CN109443630B - Pressure sensor based on QLED light-emitting device - Google Patents

Abstract

The invention provides a pressure sensor based on a QLED light-emitting device, comprising an electrical connection substrate and a functional substrate; the electrical connection substrate and the functional substrate are both PET flexible substrates; the electrical connection substrate is covered with an electrode layer; the functional substrate is covered with an ITO layer; The ITO layer is covered with a functional layer; the functional layer includes multiple layers; the multiple layers of the functional layer sequentially include a hole injection layer, a hole transport layer, a light-emitting layer and an electron transport layer from bottom to top; The functional layer is in contact with the ITO layer of the functional substrate through the hole injection layer; the electron transport layer of the functional layer is closely adjacent to the electrode layer; when the electrical substrate or the functional substrate is pressed, the pressed part deforms so that the electrode layer and the electron transport layer are deformed. When the contact state changes, the charge of the electrode layer reaches the light-emitting layer, so that the light-emitting layer of the pressure-receiving part emits light; the present invention combines the electroluminescence characteristics of the QLED light-emitting device, so that the real-time monitoring of the pressure position is completed through the light signal while conducting the pressure. High repeatability, fast response, strong reliability and simple structure.

Description

A pressure sensor based on QLED light-emitting device

technical field

The invention relates to the technical field of sensors, in particular to a pressure sensor based on a QLED light-emitting device.

Background technique

A sensor is a detection device that can sense the measured information, and can transform the sensed information into electrical signals or other required forms of information output according to certain rules, so as to meet the requirements of information transmission, processing, storage and display. , recording and control requirements. Pressure sensor is the most commonly used sensor in industrial practice. It is widely used in various industrial automation environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automation, and many other industries. However, most of the existing sensors use electrical signals as transmission. medium, which is not easily read directly relative to optical signals.

QLED is a new type of self-luminous display panel. Due to the use of quantum dots as luminescent materials, it has the characteristics of wide color gamut and high color purity, and the QLED display has short response time, high luminous efficiency, low driving voltage, and bendable characteristics. become the next mainstream flat panel display.

In view of the advantages of the above pressure sensor and QLED, in the prior art, a solution method is used to prepare a QLED light-emitting device, so that the real-time position monitoring of the pressure is completed through the optical signal while conducting the pressure, with high repeatability, fast response speed and strong reliability. ,Simple structure.

In view of the problems existing in the above technologies, the present invention aims to provide a pressure sensor with easier signal transmission, so as to solve the deficiencies in the prior art.

SUMMARY OF THE INVENTION

The present invention proposes a pressure sensor based on a QLED light-emitting device, which combines the electroluminescence characteristics of the QLED light-emitting device, so that the real-time monitoring of the pressure position is completed through the optical signal while conducting the pressure, with high repeatability, fast response speed and reliability. Strong and simple in structure.

The present invention adopts the following technical solutions.

A pressure sensor based on a QLED light-emitting device, the pressure sensor includes an electrical substrate and a functional substrate; the electrical substrate and the functional substrate are both PET flexible substrates; the electrical substrate is covered with an electrode layer; the functional substrate The substrate is covered with an ITO layer; the ITO layer is covered with a functional layer; the functional layer includes multiple layers; the multiple layers of the functional layer sequentially include a hole injection layer, a hole transport layer, Light-emitting layer and electron transport layer; the functional layer is in contact with the ITO layer of the functional substrate through the hole injection layer; the electron transport layer of the functional layer is close to the electrode layer; when the electrical substrate or the functional substrate is pressed, the pressed part deforms The contact state between the electrode layer and the electron transport layer is changed, and the charge of the electrode layer reaches the light-emitting layer, so that the light-emitting layer at the pressure-receiving part emits light.

The preparation process of the pressure sensor includes the preparation of functional substrates, the preparation of electrical substrates, and the assembly of substrates;

The preparation process of the functional substrate sequentially includes the following operations;

S1. Preprocess the PET flexible substrate covered with ITO;

S2. Each layer of the functional layer is formed on the PET flexible substrate by spin coating or blade coating; the functional substrate is made;

The preparation of the electrical connection substrate includes the following operations;

S3: forming a metal electrode by a coating process or forming a thin film electrode by a spin coating/blade coating process on the PET flexible substrate without ITO coating;

The substrate assembly includes the following operations;

S4: Invert the flexible PET substrate with electrodes attached to the PET substrate on which each functional layer has been formed, and fix it with packaging materials around it.

The pretreatment of the ITO-coated PET flexible substrate includes cleaning treatment and plasma treatment.

The process for forming the metal electrode is evaporation coating, the process for forming the thin film electrode is a spin coating process or a blade coating process, and the thin film electrode is a metal nanowire thin film electrode.

Each layer of the functional layer is in the form of a film; each layer of the functional layer is formed by spin coating or blade coating.

