Single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and preparation method and application thereof

Abstract

The invention discloses a single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and a preparation method thereof, comprising the following steps: preparing a copper (111) film on a sapphire (0001) substrate by a direct current magnetron sputtering method; coating the prepared copper (111) film in an envelope manner, and preparing a single crystal graphene / copper (111) film by a chemical vapor deposition method; placing the prepared single crystal graphene / copper (111) substrate in a ferric chloride solution for etching to roughen the single crystal graphene / copper (111) substrate; placing the etched single crystal graphene / copper (111) substrate, a tellurium source and a molecular sieve in different temperature zones of a high temperature tube furnace, respectively, and heating the tube furnace to allow the tellurium source volatilized to the substrate surface to react with the copper (111) below the graphene to grow to obtain a single crystal graphene / two-dimensional cuprous telluride heterojunction. The preparation method of the present invention can be mass-produced and does not require transfer. The heterojunction SERS substrate significantly enhances the signal of the detected probe molecule and has high reproducibility.

Description

Technical Field

[0001] The present invention relates to the technical field of two-dimensional nanomaterial preparation and surface enhanced Raman spectroscopy (SERS) detection, and in particular to a single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and a preparation method thereof. Background Art

[0002] As the study of graphene has become popular all over the world, the exploration of graphene / two-dimensional material heterojunctions has gradually become a hot topic in the field of physics and materials science in recent years. In terms of material preparation, previous methods usually use micromechanical exfoliation and transfer technology to stack graphene and two-dimensional materials into heterostructures. However, these technologies are not realistic for low-cost large-scale production of heterojunction materials. Chemical vapor deposition is a large-scale growth method for two-dimensional materials such as single-crystalline graphene and molybdenum disulfide. However, due to the poor compatibility of two-dimensional materials such as molybdenum disulfide with graphene growth conditions, the direct growth of single-crystalline graphene / two-dimensional material heterojunctions has become a challenge in this field. Therefore, we propose a method for preparing large-scale, high-quality single-crystalline graphene / two-dimensional cuprous telluride heterostructures without transfer.

[0003] Surface enhanced Raman spectroscopy (SERS) is a type of in-situ rapid and non-destructive spectroscopy technology that can provide fingerprint structural information of substances, has extremely high surface detection sensitivity and accuracy, and can achieve single-molecule level detection. It has broad application prospects in biomedicine, trace analysis, food safety and other fields. Precious metal nanoparticles such as gold, silver, copper, etc. are widely used in the field of surface enhanced Raman spectroscopy due to their excellent performance and high enhancement factor. However, their stability and repeatability are difficult to guarantee, and the high preparation cost inhibits their development. Two-dimensional semiconductor materials have become popular materials for research in the field of surface enhanced Raman (SERS) due to their controllable valence band, atomic-level flatness, and excellent optoelectronic properties. Graphene is a two-dimensional carbon nanomaterial with atomic layer thickness, large specific surface area and superior molecular adsorption capacity, which can improve and enhance the Raman signal of probe molecules. Nanocrystals of copper telluride show strong near-infrared optical absorption associated with localized surface plasmon resonance. Surface enhanced Raman scattering sensors for unconventional optical probes are designed using this plasmon resonance. Summary of the invention

[0004] In view of the above problems existing in the preparation of two-dimensional heterojunction and its SERS application field, the present invention provides a method for preparing large-scale, high-quality single-crystalline graphene / two-dimensional cuprous telluride heterostructure without transfer, and demonstrates its application in the SERS field.

[0005] The technical solution to realize the present invention is: a single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and a preparation method thereof, the steps are as follows:

[0006] (1) Copper (111) thin films were prepared on sapphire (0001) substrates by direct current magnetron sputtering.

[0007] (2) Preparing single-crystalline graphene by chemical vapor deposition after envelope coating on the copper (111) film obtained in step (1).

[0008] (3) The single crystal graphene / copper (111) substrate prepared in (2) is placed in a 0.5 mol / L ferric chloride solution for etching, so that the prepared single crystal graphene / copper (111) substrate can be roughened.

