of polarized photoelectric systems. Gallium sulfide (GaS), a semiconductor material with an indirect band gap, has attracted attention in the field of ultraviolet-short wave visible photoelectric detection due to its ultra-wide band gap, good environmental resistance and suitable preparation cost. However, due to the in-plane symmetry of traditional gallium sulfide, its inherent structure does not have the ability to respond to polarized light. Therefore, it is urgent to find an effective strategy to expand the application range of GaS in the field of light detection, realize polarized light detection technology based on GaS structure, and then realize large-scale controllable production. The existing technology needs further improvement and innovation. SUMMARY

[0003] The purpose of the present application is to solve the problem of lack of polarized light influence characteristics caused by the in-plane symmetry of traditional GaS. The present application provides a one-dimensional GaS nanobelt material and a short-wave visible polarized detector based on one-dimensional GaS nanobelt and a preparation method thereof.

[0004] The one-dimensional GaS nanobelt material is prepared by the following method: GaS powder is placed in the front end of a muffle furnace quartz tube, a SiO2 / Si substrate is placed in the rear end, Ar / H2 is introduced into the tube furnace, the GaS powder is heated at 830-850 DEG C for 7 minutes, and a plurality of one-dimensional GaS nanobelt materials are gathered on the substrate; a PDMS film with double-sided adhesion is precisely adhered to separate a one-dimensional GaS nanobelt material.

[0005] The GaS powder is 12-14 cm away from the SiO2 / Si substrate.

[0006] The heating is first to raise the furnace temperature from room temperature 25 DEG C to 700 DEG C for 20 minutes, then to set the temperature to 840 DEG C for 16 minutes after the furnace is preheated, to move the center temperature zone of the muffle furnace to the position of the GaS powder when the temperature is raised to 820 DEG C, to adjust the Ar flow rate to 55 sccm, to raise the H2 flow rate to 35 sccm when the growth temperature 840 DEG C is reached, to adjust the Ar flow rate to 55 sccm, to raise the H2 flow rate to 35 sccm when the growth temperature 840 DEG C is reached, to successfully grow two-dimensional GaS nanobelt, to stop introducing H2, to raise the Ar flow rate to 80 sccm, to exhaust H2, and to remove the heating temperature zone from the growth source after cooling.

[0007] The SiO2 / Si substrate is sequentially ultrasonically cleaned with trichloroethylene, acetone, isopropyl alcohol, ethanol and deionized water, and is dried with nitrogen for standby; the ultrasonic power is 80 W, and the ultrasonic time is 10 min.

[0008] The one-dimensional GaS nanobelt short-wave visible polarized photodetector is provided with two electrodes and one-dimensional GaS nanobelt material on a SiO2 / Si substrate; the two electrodes are deposited on the two sides of the one-dimensional GaS nanobelt material by a vacuum thermal evaporation plating method.

[0009] The one-dimensional GaS nanobelt material is prepared by the method of claim 1.

[0010] The electrodes are gold electrodes, and the channel interval of the two electrodes is 5 mu m.

[0011] The preparation method of the one-dimensional GaS nanobelt short-wave visible polarized photodetector comprises the following steps:

[0012] S1: transferring the one-dimensional GaS nanobelt material: placing the SiO2 / Si substrate on a two-dimensional material transfer platform, precisely adhering a one-dimensional GaS nanobelt material of claim 1 to the SiO2 / Si substrate by a PDMS film with double-sided adhesion, transferring the one-dimensional GaS nanobelt material to the center position of the SiO2 / Si substrate, heating the platform, lifting the PDMS to lose adhesion, vacuum heating the SiO2 / Si substrate with the attached sample to 120 DEG C, annealing, and cooling to room temperature.

[0013] S2: making electrodes: spin coating photoresist on the SiO2 / Si substrate with one-dimensional GaS nanobelt material attached, drying at 120 DEG C; after alignment, fixed-point ultraviolet exposure, development and nitrogen blowing dry; vacuum evaporation plating, removing glue, preparing 2 symmetrical electrodes on both sides of the one-dimensional GaS nanobelt material;

[0014] S3: vacuum heating at 100 DEG C for 2h, cooling to room temperature, obtaining a short-wave visible polarization detector based on one-dimensional GaS nanobelt.

