Polypyrrole@graphene / semiconductor heterostructure and preparation method and application thereof

Abstract

The present invention relates to a polypyrrole@graphene / semiconductor heterostructure and a preparation method and application thereof, comprising the following steps: step 1, preparation of a polypyrrole@graphene composite structure; step 2, preparation of a polypyrrole@graphene / semiconductor heterostructure. The polypyrrole@graphene coated structure prepared by the present invention has greatly improved performance compared with pure polypyrrole, and its carrier concentration and carrier mobility values ​​are significantly improved, and it forms a heterostructure with other semiconductors, which can significantly improve device performance.

Description

Technical Field

[0001] The invention relates to a method for preparing a conductive polypyrrole@graphene / semiconductor photoelectric detector, and in particular to a method for preparing a polypyrrole graphene composite structure by a chemical method and then combining the composite structure with a semiconductor to form a heterostructure. Background Art

[0002] Conductive polymers are a type of conductive polymer material. In addition to the advantages of traditional polymer materials such as light weight, easy processing, good mechanical properties and low cost, related reports show that conductive polymers have great application prospects in organic solar cells, organic light-emitting diodes, electrochromic, supercapacitors, chemical sensors and biosensors, flexible transparent displays and electromagnetic shielding. Polypyrrole (PPy) is one of the common conductive polymers and has been widely studied in the preparation of capacitor electrodes and photodetection devices.

[0003] Since its discovery, graphene has attracted extensive research attention due to its excellent optical, electrical and mechanical properties. Experimental measurements show that the carrier mobility of graphene at room temperature can reach 15,000 cm 2 V -1 s -1 , is an excellent conductive material. Combining it with other materials can effectively improve the electrical properties of the material. Summary of the invention

[0004] The present invention designs a polypyrrole@graphene / semiconductor heterostructure and its preparation method and application, which solves the technical problem that the existing polypyrrole / semiconductor structure photodetector has poor ultraviolet response peak, light-to-dark current ratio and response time parameters and limited performance.

[0005] In order to solve the above-mentioned technical problems, the present invention adopts the following solutions:

[0006] A method for preparing a polypyrrole@graphene / semiconductor heterostructure comprises the following steps: step 1, preparing a polypyrrole@graphene composite structure; step 2, preparing a polypyrrole@graphene / semiconductor heterostructure.

[0007] Preferably, the preparation of the polypyrrole@graphene composite structure in step 1 includes the following: step 11, preparing a protonic acid solution, using deionized water as a solvent; step 12, weighing an oxidant and dissolving it in the above-mentioned protonic acid solution, and stirring it thoroughly to make it completely dissolved; step 13, cutting a certain area of ​​copper foil graphene, placing it in the above-mentioned acid solution containing the oxidant, so that the copper substrate is dissolved, and the remaining graphene floats on the liquid surface; step 14, sucking pyrrole monomer with a straw, dripping it on the graphene, waiting for a certain period of time to obtain a polypyrrole-wrapped graphene composite structure material, and the solution is kept at a constant temperature during the reaction.

[0008] Preferably, the protonic acid in step 11 is hydrochloric acid, sulfuric acid, perchloric acid, dodecylbenzenesulfonic acid or camphorsulfonic acid, and the pH value of the protonic acid solution is in the range of 0.5-3.

[0009] Preferably, the oxidant in step 12 is any one of ammonium persulfate, potassium permanganate, hydrogen peroxide or ferric chloride, and the concentration of the oxidant in the acid solution is in the range of 0.01-0.1 mol / L.

[0010] Preferably, the reaction time in step 14 is in the range of 1-60 min.

[0011] Preferably, the reaction temperature in step 14 is selected to be in the range of 0-60°C.

[0012] Preferably, step 2: preparation of polypyrrole@graphene / semiconductor heterostructure includes the following: step 21, transferring the polypyrrole-wrapped graphene composite structure material prepared in step 1 to deionized water for immersion to remove surface impurities; step 22, covering the cleaned composite structure material on the semiconductor and drying it; step 23, preparing ohmic contact electrodes on the composite structure material and the semiconductor respectively, and a polypyrrole@graphene / semiconductor heterostructure pyrrole conductive film can be obtained.