[0009] (4) The single crystal graphene / copper (111) substrate, tellurium source and molecular sieve etched in (3) are placed in different temperature zones of a high temperature tube furnace respectively. Under certain pressure and carrier gas conditions, the tube furnaces in different temperature zones are heated to different temperatures and kept warm for a certain period of time, so that the tellurium source volatilized to the surface of the substrate reacts with the copper (111) film under the graphene to grow a single crystal graphene / two-dimensional cuprous telluride heterojunction.

[0010] Furthermore, in the step (1), the copper (111) film is deposited by a DC magnetron sputtering method, the sputtering time is 28-40 minutes, the sputtering temperature is 150-200°C, the sputtering pressure is 0.4-1.2 Pa, the gas flow rate is 20 sccm, the sputtering power is 100 W, and the sputtered copper (111) film thickness is 500 nm-1500 nm.

[0011] Furthermore, in step (2), the pressure is low pressure 18-200 Pa, the carrier gas is an inert gas or nitrogen, the carrier gas flow rate is 10-1000 sccm, the temperature is raised to 980-1030°C, the heating time is 10-55 min, the heat preservation time is 20-50 min, and then 0.5-5 sccm of methane is introduced and kept warm for 20-60 min.

[0012] Furthermore, the roughness of the substrate obtained after etching in step (3) is 2-80 nm.

[0013] Furthermore, in step (4), the tellurium source and the molecular sieve are placed in the first temperature zone, and the single crystal graphene / copper (111) substrate is placed in the third temperature zone, and a heat insulation board is used in the middle to form a temperature difference between the two temperature zones.

[0014] Furthermore, in step (4), the first temperature zone where the tellurium source and the molecular sieve are located is heated to 450-600°C and maintained, and the third temperature zone where the single crystal graphene / copper (111) substrate is located is heated to 150-300°C and maintained. The pressure is low pressure or normal pressure, the carrier gas is an inert gas or nitrogen, the carrier gas flow rate is 10sccm-1000sccm, the tellurium source amount is 50-4000mg, the molecular sieve amount is 30-2000mg, the heating time is 10-30min, and the holding time is 20min-4h. The low pressure is 12-100Pa, and the carrier gas flow rate is 10-500sccm.

[0015] The application of the single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate in the present invention in SERS: the single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate is detected by using a probe molecule to obtain a signal of the probe molecule with enhanced signal, and the detection limit can reach 10 11 .

[0016] Furthermore, the probe molecule is Nile red or methylene blue.

[0017] The beneficial effects of the present invention are as follows: the present invention creatively uses chemical vapor deposition to grow a two-dimensional heterogeneous interface in situ, and the prepared heterogeneous interface is clean, avoiding the influence of defects on the sample caused by the traditional graphene transfer process and the influence of pollutants on the enhancement effect of surface enhanced Raman. The preparation process is simple and novel, and a layer of single crystal graphene is covered on cuprous telluride to effectively prevent the oxidation of cuprous telluride, and a strong SERS effect can be obtained. At the same time, by controlling the thickness of the magnetron sputtered copper film, a single crystal graphene / two-dimensional cuprous telluride heterojunction of different thicknesses can be obtained. The sample is determined to be a high-quality, large-area single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate material by optical microscopy, Raman spectroscopy, scanning electron microscopy, atomic force microscopy and other analytical methods.

[0018] As a semi-metallic material, graphene is widely used in SERS substrates. Combining it with cuprous telluride to prepare SERS substrates can achieve high SERS activity with good reproducibility, which is comparable to precious metal SERS substrates. It is expected to be widely used in food hygiene, environmental testing, national defense security, and medical diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly described below. Of course, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1Schematic diagram of the growth of a single-crystal graphene / two-dimensional cuprous telluride heterojunction prepared in Example 1 of the present invention.

[0021] Figure 2 This is a typical optical photograph of a single-crystal graphene / two-dimensional cuprous telluride heterojunction prepared under low pressure in Example 1 of the present invention, in which uniformly distributed hexagonal samples can be seen.