[0015] The application adopts the method of CVD growth of one-dimensional material to break the in-plane optical isotropy, successfully prepares a short-wave visible polarization photodetector based on one-dimensional GaS nanobelt based on the fixed-point ultraviolet lithography method and precise transfer technology, and realizes the polarization imaging of small size pixels. Under the irradiation of short-wave visible (405nm) laser, polarization detection can be carried out, the response speed is considerable, the responsivity is high, and clear small size pixel polarization imaging can be carried out. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a preparation flowchart of the short-wave visible polarization photodetector of one-dimensional GaS nanobelt of the application;

[0017] Figure 2 It is a design schematic diagram of the short-wave visible polarization photodetector of one-dimensional GaS nanobelt of the application;

[0018] Figure 3 It is an optical microscope diagram and AFM thickness schematic diagram of one-dimensional GaS nanobelt of the application;

[0019] Figure 4 It is a TEM transmission electron microscope diagram of one-dimensional GaS nanobelt of the application, (a) top view, (b) side view;

[0020] Figure 5 It is an atomic structure schematic diagram of one-dimensional GaS nanobelt of the application;

[0021] Figure 6 It is a polarization Raman spectrum diagram of one-dimensional GaS nanobelt of the application;

[0022] Figure 7 It is a photoelectric detection diagram of the short-wave visible polarization photodetector of one-dimensional GaS nanobelt of the application;

[0023] Figure 8 It is a polarization photoelectric detection diagram of the short-wave visible polarization photodetector of one-dimensional GaS nanobelt of the application;

[0024] Figure 9 It is a polarization photoelectric detection diagram of the short-wave visible polarization photodetector of one-dimensional GaS nanobelt of the application;

[0025] Figure 10 The photoluminescence spectrum of the one-dimensional GaS nanobelt of the present application;

[0026] Figure 11 The polarized imaging schematic diagram of the short-wave visible polarized photodetector of the one-dimensional GaS nanobelt of the present application;

[0027] Figure 12 The polarized imaging schematic diagram of the short-wave visible polarized photodetector of the one-dimensional GaS nanobelt of the present application. DETAILED DESCRIPTION

[0028] Example 1

[0029] The GaS nanobelt is grown based on the CVD chemical vapor deposition method, including the following steps:

[0030] Step 1: 7 mg of GaS powder is weighed and placed in the center of a quartz boat 1;

[0031] Step 2: Prepare the substrate:

[0032] The single-sided Si and 300 nm SiO2 N-type substrate of Hefei Keyikai Material Technology Co., Ltd. is used as the substrate material, and the wafer-level SiO2 / Si substrate is precisely cut by a fiber laser marking machine, the laser power is 90%, the cutting speed is 20 mm / s, the cutting frequency is 20 kHz, and the cutting is performed to 1 cm*1 cm size as the substrate;

[0033] Step 3: Place the clean substrate in a quartz boat 2, with the substrate SiO2 facing upwards; place the quartz boat 2 on the right side of the quartz boat 1, and push it into the muffle furnace quartz tube, so that the GaS powder is 13 cm away from the clean substrate, and Ar gas is introduced at a flow rate greater than 80 sccm to expel air;

[0034] Step 4: Set the temperature program: first, increase the furnace temperature from room temperature 25℃ to 700℃ for 20 minutes, and then set the temperature to increase to 840℃ for 16 minutes after the furnace is preheated, and move the center temperature zone of the muffle furnace to the position of the growth source GaS powder when the temperature is increased to 820℃, see the attached Figure 1 Red area;

[0035] Step 5: Adjust the Ar flow rate to 55 sccm; when the growth temperature 840℃ is reached, increase the H2 flow rate to 35 sccm;

[0036] Step 6: Wait for 7 minutes, and successfully grow two-dimensional multiple GaS nanobelts;

[0037] Step 7: Stop introducing H2, increase the Ar flow rate to 80 sccm, exhaust H2, move the heating temperature zone away from the growth source, and take out the grown substrate with multiple nanowires for standby.