The light-emitting layer emits light with a QLED light-emitting element; the QLED light-emitting element is a quantum dot.

The square resistance of the ITO layer of the functional substrate is 320 Ω/□.

The electrode layer on the electrical connection substrate is a silver electrode layer formed by a coating process.

The thickness of the silver electrode layer is in the range of 100-200 nm.

The hole injection layer is prepared by spin coating with PEDOT:PSS solution; the hole transport layer is prepared by spin coating with TFB solution; the light emitting layer is prepared by spin coating with quantum dot solution; the electron transport layer is prepared by spin coating with quantum dot solution; The layers were prepared by spin coating of zinc oxide nanoparticle solutions.

The advantages of the present invention are:

1) The new pressure sensor of the present invention utilizes the electroluminescence characteristics of the QLED light-emitting device, so that the real-time pressure position monitoring can be completed by emitting light while conducting pressure. The response speed is fast and the structure is simple. It is not easy to read the pressure position. It provides the feasibility of monitoring the pressure position under the closed environmental conditions.

2) The novel pressure sensor of the present invention obtains each functional layer by a selective coating method and obtains a metal electrode by an evaporation coating method, and has a simple structure, high repeatability, strong reliability and easy operation.

Description of drawings

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments:

Accompanying drawing 1 is the working principle schematic diagram of the present invention;

Accompanying drawing 2 is the structural representation of the present invention;

In the figure: 110 - functional substrate; 120 - hole injection layer; 130 - hole transport layer; 140 - light emitting layer; 150 - electron transport layer; 160 - electrode layer; A closed pressure vessel for the invention of the pressure sensor; 190-pressure sensor.

Detailed ways

As shown in FIG. 1-2, a pressure sensor based on a QLED light-emitting device, the pressure sensor includes an electrical substrate 170 and a functional substrate 110; the electrical substrate 170 and the functional substrate 110 are both PET flexible substrates; the The electrode layer 160 is covered on the electrical substrate; the functional substrate is covered with an ITO layer; the ITO layer is covered with a functional layer; the functional layer includes multiple layers; the multiple layers of the functional layer are from bottom to top The upper layer includes a hole injection layer 120, a hole transport layer 130, a light-emitting layer 140 and an electron transport layer 150 in sequence; the functional layer is in contact with the ITO layer of the functional substrate through the hole injection layer; the electron transport layer of the functional layer and the electrode layer Immediately adjacent; when the electrical substrate or functional substrate is pressed, the deformation of the pressed part makes the contact state between the electrode layer and the electron transport layer change, and the charge of the electrode layer reaches the light-emitting layer, so that the light-emitting layer of the pressed part emits light.

The preparation process of the pressure sensor includes the preparation of functional substrates, the preparation of electrical substrates, and the assembly of substrates;

The preparation process of the functional substrate sequentially includes the following operations;

S1. Preprocess the PET flexible substrate covered with ITO;

S2. Each layer of the functional layer is formed on the PET flexible substrate by spin coating or blade coating; the functional substrate is made;

The preparation of the electrical connection substrate includes the following operations;

S3: forming a metal electrode by a coating process or forming a thin film electrode by a spin coating/blade coating process on the PET flexible substrate without ITO coating;

The substrate assembly includes the following operations;

S4: Invert the flexible PET substrate with electrodes attached to the PET substrate on which each functional layer has been formed, and fix it with packaging materials around it.

The pretreatment of the ITO-coated PET flexible substrate includes cleaning treatment and plasma treatment.

The process for forming the metal electrode is evaporation coating, the process for forming the thin film electrode is a spin coating process or a blade coating process, and the thin film electrode is a metal nanowire thin film electrode.

Each layer of the functional layer is in the form of a film; each layer of the functional layer is formed by spin coating or blade coating.

The light-emitting layer emits light with a QLED light-emitting element; the QLED light-emitting element is a quantum dot.

The square resistance of the ITO layer of the functional substrate is 320 Ω/□.

The electrode layer on the electrical connection substrate is a silver electrode layer formed by a coating process.

The thickness of the silver electrode layer is in the range of 100-200 nm.

The hole injection layer is prepared by spin coating with PEDOT:PSS solution; the hole transport layer is prepared by spin coating with TFB solution; the light emitting layer is prepared by spin coating with quantum dot solution; the electron transport layer is prepared by spin coating with quantum dot solution; The layers were prepared by spin coating of zinc oxide nanoparticle solutions.

In this example, in step S2, the PEDOT:PSS solution was spin-coated at a rotation speed of 3000r on the PET flexible substrate, and annealed at a temperature of 120 degrees for 20 minutes; the TFB solution was spin-coated at a rotation speed of 3000r, and annealed at a temperature of 120 degrees for 20 minutes. min; spin-coating green quantum dot solution at 2000r and annealing at 65 degrees for 15 minutes; spin-coating zinc oxide nanoparticle solution at 1700r and annealing at 65 degrees for 20 minutes.