[0022] Figure 3 The scanning electron microscope test results of the sample prepared by low pressure in Example 1 of the present invention are: a. The sample prepared under the conditions of Example 1, the single crystal graphene / two-dimensional cuprous telluride heterojunction covers the entire substrate; b. The sample prepared under the same conditions with a graphene growth time of 15 minutes, and a regular hexagonal sample can be seen; c. The cross-sectional view of the single crystal graphene / two-dimensional cuprous telluride heterojunction.

[0023] Figure 4 The Raman test results of the single-crystalline graphene / two-dimensional cuprous telluride heterojunction prepared in Example 1 of the present invention: there are no other characteristic peaks in the figure except the characteristic peak of the sample, which shows that the crystallinity of the sample is good.

[0024] Figure 5 a is the atomic force microscopy test result of the single crystal graphene / two-dimensional cuprous telluride heterojunction prepared in Example 1 of the present invention, and it can be seen that the surface is relatively flat. Figure 5 b is the atomic force microscopy test result of the prepared single-crystal graphene / two-dimensional cuprous telluride heterojunction after etching, and it can be seen that the surface has been roughened.

[0025] Figure 6 The Raman detection results of the single crystal graphene / two-dimensional cuprous telluride heterojunction prepared in Example 1 of the present invention for SERS detection: a. The peak position of the SERS enhancement signal of the single crystal graphene / two-dimensional cuprous telluride heterojunction prepared by the method of the present invention. b. The Raman peak of the pure Nile red solution at the same concentration, which shows that the prepared single crystal graphene / two-dimensional cuprous telluride heterojunction does have a SERS effect. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] A single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and a preparation method thereof, the steps are as follows:

[0029] Step 1: Cut the sapphire substrate into 1×1 cm size and put it into the piranha solution. Heat the piranha solution on a heating table at 90°C for 1 h. Then take out the sapphire, rinse it repeatedly with deionized water for 5 min, blow it dry with a nitrogen gun, put it into the magnetron sputtering chamber, and evacuate it to 5×10 -5 Pa, pre-sputtering was carried out first, and then sputtering was carried out. The sputtering conditions were: sputtering time 30 min, sputtering temperature 180 ° C, sputtering pressure 1 Pa, gas flow rate 20 sccm, sputtering power 100 W. Finally, when the sample cooled to room temperature, the sample was taken out from the magnetron sputtering chamber to obtain a copper (111) thin film with a thickness of 700 nm.

[0030] Step 2: Place the sputtered copper (111) film in the second temperature zone of the tube furnace, pump down the tube furnace to 2Pa, introduce 150sccm argon and 10sccm hydrogen to a pressure of 51Pa, heat the tube furnace to 1000°C for 50min and keep it for 30min, then introduce 2sccm methane and keep it for 20min, stop introducing methane after the reaction is finished and start cooling, and use a magnetic tube to pull it out for rapid cooling. A single crystal graphene / copper (111) film covering the substrate is obtained.

[0031] Step 3: The single crystal graphene / copper (111) film is placed in a 0.5 mol / L ferric chloride solution for etching, so that the prepared single crystal graphene / copper (111) substrate can be roughened. After etching, the roughness of the substrate is 2-80 nm.

[0032] Step 4: Weigh 60 mg of molecular sieve and 100 mg of tellurium powder, mix them and place them in the first temperature zone of the tube furnace. Place the etched single crystal graphene / copper (111) into the third temperature zone of the tube furnace. Pump down the tube furnace to 2 Pa. After introducing 20 sccm of argon and 10 sccm of hydrogen, the pressure is 29 Pa. Raise the temperature of the first temperature zone of the tube furnace to 450°C for 15 minutes, and raise the temperature of the second and third temperature zones to 200°C and maintain for 1 hour. Cool to room temperature and take out to obtain a single crystal graphene / two-dimensional cuprous telluride heterojunction material covering the substrate.