[0038] Example 2

[0039] The preparation method of the short-wave visible polarized photodetector based on one-dimensional GaS nanobelt comprises the following steps:

[0040] Step 1: Make a clean substrate;

[0041] Step 2: Transfer the one-dimensional GaS nanosheet material, see the attached Figure 1 :

[0042] 1) Take the one-dimensional GaS nanosheet material prepared by CVD, with a thickness of about 100 nm and a large number;

[0043] 2) Place the substrate with multiple one-dimensional GaS nanosheet materials on the two-dimensional material transfer platform, and use a piece of 0.25 cm 2 The PDMS film with double-sided adhesion is pasted on the glass slide on one side, and the other side is precisely pasted on the nanosheet with excellent morphology by microscope assisted corner, and after compaction, the nanosheet is lifted to the PDMS, and during the process, the transfer platform is slightly inclined to ensure that only the required nanosheet is picked up on the PDMS;

[0044] 3) Place the clean substrate on the two-dimensional transfer platform, keep the platform horizontal, and accurately drop the PDMS with nanosheet on the SiO2 / Si substrate through the microscope, and after compaction, the platform is heated to 80℃ at a rate of 2℃ / min, and kept for ten minutes, and the PDMS is deactivated and lifted, and the nanosheet falls on the SiO2 / Si substrate;

[0045] 4) Vacuum anneal the substrate with the attached sample, that is, place the sample in a vacuum quartz tube, heat to 120℃ at a rate of 3℃ / min, and then anneal for 1h, and then cool to room temperature at a rate of 3℃ / min. See the attached Figure 3 , the width of the successfully transferred nanobelt is about 1 micron, the thickness is about 120 nm, and the length is greater than 50 microns;

[0046] Step 3: Make electrodes:

[0047] 1) Form a uniform layer of photoresist film on the SiO2 / Si substrate containing GaS nanosheet on the surface by two-step spin coating in yellow light environment, and use ultraviolet exposure photoetching method to construct the electrode as shown in Figure 2 (Photoresist AZ-5214, exposure energy 180 mJ / cm 2 );

[0048] 2) The process parameters of the two-step spin coating of photoresist are as follows: the first step is set to 600 rad / s, and the time is 6s; the second step is set to 4000 rad / s, and the time is 30s;

[0049] 3) Bake the spin-coated film at 120℃ for 90 seconds, then align the drawing with the nanowire sample and expose it to ultraviolet light;

[0050] 4) After 60s development, the position where the electrode needs to be prepared is exposed by exposure. A 50nm layer of Au is deposited by vacuum thermal evaporation coating. The photoresist is removed by cleaning with acetone. The resulting device is vacuum heated at 100°C for 2 hours and cooled to room temperature to obtain the polarization photodetector. The GaS position exposed between the two electrodes is the channel material.

[0051] In the detector of this invention, GaS nanoribbons are used as photoconductive materials to achieve photoelectric conversion. Two symmetrical electrodes are located at the two ends of the nanoribbon and are kept perpendicular. Photogenerated carriers generated by photoexcitation are transmitted to the two symmetrical electrodes. The two electrodes are connected to external source meters, and the generation of photocurrent can be observed, which can be further used for the detection of polarized light.

[0052] Example 3

[0053] Methods for constructing and testing the optical path of a polarization imaging system

[0054] 1) See Appendix Figure 12 The linearly polarized laser passes through a half-wave plate and then through a scattering medium (frosted glass is used in this invention) before illuminating a circular mask (1 cm in diameter). After passing through the mask, it illuminates a short-wave visible polarized photodetector based on a one-dimensional GaS nanoribbon.

[0055] 2) Using a two-dimensional moving platform, the mask template is moved at a speed of 0.5 mm / s to simulate a multi-array detection mode and to image the mask template.

[0056] 3) Rotating the half-wave plate changes the polarization direction of different incident light, which is equivalent to rotating the sample and is beneficial for achieving DOLP polarization imaging.