The hole transport layer was prepared by dissolving in a TFB solution with a concentration of 8 mg/ml in chlorobenzene, the light-emitting layer was prepared by dissolving a green quantum dot solution with a concentration of 15 mg/ml in n-octane, and the electron transport layer was prepared by dissolving in a solution of 6 mg/ml oxidized n-octane. Zinc Nanoparticle Solution Preparation.

In implementation, the quantum dots as light-emitting materials can also be selected from red quantum dots, green quantum dots and blue quantum dots, which are selected from one or more of II-VI or III-V groups.

As shown in Figure 1, after the sensor of the present invention is placed in a pressure vessel, when the pressure vessel is filled with pressure gas or liquid, the pressure sensor is pressurized, and when the pressure rises to a preset value, the electrode layer and the electron transport layer are formed. Contact, the charge of the electrode layer reaches the light-emitting layer, so that the light-emitting layer at the pressure-receiving part emits light. After the observer observes the sensor light-emitting through the transparent container wall, it can be considered that the pressure in the pressure container is not lower than the preset value.

Claims (10)

1. A pressure sensor based on a QLED light-emitting device, characterized in that: the pressure sensor comprises an electrical substrate (170) and a functional substrate (110); the electrical substrate and the functional substrate are both PET flexible substrates; the An electrode layer (160) is covered on an electrical connection substrate; an ITO layer is covered on the functional substrate; a functional layer is covered on the ITO layer; the functional layer includes a plurality of layers; It includes a hole injection layer (120), a hole transport layer (130), a light emitting layer (140) and an electron transport layer (150) in sequence from bottom to top; the functional layer is in contact with the ITO layer of the functional substrate through the hole injection layer ; The electron transport layer of the functional layer is close to the electrode layer; when the electrical substrate or the functional substrate is pressed, the deformation of the pressed part causes the contact state between the electrode layer and the electron transport layer to change, and the charge of the electrode layer reaches the light-emitting layer, making the pressure-receiving part change. The light-emitting layer emits light; When used for pressure detection, the electrode layer can contact the electron transport layer only after the pressure reaches a preset value, so that the pressure sensor emits light. 2. A pressure sensor based on a QLED light-emitting device according to claim 1, wherein the preparation process of the pressure sensor comprises the preparation of functional substrates, the preparation of electrical substrates, and the assembly of substrates; The preparation process of the functional substrate sequentially includes the following operations; S1. Preprocess the PET flexible substrate covered with ITO; S2. Each layer of the functional layer is formed on the PET flexible substrate by spin coating or blade coating; the functional substrate is made; The preparation of the electrical connection substrate includes the following operations; S3: forming a metal electrode by a coating process or forming a thin film electrode by a spin coating/blade coating process on the PET flexible substrate without ITO coating; The substrate assembly includes the following operations; S4: Invert the flexible PET substrate with electrodes attached to the PET substrate on which each functional layer has been formed, and fix it with packaging materials around it. 3 . The pressure sensor based on a QLED light-emitting device according to claim 2 , wherein the pretreatment of the ITO-coated PET flexible substrate includes cleaning treatment and plasma treatment. 4 . 4. A pressure sensor based on a QLED light-emitting device according to claim 2, wherein the process for forming the metal electrode is evaporation coating, and the process for forming the thin film electrode is a spin coating process or a blade coating process, The thin film electrodes are metal nanowire thin film electrodes. 5. A pressure sensor based on a QLED light-emitting device according to claim 1, characterized in that: each layer of the functional layer is in a film shape; each layer of the functional layer adopts a spin coating or blade coating method forming. 6 . The pressure sensor based on a QLED light-emitting device according to claim 1 , wherein the light-emitting layer emits light with a QLED light-emitting element; and the QLED light-emitting element is a quantum dot. 7 . 7 . The pressure sensor based on a QLED light-emitting device according to claim 1 , wherein the square resistance of the ITO layer of the functional substrate is 320 Ω/□. 8 . 8 . The pressure sensor based on a QLED light-emitting device according to claim 1 , wherein the electrode layer on the electrical connection substrate is a silver electrode layer formed by a coating process. 9 . 9 . The pressure sensor based on a QLED light-emitting device according to claim 8 , wherein the thickness of the silver electrode layer ranges from 100 to 200 nm. 10 . 10. A pressure sensor based on a QLED light-emitting device according to claim 1, wherein the hole injection layer is prepared by spin coating with PEDOT:PSS solution; the hole transport layer is spin-coated with a TFB solution. Preparation by coating into a film; the light-emitting layer is prepared by spin coating with a quantum dot solution; the electron transport layer is prepared by spin coating with a zinc oxide nanoparticle solution.

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