阅读说明：本技术 一种平板探测器 (Flat panel detector ) 是由 张建华 李意 毛龙妹 于 2020-08-10 设计创作，主要内容包括：本发明涉及一种平板探测器,包括由下至上依次设置的薄膜晶体管组、第一金属电极、转换层和第二金属电极；所述薄膜晶体管组包括n个薄膜晶体管,n为大于等于1的正整数；各所述薄膜晶体管的源极均与所述第一金属电极连接；所述转换层由银纳米线、量子点和闪烁体胶体组成。本发明运用银纳米线具有较高的导电性,能够快速收集并传输自由载流子,降低了工作电压的同时降低了信号读取时间,提高了成像质量。(The invention relates to a flat panel detector, which comprises a thin film transistor group, a first metal electrode, a conversion layer and a second metal electrode, wherein the thin film transistor group, the first metal electrode, the conversion layer and the second metal electrode are sequentially arranged from bottom to top; the thin film transistor group comprises n thin film transistors, wherein n is a positive integer greater than or equal to 1; the source electrode of each thin film transistor is connected with the first metal electrode; the conversion layer is composed of silver nanowires, quantum dots and scintillator colloids. The silver nanowire has high conductivity, can quickly collect and transmit free carriers, reduces working voltage, reduces signal reading time and improves imaging quality.)

1. A flat panel detector is characterized by comprising a thin film transistor group, a first metal electrode, a conversion layer and a second metal electrode which are sequentially arranged from bottom to top;

the thin film transistor group comprises n thin film transistors, wherein n is a positive integer greater than or equal to 1;

the source electrode of each thin film transistor is connected with the first metal electrode;

the conversion layer is composed of silver nanowires, quantum dots and scintillator colloids.

2. The flat panel detector according to claim 1, wherein the conversion layer comprises a first layer, a second layer and a third layer sequentially arranged from bottom to top;

the first layer and the third layer are both composed of the silver nanowires, the quantum dots, and the scintillator colloid; the second layer is composed of the quantum dots and the scintillator colloid.

3. The flat panel detector according to claim 1, wherein the scintillator colloid is any one of cadmium tungstate, cesium iodide and thallium-doped sodium iodide.

4. The flat panel detector of claim 1, wherein the quantum dots are any one of cadmium selenide, silicon, cadmium telluride, and indium phosphide.

5. The flat panel detector according to claim 2, wherein the thickness of the first layer, the second layer and the third layer is 0.01-100 μm.

6. The flat panel detector according to claim 2, wherein the silver nanowires account for 0.01 to 0.3 of the total volume of the first layer, the quantum dots account for 0.01 to 0.3 of the total volume of the first layer, and the scintillator glue accounts for 0.4 to 0.98 of the total volume of the first layer;

the silver nanowires account for 0.01-0.3 of the total volume of the third layer, the quantum dots account for 0.01-0.3 of the total volume of the third layer, and the scintillator glue accounts for 0.4-0.98 of the total volume of the third layer.

7. The flat panel detector according to claim 2, wherein the quantum dots occupy 0.01-0.3 of the total volume of the second layer, and the scintillator gel occupies 0.7-0.99 of the total volume of the second layer.

8. A flat panel detector according to claim 1, further comprising:

and the light reflecting sealing layer is used for performing light reflecting sealing on the four side surfaces of the first metal electrode, the four side surfaces of the conversion layer and the four side surfaces of the second metal electrode.

9. The flat panel detector according to claim 1, wherein the first metal electrode is attached to the thin film transistor group by evaporation; the second metal electrode is attached to the conversion layer by evaporation.

Technical Field

The invention relates to the technical field of digital images, in particular to a flat panel detector.

Background

Digital Radiography (DR) technology has been widely used in the fields of medical instruments and the like due to its advantages of fast imaging, convenient operation, high resolution and the like. Among them, the performance of the X-ray flat panel detector has a relatively large influence on the DR image quality.

At present, an amorphous selenium flat panel detector and an amorphous silicon flat panel detector are the most common commercial DR flat panel detectors, and the former belongs to a direct flat panel detector and the latter belongs to an indirect flat panel detector according to different energy conversion modes. The direct flat panel detector collects current generated by an upper conversion layer through a thin film transistor array at the bottom, reads X-ray dose of each point through a reading circuit, and then generates an image. Since the amorphous selenium does not generate visible light and has no influence of scattered rays, higher spatial resolution can be obtained. But because its operating voltage is high and therefore has the potential safety hazard, in addition have a series of problems such as image overlap and hysteresis. The indirect flat panel detector consists of a scintillator material at the upper part, an amorphous silicon photodiode at the middle part and a charge reading circuit at the bottom part, namely the amorphous silicon photodiode detects visible light converted by the scintillator material absorbing X rays, and the charge reading circuit reads charges and finally converts the charges into images. However, the visible light will scatter during the conversion process, which will have a certain effect on the spatial resolution.