[0033] Example 2

[0034] A single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and a preparation method thereof, the steps are as follows:

[0035] Step 1: Cut the sapphire substrate into 1×1 cm size and put it into the piranha solution. Heat the piranha solution on a heating table at 90°C for 1 hour. Then take out the sapphire, rinse it repeatedly with deionized water for 5 minutes, blow it dry with a nitrogen gun, put it into the magnetron sputtering chamber, and evacuate it to 5x10 -5Pa, pre-sputtering was carried out first, and then sputtering was carried out. The sputtering conditions were: sputtering time 28 min, sputtering temperature 180 ° C, sputtering pressure 1 Pa, gas flow rate 20 sccm, sputtering power 100 W. Finally, when the sample cooled to room temperature, the sample was taken out from the magnetron sputtering chamber to obtain a copper (111) thin film with a thickness of 500 nm.

[0036] Step 2: Place the sputtered copper (111) film in the second temperature zone of the tube furnace, pump down the tube furnace to 2Pa, introduce 150sccm argon and 10sccm hydrogen to a pressure of 51Pa, heat the tube furnace to 980°C for 50min and keep it for 30min, then introduce 2sccm methane and keep it for 20min, stop introducing methane after the reaction is finished and start cooling, and use a magnetic tube to pull it out for rapid cooling. A single crystal graphene / copper (111) film covering the substrate is obtained.

[0037] Step 3: The single crystal graphene / copper (111) film is placed in a 0.5 mol / L ferric chloride solution for etching, so that the prepared single crystal graphene / copper (111) substrate can be roughened. After etching, the roughness of the substrate is 2-80 nm.

[0038] Step 4: Weigh 20 mg of molecular sieve and 30 mg of tellurium powder, mix them and place them in the first temperature zone of the tube furnace. Place the etched single crystal graphene / copper (111) into the third temperature zone of the tube furnace. Pump down the tube furnace to 2 Pa. After introducing 20 sccm of argon and 10 sccm of hydrogen, the pressure is 12 Pa. Raise the temperature of the first temperature zone of the tube furnace to 450°C for 10 minutes, and raise the temperature of the second and third temperature zones to 150°C and maintain for 20 minutes. Cool to room temperature and take out to obtain a single crystal graphene / two-dimensional cuprous telluride heterojunction material covering the substrate.

[0039] Example 3

[0040] A single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and a preparation method thereof, the steps are as follows:

[0041] Step 1: Cut the sapphire substrate into 1×1 cm size and put it into the piranha solution. Heat the piranha solution on a heating table at 90°C for 1 hour. Then take out the sapphire, rinse it repeatedly with deionized water for 5 minutes, blow it dry with a nitrogen gun, put it into the magnetron sputtering chamber, and evacuate it to 5x10 -5 Pa, pre-sputtering was carried out first, and then sputtering was carried out. The sputtering conditions were: sputtering time 32 min, sputtering temperature 180 ° C, sputtering pressure 1 Pa, gas flow rate 20 sccm, sputtering power 100 W. Finally, when the sample cooled to room temperature, the sample was taken out from the magnetron sputtering chamber to obtain a copper (111) thin film with a thickness of 800 nm.

[0042] Step 2: Place the sputtered copper (111) film in the second temperature zone of the tube furnace, pump down the tube furnace to 2Pa, introduce 150sccm argon and 10sccm hydrogen to a pressure of 51Pa, heat the tube furnace to 1020°C for 50min and keep it for 30min, then introduce 2sccm methane and keep it for 20min, stop introducing methane after the reaction is finished and start cooling, and use a magnetic tube to pull it out for rapid cooling. A single crystal graphene / copper (111) film covering the substrate is obtained.

[0043] Step 3: The single crystal graphene / copper (111) film is placed in a 0.5 mol / L ferric chloride solution for etching, so that the prepared single crystal graphene / copper (111) substrate can be roughened. After etching, the roughness of the substrate is 2-80 nm.

[0044] Step 4: Weigh 300 mg of molecular sieve and 500 mg of tellurium powder, mix them and place them in the first temperature zone of the tube furnace. Place the etched single crystal graphene / copper (111) into the third temperature zone of the tube furnace. Pump down the tube furnace to 2 Pa. After introducing 20 sccm of argon and 10 sccm of hydrogen, the pressure is 32 Pa. Raise the temperature of the first temperature zone of the tube furnace to 500°C in 20 minutes, and raise the temperature of the second and third temperature zones to 210°C and maintain them for 1.5 hours. Cool them to room temperature and take them out to obtain a single crystal graphene / two-dimensional cuprous telluride heterojunction material covering the substrate.

