CN115440888A - Flexible vertical channel field effect transistor based on metal and dielectric mixed thin film source electrode - Google Patents

Abstract

The invention discloses a flexible vertical channel field effect transistor based on a metal and dielectric mixed thin film source electrode, which sequentially comprises a flexible substrate, a grid electrode, a grid medium, a metal and dielectric mixed thin film source electrode, a semiconductor active layer and a drain electrode from bottom to top; the metal and dielectric mixed film is prepared by adopting the aspects of vacuum co-evaporation, vacuum co-sputtering, solution spin coating and sol-gel; the conductive properties and dielectric properties of the metal and dielectric mixed film are adjusted by changing the weight ratio of the metal to the dielectric in the mixed film. The invention has the advantages of simple preparation process, easy improvement of device performance by changing the weight mixing ratio of metal and dielectric in the mixed film, and the like, and is relatively suitable for large-scale production.

Description

A Flexible Vertical Channel Field Effect Based on Metal and Dielectric Mixed Thin Film Source Should manage

【Technical field】

The invention relates to the field of preparation of optoelectronic devices, in particular to a flexible vertical channel field effect transistor based on metal and dielectric mixed film source.

【Background technique】

Compared with the horizontal channel phototransistor, the popular vertical structure phototransistor in recent years has shown better photoelectric performance, which is due to its ultra-short channel length, which makes the photogenerated hole transfer distance shorter and the exciton dissociation The electric field is stronger, so that the device with vertical structure has higher responsivity and good specific detectivity, as well as fast photoresponse time. Therefore, the vertical channel phototransistor has become one of the research hotspots of organic electronic devices. Among them, the design and manufacturing process of the source of the vertical channel organic phototransistor is one of the key research points at this stage. In order to achieve low-cost and high-performance devices, there are currently many preparation methods. One of them is the preparation of structural film layers. This method first spin-coats the prepared solution, followed by photolithography of the film layer, which provides an effective method for embedding electronic functional layers into the substrate, but in such devices, there are usually Dielectric breakdown under high negative gate bias, therefore, the devices prepared by this method are more suitable for positive gate bias. The other is a graphene-based preparation method. This method transfers graphene grown by chemical vapor deposition to the surface of a chemically cleaned substrate to prepare a graphene source electrode, and then spin-coats functional materials on the graphene surface to form a photosensitive electrode. channel layer, followed by thermal evaporation of other layers to make the device, which takes advantage of graphene's unique structural advantages, but the technology to put the device into a large-scale underlying integrated circuit without loss of performance is still immature . There is also a method for preparing silver nanowires and gold/silver nanowires. In the silver nanowire method, silver nanowires as transparent source electrodes are spin-coated on the substrate, and then the thermal evaporation electrodes are connected to the nanowires, and finally the active layer is spun Apply to substrate. The gold/silver nanowire method requires self-assembly and preparation of solutions to obtain nanowires. Other steps are similar to silver nanowires. The method of preparing nanowires can reduce the critical size of the device, but because the nanowires need to be self-prepared, it is difficult to integrate It is difficult to quantify the convenience of production. The last one is the laser etching method. This method forms a patterned film layer by laser etching the source to enhance the performance of the device. However, due to the need for an operating table and a laser, there are certain requirements for the preparation conditions.

【Content of invention】

The purpose of the present invention is to provide a vertical trench field effect transistor with metal and dielectric mixed film as the source and its preparation method, so as to solve the defects of complicated preparation process or poor repeatability of the current vertical trench field effect transistor.

The purpose of the present invention is achieved in this way: a vertical channel field effect transistor using a metal and dielectric mixed film to prepare the source electrode, including a substrate, a gate, a gate dielectric layer, and a metal and dielectric mixed film arranged in sequence from bottom to top Source, semiconductor active layer and drain; The semiconductor active layer is characterized in that it is an inorganic semiconductor, an organic semiconductor, a perovskite semiconductor and a two-dimensional semiconductor film; the metal and dielectric mixed film source is characterized in that It is composed of metal nanoparticles and dielectric nanoparticles. Its conductive and dielectric properties can be adjusted by the weight mixing ratio of metal and dielectric. Its preparation methods include vacuum thermal co-evaporation, co-sputtering, sol-gel and solution spin coating.