[0057] Performance Characterization of Short-Wavelength Visible Polarization Photodetectors Based on One-Dimensional GaS Nanoribbons

[0058] See Figure 4 , 5 As shown, the large-diameter atoms are Ga, and the small-diameter atoms are S. TEM and atomic structure models of GaS show that GaS is a layered semiconductor material, with each layer consisting of repeating Ga-SS-Ga units. The TEM top view shows a stable hexagonal structure in the z-direction, indicating good crystallinity and belonging to the hexagonal crystal system. Ga and S atoms within the GaS layers are connected by covalent bonds, while interlayer coupling is achieved through van der Waals forces. TEM images show that the cross-section of the CVD-prepared one-dimensional GaS nanoribbons exhibits an ABC stacking pattern, consistent with γ-phase arrangement. Figure 11The photoluminescence spectrum shows that the optical band gap of GaS is 2.53 eV, which makes the GaS layered material be used for manufacturing a short-wave visible photodetector; the indirect band gap GaS does not have good luminescence characteristics, and the photoluminescence peak is weak. However, the light absorption of GaS is good and has good photoconductivity. This photoconductivity is that the conductivity of the material under the irradiation of light at a certain wavelength is different from the conductivity in the dark state; because the photoconductive material can absorb energy to generate a large number of photo-generated carriers under the action of laser induction, thereby promoting the conduction effect and improving the conductivity of the material, GaS is a better photoconductive material as a group III transition metal monosulfide compound. The traditional two-dimensional GaS material has in-plane symmetry, and the intrinsic GaS structure does not have a polarized light response characteristic. Based on this, the embodiment of the application provides a short-wave visible polarized photodetector based on one-dimensional GaS nanobelt, so as to further expand the application of GaS in the field of light detection and realize polarized imaging based on GaS nanostructure. The prepared one-dimensional GaS nanobelt photodetector can use a source table and a probe to perform a series of basic photoelectric and polarized photoelectric tests on the Au evaporated at both ends.

[0059] In order to identify the selected material in the one-dimensional geometry structure, the in-plane optical isotropy is broken, and the optical anisotropy appears, the one-dimensional GaS nanobelt material is tested by angle-resolved polarized Raman spectrum: three vibration modes of GaS are detected: E 2g 1 ,A 1g 1 , and A 1g 2 corresponding to wave numbers 304 cm -1 , 188 cm -1 , 359 cm -1 , wherein the A 1g mode changes periodically with the angle change mode peak, and good optical anisotropy is shown, as shown in the accompanying Figure 6 .

[0060] The photoluminescence spectrum of the material is also collected by using a 320 nm laser, and the result is shown in the figure, and the luminescence peak is about 490 nm. The band gap can be used to infer that the measured material is a multilayer structure, and from the accompanying Figure 3 , it can be seen that the thickness of the material is about 120 nm (the thickness of a single layer of GaS material is less than 1 nm).

[0061] Under the irradiation of a 405 nm laser, the IV curve of the material is measured, as shown in the accompanying Figure 7It can be seen from the curve that the device is turned on, and the photocurrent is in the order of nanampere (nA). At a high voltage (5V), a strong photocurrent can be obviously observed, because the applied bias field accelerates the separation of electrons and holes, and the photocurrent increases with the increase of the excitation light power. The IT curve shows that the photocurrent is improved by an order of magnitude, and the light-dark current is obviously distinguished, and the response speed reaches the order of ms.

[0062] In order to explore the performance of the one-dimensional GaS nanosheet polarized photoelectric detector, the present application carries out the polarized light response test of the detector for various lasers in the visible band, wherein the polarized response under 405nm laser is the strongest, as shown in the accompanying Figure 8 After multiple tests, referring to the accompanying Figure 8 When 1.5V is selected as the bias voltage, a higher polarization ratio 1.25 can be achieved; when 5V is selected as the bias voltage, a lower dark current, a larger on-off ratio (~10 3 ) and a more excellent polarization ratio can be maintained.