[0045] Example 4

[0046] A single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and a preparation method thereof, the steps are as follows:

[0047] Step 1: Cut the sapphire substrate into 1×1 cm size and put it into the piranha solution. Heat the piranha solution on a heating table at 90°C for 1 hour. Then take out the sapphire, rinse it repeatedly with deionized water for 5 minutes, blow it dry with a nitrogen gun, put it into the magnetron sputtering chamber, and evacuate it to 5x10 -5 Pa, pre-sputtering was carried out first, and then sputtering was carried out. The sputtering conditions were: sputtering time 40 min, sputtering temperature 180 ° C, sputtering pressure 1 Pa, gas flow rate 20 sccm, sputtering power 100 W. Finally, when the sample cooled to room temperature, the sample was taken out from the magnetron sputtering chamber to obtain a copper (111) thin film with a thickness of 1500 nm.

[0048] Step 2: Place the sputtered copper (111) film in the second temperature zone of the tube furnace, pump down the tube furnace to 2Pa, introduce 150sccm argon and 10sccm hydrogen to a pressure of 51Pa, heat the tube furnace to 1030°C for 50min and keep it for 30min, then introduce 2sccm methane and keep it for 20min, stop introducing methane after the reaction is finished and start cooling, and use a magnetic tube to pull it out for rapid cooling. A single crystal graphene / copper (111) film covering the substrate is obtained.

[0049] Step 3: The single crystal graphene / copper (111) film is placed in a 0.5 mol / L ferric chloride solution for etching, so that the prepared single crystal graphene / copper (111) substrate can be roughened. After etching, the roughness of the substrate is 2-80 nm.

[0050] Step 4: Weigh 500 mg of molecular sieve and 1000 mg of tellurium powder, mix them and place them in the first temperature zone of the tube furnace. Place the etched single crystal graphene / copper (111) into the third temperature zone of the tube furnace. Pump down the tube furnace to 2 Pa. After introducing 20 sccm of argon and 10 sccm of hydrogen, the pressure is 39 Pa. Raise the temperature of the first temperature zone of the tube furnace to 550°C in 25 minutes, and raise the temperature of the second and third temperature zones to 230°C and maintain for 2 hours. Cool to room temperature and take out to obtain a single crystal graphene / two-dimensional cuprous telluride heterojunction material covering the substrate.

[0051] Example 5

[0052] A single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate and a preparation method thereof, the steps are as follows:

[0053] Step 1: Cut the sapphire substrate into 1×1 cm size and put it into the piranha solution. Heat the piranha solution on a heating table at 90°C for 1 hour. Then take out the sapphire, rinse it repeatedly with deionized water for 5 minutes, blow it dry with a nitrogen gun, put it into the magnetron sputtering chamber, and evacuate it to 5x10 -5 Pa, pre-sputtering was carried out first, and then sputtering was carried out. The sputtering conditions were: sputtering time 40 min, sputtering temperature 180 ° C, sputtering pressure 1 Pa, gas flow rate 20 sccm, sputtering power 100 W. Finally, when the sample cooled to room temperature, the sample was taken out from the magnetron sputtering chamber to obtain a copper (111) thin film with a thickness of 1500 nm.

[0054] Step 2: Place the sputtered copper (111) film in the second temperature zone of the tube furnace, pump down the tube furnace to 2Pa, introduce 150sccm argon and 10sccm hydrogen to a pressure of 51Pa, heat the tube furnace to 1030°C for 50min and keep it for 30min, then introduce 2sccm methane and keep it for 20min, stop introducing methane after the reaction is finished and start cooling, and use a magnetic tube to pull it out for rapid cooling. A single crystal graphene / copper (111) film covering the substrate is obtained.

[0055] Step 3: The single crystal graphene / copper (111) film is placed in a 0.5 mol / L ferric chloride solution for etching, so that the prepared single crystal graphene / copper (111) substrate can be roughened. After etching, the roughness of the substrate is 2-80 nm.