As a further limitation of the present invention, the thickness of the gate dielectric layer is 100-2000 nm.

As a further limitation of the present invention, the thickness of the flexible semiconductor active layer is 10-1000 nm.

A method for preparing a flexible vertical trench field effect transistor based on a metal and dielectric mixed film source, comprising the following steps:

Step 1: Clean the substrate with detergent, acetone solution, deionized water and isopropanol solution, and dry it with nitrogen after cleaning;

Step 2: preparing the gate on the surface of the substrate;

Step 3: preparing a gate dielectric layer on the surface of the gate electrode;

Step 4: preparing metal and dielectric mixed film source on the gate dielectric layer;

Step 5: preparing a flexible semiconductor active layer on the metal and dielectric mixed film source;

Step 7: Prepare a drain on the semiconductor active layer.

As a further limitation of the present invention, in the step 3, the gate dielectric layer is prepared by one of vacuum sputtering, vacuum thermal evaporation, solution spin coating, sol-gel, embossing and spray coating.

As a further limitation of the present invention, in the step 2 and step 7, the gate and the drain are prepared by one of vacuum thermal evaporation, magnetron sputtering or spin coating.

【Description of drawings】

FIG. 1 is a schematic diagram of the structure of a flexible vertical channel field effect transistor device based on a mixed metal and dielectric thin film source according to the present invention.

FIG. 2 is a schematic diagram of the structure of the source in the device shown in the present invention.

【detailed description】

In order to make the objects and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific examples described here are only used to explain the present invention, and are not intended to limit the scope of the claims of the present invention. Various materials and reagents involved in the examples can be purchased through commercial channels.

Example 1:

The flexible vertical trench field effect transistor structure shown in Figure 1, the material and thickness of each layer are: the flexible substrate is polyethylene terephthalate (PET), 2000nm; the gate is ITO, 100nm; the source is gold nano A mixed film of particles and LiF nanoparticles, 100nm; a semiconductor active film of copper phthalocyanine, 100nm; a drain of Al thin film, 100nm. The structure can realize high-performance flexible vertical trench field effect transistor.

The steps for preparing the above-mentioned flexible vertical trench field effect transistor are as follows:

1. Clean the substrate with detergent, acetone solution, deionized water and isopropanol solution, and dry it with nitrogen after cleaning;

2. Prepare the ITO gate electrode on the surface of the substrate;

3. prepare polyvinyl alcohol (PVA) dielectric layer with solution method above described gate electrode;

4. On the surface of polyvinyl alcohol (PVA) dielectric layer, prepare the mixed film of 100nm gold particle and LiF particle with vacuum cothermal evaporation method;

6. Prepare a 100nm copper phthalocyanine flexible semiconductor active layer by vacuum thermal evaporation on the metal-dielectric mixed film source;

7. Prepare a 100nm aluminum thin film drain electrode on the flexible semiconductor active layer by vacuum thermal evaporation.

Claims (5)

1. A flexible vertical channel field effect transistor based on a metal and dielectric mixed thin film source electrode is composed of a flexible substrate, a grid electrode, a grid medium, a metal and dielectric mixed thin film source electrode, a semiconductor active layer and a drain electrode from bottom to top, and is characterized in that the substrate is rigid or flexible; the grid electrode and the drain electrode are conductive films.

2. The flexible vertical channel field effect transistor based on a metal and dielectric mixed thin film source electrode as claimed in claim 1 wherein the semiconducting active layer is a flexible inorganic semiconductor, an organic semiconductor, a flexible perovskite semiconductor and a two dimensional semiconductor.

3. The flexible vertical channel field effect transistor based on a metal and dielectric mixed thin film source electrode as claimed in claim 1, wherein the metal and dielectric mixed thin film is composed of metal nanoparticles and dielectric nanoparticles.

4. The flexible vertical channel field effect transistor based on metal and dielectric mixed thin film source as claimed in claim 1 wherein the metal and dielectric mixed thin film is prepared by vacuum thermal co-evaporation, co-sputtering and solution spin coating methods.

5. The flexible vertical channel field effect transistor based on a metal and dielectric mixed thin film source electrode as claimed in claim 1, wherein the conducting property and dielectric property of the metal and dielectric mixed thin film can be adjusted by the weight mixing ratio of the metal and the dielectric.

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