[0013] Preferably, in step 22, the semiconductor form includes single crystal, thin film or low-dimensional material.

[0014] Preferably, the semiconductor in step 22 is SnO2.

[0015] A high-crystalline quality polypyrrole conductive film prepared by the above preparation method,

[0016] A photoelectric ultraviolet detection device is characterized by comprising the above-mentioned high crystalline quality polypyrrole conductive film.

[0017] The polypyrrole@graphene / semiconductor heterostructure and its preparation method and application have the following beneficial effects:

[0018] (1) The polypyrrole@graphene coating structure prepared by the present invention has greatly improved performance compared with pure polypyrrole, and its carrier concentration and carrier mobility values ​​are significantly improved. It forms a heterostructure with other semiconductors, which can significantly improve device performance.

[0019] (2) The performance of the polypyrrole@graphene / semiconductor heterojunction photodetector device prepared by the present invention is significantly improved compared with the performance of the device without graphene.

[0020] (3) In the present invention, the graphene with copper substrate is first placed on a protonic acid solution containing an oxidant to dissolve the copper, and then the pyrrole monomer is dropped onto the graphene surface to diffuse it and form a coating structure around the graphene. It is then combined with a semiconductor material to form a heterostructure, and this structure can be used to realize a semiconductor functional device. By introducing graphene, the effective transport of hole carriers can be effectively improved, and the device performance can be significantly improved. The device performance obtained by this method is better than the existing polypyrrole / semiconductor structure photodetector. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the preparation process of the polypyrrole@graphene composite structure in 1 of the present invention;

[0022] Figure 2 This is a microscope image of the polypyrrole@graphene / SnO2 micron-wire heterojunction device in the present invention;

[0023] Figure 3 The photoresponsivity spectra of the polypyrrole@graphene / SnO2 and polypyrrole / SnO2 structures in the present invention;

[0024] Figure 4 This is a graph showing the current variation with light for the polypyrrole@graphene / SnO2 and polypyrrole / SnO2 structures of the present invention. DETAILED DESCRIPTION

[0025] Combine the following Figures 1 to 3 , the present invention is further described:

[0026] The preparation method of the polypyrrole@graphene / semiconductor heterostructure of the present invention comprises the following steps: Step 1, preparation of the polypyrrole@graphene composite structure:

[0027] Step 11. Use a measuring cylinder to measure 99 mL of deionized water and pour it into a beaker. Then use a pipette to measure 833 μL of 12 mol / L concentrated hydrochloric acid solution and add it to the deionized water to prepare a hydrochloric acid aqueous solution with a pH of 1.

[0028] Step 12: Weigh 0.228 g of ammonium persulfate solid, dissolve it in the dilute hydrochloric acid solution prepared above, and stir to fully dissolve it. The concentration of ammonium persulfate is 0.01 mol / L.

[0029] Step 13, cutting a 1 cm×1 cm copper-based N-doped graphene, placing the copper substrate downward on the surface of the protonic acid solution containing the oxidant, so that the copper substrate is dissolved and the graphene floats on the liquid surface;

[0030] Step 14: After the copper is completely corroded, use a pipette to measure 5 μL of pyrrole monomer and drop it on the graphene surface to allow it to diffuse naturally. The reaction is carried out at room temperature and wait for 10 minutes to obtain a polypyrrole@graphene coated composite structure material.

[0031] Step 2: Preparation of polypyrrole@graphene / semiconductor heterostructures:

[0032] Step 21: Fix the SnO2 micron wire on a clean quartz glass substrate.

[0033] Step 22: Transfer the composite structure material prepared in step 1 into deionized water and soak it for several tens of minutes to remove surface impurities.

[0034] Step 23: Cover the cleaned composite structure material on SnO2 and put it into an oven for drying at a temperature of 60° C. for 60 minutes.