[0056] Step 4: Weigh 2000 mg of molecular sieve and 4000 mg of tellurium powder, mix them and place them in the first temperature zone of the tube furnace. Place the etched single crystal graphene / copper (111) into the third temperature zone of the tube furnace. Pump down the tube furnace to 2 Pa. After introducing 20 sccm of argon and 10 sccm of hydrogen, the pressure is 100 Pa. Raise the temperature of the first temperature zone of the tube furnace to 600°C in 30 minutes, and raise the temperature of the second and third temperature zones to 250°C and maintain them for 4 hours. Cool them to room temperature and take them out to obtain a single crystal graphene / two-dimensional cuprous telluride heterojunction material covering the substrate.

Claims

1. A method for preparing a single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate, characterized in that: Here are the steps: (1) Preparation of copper (111) thin films on sapphire (0001) substrates by DC magnetron sputtering; (2) preparing single-crystalline graphene by chemical vapor deposition after envelope coating on the copper (111) film obtained in step (1); (3) placing the single crystal graphene / copper (111) substrate prepared in (2) in a 0.5 mol / L ferric chloride solution for etching to roughen the prepared single crystal graphene / copper (111) substrate; (4) placing the single crystal graphene / copper (111) substrate, tellurium source and molecular sieve after etching in (3) in different temperature zones of a high temperature tube furnace respectively, heating the tube furnace in different temperature zones to different temperatures under certain pressure and carrier gas conditions, and keeping the temperatures for a certain period of time, so that the tellurium source volatilized to the substrate surface reacts with the copper (111) film under the graphene to grow a single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate; The specific operation of preparing single crystal graphene on copper (111) film in step (2) is as follows: the copper (111) film on the sapphire (0001) substrate prepared in (1) is horizontally placed in a high-temperature tube furnace, and the temperature is raised to 980-1030° C. under the conditions of a pressure of 18-200 Pa and a carrier gas flow rate of 10-1000 sccm, the heating time is 10-55 min, the heat preservation time is 20-50 min, and then 0.5-5 sccm of methane is introduced and kept warm for 20-60 min; The roughness of the substrate obtained after etching in step (3) is 2-80 nm; In the step (4), the tellurium source and the molecular sieve are placed in the first temperature zone, and the single crystal graphene / copper (111) substrate is placed in the third temperature zone, and a heat insulation board is used in the middle to form a temperature difference between the two temperature zones; the first temperature zone where the tellurium source is located is heated to 450-600°C and maintained, and the third temperature zone where the single crystal graphene / copper (111) substrate is located is heated to 150-300°C and maintained; In the step (4), the pressure is low pressure or normal pressure, the carrier gas is an inert gas or nitrogen, the carrier gas flow rate is 10sccm-1000sccm, the tellurium source amount is 50-4000mg, the molecular sieve amount is 30-2000mg, the heating time is 10-30min, and the heat preservation time is 20min-4h.

2. The method for preparing the single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate according to claim 1, characterized in that: In the step (1), the copper (111) film is deposited by a DC magnetron sputtering method, the sputtering time is 28-40 minutes, the sputtering temperature is 150-200° C., the sputtering pressure is 0.4-1.2 Pa, the gas flow rate is 20 sccm, the sputtering power is 100 W, and the sputtered copper (111) film thickness is 500 nm-1500 nm.

3. The method for preparing the single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate according to claim 1, characterized in that: The low pressure is 12-100 Pa, and the carrier gas flow rate is 10-500 sccm.

4. The single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate prepared according to any one of claims 1 to 3, characterized in that: The single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate does not need to be transferred, and the lateral size of the heterojunction is 200-6000nm and the thickness is 2-800nm.

5. The use of the single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate according to claim 4 in SERS, characterized in that: The single crystal graphene / two-dimensional cuprous telluride heterojunction SERS substrate is detected with a probe molecule, and a signal of the probe molecule with enhanced signal can be obtained.

6. The use according to claim 5, characterized in that: The probe molecule is Nile red or methylene blue.

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