[0063] Under the above conditions, the one-dimensional GaS nanosheet polarized photoelectric detector is applied by using the optical path built in example 2, and the polarized imaging under short-wave visible light is realized, and the effect diagram is as shown in the accompanying Figure 10 .

[0064] It should be noted that the application of the present application is not limited to the above examples. As a new photoelectric detector light guide material, GaS can capture the intensity and wavelength signals of light. Among them, artificial induction anisotropy, such as the introduction of metal antenna, stress induction introduction and the nanobelt processing used in the present application, can all improve the polarization detection performance index of the prepared device, that is, the anisotropy ratio. The present application is expected to realize large-scale controllable production and form an array type polarized imaging element.

Claims

1. A one-dimensional GaS nanobelt material, prepared by the following method: placing a growth source GaS powder at the front end of a muffle furnace quartz tube, placing a SiO2 / Si substrate at the rear end, introducing Ar / H2 into the tube furnace, heating the growth source GaS powder at 830-850℃ for 7 minutes, and gathering a plurality of one-dimensional GaS nanobelt materials on the substrate; precisely adhering and separating the one-dimensional GaS nanobelt material using a PDMS film with double-sided adhesion to obtain a one-dimensional GaS nanobelt material. First, the furnace temperature is increased from room temperature 25℃ to 700℃ for 20 minutes, and then the furnace is preheated for 16 minutes to 840℃. When the temperature reaches 820℃, the center temperature zone of the muffle furnace is moved to the position of the growth source GaS powder, and the Ar flow rate is adjusted to 55sccm. When the growth temperature of 840℃ is reached, the H2 flow rate is increased to 35sccm. When the growth temperature of 840℃ is reached, the H2 flow rate is increased to 35sccm. Successfully grow two-dimensional GaS nanobelt; stop introducing H2, increase Ar flow rate to 80sccm, exhaust H2, and move the heating zone away from the growth source. After cooling, take out.

2. The one-dimensional GaS nanoribbon material of claim 1, wherein: The distance between the GaS powder and the SiO2 / Si substrate is 12-14 cm. 3.The one-dimensional GaS nanoribbon material of claim 1 or 2, wherein: The SiO2 / Si substrate is sequentially ultrasonically cleaned with trichloroethylene, acetone, isopropyl alcohol, ethanol, and deionized water, and dried with nitrogen for standby use; the ultrasonic power is 80W, and the ultrasonic time is 10min.

4. A short-wave visible polarized photodetector of one-dimensional GaS nanobelt, characterized in that: On the SiO2 / Si substrate, two electrodes and a one-dimensional GaS nanobelt material are provided; the two electrodes are deposited on both sides of the one-dimensional GaS nanobelt material by vacuum thermal evaporation plating method. The one-dimensional GaS nanobelt material is prepared by the method of claim 1.

5. The short-wave visible polarized photodetector of one-dimensional GaS nanoribbons according to claim 4, characterized in that: The electrodes are gold electrodes, and the channel spacing of the two electrodes is 5μm. 6.A method for preparing a short-wave visible polarization detector based on a one-dimensional GaS nanobelt, comprising the following steps: S1: transferring a one-dimensional GaS nanobelt material: placing a SiO2 / Si substrate on a two-dimensional material transfer platform, precisely adhering a one-dimensional GaS nanobelt material of claim 1 using a PDMS film with double-sided adhesion; transferring to the center position of the SiO2 / Si substrate, heating the platform, and lifting the non-adhesive PDMS; vacuum heating the SiO2 / Si substrate with the attached sample to 120℃, annealing, and cooling to room temperature; S2: making electrodes: on the SiO2 / Si substrate with the attached one-dimensional GaS nanobelt material, spin-coating photoresist, drying at 120℃; aligning and exposing to ultraviolet light, developing, and drying with nitrogen; vacuum evaporation plating, removing the photoresist, and preparing 2 symmetric electrodes on both sides of the one-dimensional GaS nanobelt material; S3: vacuum heating at 100℃ for 2h, cooling to room temperature, and obtaining a short-wave visible polarization detector based on a one-dimensional GaS nanobelt.

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