[0035] Step 24: Apply a proper amount of silver paste on the composite structure material and dry it as an ohmic contact electrode, and press indium particles on SnO2 as an ohmic contact electrode to obtain a polypyrrole@graphene / SnO2 heterostructure.

[0036] Results analysis: see Figure 1-4 :

[0037] Figure 1 Schematic diagram of the preparation process of the polypyrrole@graphene composite structure in step 1.

[0038] Figure 2 This is a scanning electron microscope image of the prepared polypyrrole@graphene / SnO2 heterostructure. It can be seen from the image that polypyrrole@graphene is covered on the SnO2 microwire.

[0039] Figure 3 Figure 2 is the photoelectric response spectrum of polypyrrole@graphene / SnO2 heterostructure and polypyrrole / SnO2 structure. It can be seen that the ultraviolet response peak of polypyrrole@graphene / SnO2 heterostructure is 4580 A / W, which is much higher than 115 A / W of polypyrrole / SnO2 structure.

[0040] Figure 4 The current variation spectra of polypyrrole@graphene / SnO2 heterostructure and polypyrrole / SnO2 structure with light illumination. It can be seen that the light-to-dark current ratio and response time of polypyrrole@graphene / SnO2 heterostructure are significantly better than those of polypyrrole / SnO2 structure.

[0041] The polypyrrole@graphene coating structure prepared by the method has excellent electrical properties and can be combined with other semiconductors to prepare heterojunction devices with excellent performance, which can be applied in the field of microelectronics.

[0042] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a polypyrrole@graphene / semiconductor heterostructure, comprising the following steps: Step 1, preparation of polypyrrole@graphene composite structure; Step 1 The preparation of the polypyrrole@graphene composite structure includes the following: Step 11, preparing a protonic acid solution, using deionized water as the solvent; Step 12, weighing an oxidant and dissolving it in the above-mentioned protonic acid solution, stirring it thoroughly to make it completely dissolved; the oxidant in step 12 is any one of ammonium persulfate, potassium permanganate, hydrogen peroxide or ferric chloride, and the concentration of the oxidant in the acid solution is in the range of 0.01-0.1 mol / L; Step 13, cutting a certain area of ​​copper foil graphene, placing it in the above acid solution containing an oxidant, so that the copper substrate is dissolved and the graphene floats on the liquid surface; Step 14, using a straw to absorb pyrrole monomer, dripping it onto graphene, and waiting for a certain period of time to obtain a polypyrrole-wrapped graphene composite structure material, and the solution is kept at a constant temperature during the reaction; Step 2, preparation of polypyrrole@graphene / semiconductor heterostructure; Step 2: Preparation of polypyrrole@graphene / semiconductor heterostructures includes the following: Step 21, fixing the SnO2 micron wire on a clean quartz glass substrate; Step 22, transferring the composite structure material prepared in step 1 into deionized water and soaking it for several tens of minutes to remove surface impurities; Step 23, covering the cleaned composite structure material on SnO2, and placing it in an oven for drying at a temperature of 60°C for 60 minutes; Step 24: Apply a proper amount of silver paste on the composite structure material and dry it as an ohmic contact electrode, and press indium particles on SnO2 as an ohmic contact electrode to obtain a polypyrrole@graphene / SnO2 heterostructure.

2. The method for preparing a polypyrrole@graphene / semiconductor heterostructure according to claim 1, characterized in that: The protonic acid in step 11 is hydrochloric acid, sulfuric acid, perchloric acid, dodecylbenzenesulfonic acid or camphorsulfonic acid, and the pH value of the protonic acid solution ranges from 0.5 to 3.

3. The method for preparing a polypyrrole@graphene / semiconductor heterostructure according to claim 1, characterized in that: The reaction time in step 14 is in the range of 1-60 min, and the reaction temperature in step 14 is in the range of 0-60 °C.

4. A polypyrrole@graphene / semiconductor heterostructure prepared by the preparation method according to any one of claims 1 to 3.

5. A photoelectric ultraviolet detection device, characterized in that: It comprises the polypyrrole@graphene / semiconductor heterostructure as described in claim 4.

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