In addition, inorganic absorbing materials are also placed in the organic matrix in the prior art, but the organic semiconductor has lower conductivity, thereby reducing the efficiency of the photodiode and affecting the imaging quality.

Disclosure of Invention

The invention aims to provide a flat panel detector, which is used for improving the conductivity of the flat panel detector and improving the imaging quality.

In order to achieve the purpose, the invention provides the following scheme:

a flat panel detector comprises a thin film transistor group, a first metal electrode, a conversion layer and a second metal electrode which are arranged from bottom to top in sequence;

the thin film transistor group comprises n thin film transistors, wherein n is a positive integer greater than or equal to 1;

the source electrode of each thin film transistor is connected with the first metal electrode;

the conversion layer is composed of silver nanowires, quantum dots and scintillator colloids.

Preferably, the conversion layer comprises a first layer, a second layer and a third layer which are arranged from bottom to top in sequence;

the first layer and the third layer are both composed of the silver nanowires, the quantum dots, and the scintillator colloid; the second layer is composed of the quantum dots and the scintillator colloid.

Preferably, the scintillator colloid is any one of cadmium tungstate, cesium iodide and thallium-doped sodium iodide.

Preferably, the quantum dot is any one of cadmium selenide, silicon, cadmium telluride, and indium phosphide.

Preferably, the thickness of the first layer, the second layer and the third layer ranges from 0.01 to 100 μm.

Preferably, the silver nanowires account for 0.01-0.3 of the total volume of the first layer, the quantum dots account for 0.01-0.3 of the total volume of the first layer, and the scintillator glue accounts for 0.4-0.98 of the total volume of the first layer;

the silver nanowires account for 0.01-0.3 of the total volume of the third layer, the quantum dots account for 0.01-0.3 of the total volume of the third layer, and the scintillator glue accounts for 0.4-0.98 of the total volume of the third layer.

Preferably, the quantum dots account for 0.01-0.3 of the total volume of the second layer, and the scintillator colloid accounts for 0.7-0.99 of the total volume of the second layer.

Preferably, the flat panel detector further includes:

and the light reflecting sealing layer is used for performing light reflecting sealing on the four side surfaces of the first metal electrode, the four side surfaces of the conversion layer and the four side surfaces of the second metal electrode.

Preferably, the first metal electrode is attached to the thin film transistor group by evaporation; the second metal electrode is attached to the conversion layer by evaporation.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the invention relates to a flat panel detector, which comprises a thin film transistor group, a first metal electrode, a conversion layer and a second metal electrode, wherein the thin film transistor group, the first metal electrode, the conversion layer and the second metal electrode are sequentially arranged from bottom to top; the thin film transistor group comprises n thin film transistors, wherein n is a positive integer greater than or equal to 1; the source electrode of each thin film transistor is connected with the first metal electrode; the conversion layer is composed of silver nanowires, quantum dots and scintillator colloids. The silver nanowire has high conductivity, can quickly collect and transmit free carriers, reduces working voltage, reduces signal reading time and improves imaging quality.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a front cross-sectional view of a flat panel detector according to the present invention.

Description of the symbols: the method comprises the following steps of 1-a thin film transistor group, 2-a first metal electrode, 3-a second metal electrode, 4-a light reflecting sealing layer, 5-a first layer, 6-a second layer, 7-a third layer, 8-silver nanowires, 9-quantum dots and 10-scintillator colloid.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a flat panel detector, which is used for improving the conductivity of the flat panel detector and improving the imaging quality.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Fig. 1 is a front cross-sectional view of a flat panel detector of the present invention, and as shown in fig. 1, the present invention provides a flat panel detector, which includes a thin film transistor group 1, a first metal electrode 2, a conversion layer and a second metal electrode 3, which are sequentially disposed from bottom to top.

The thin film transistor group 1 comprises n thin film transistors, n is a positive integer larger than or equal to 1, the specific number is selected according to actual requirements, and the specific distribution mode can be divided by a planar rectangular array.

The source electrode of each thin film transistor is connected with the first metal electrode 2.

The conversion layer consists of silver nanowires 8, quantum dots 9 and scintillator colloids 10.

Specifically, the scintillator colloid 10 is any one of cadmium tungstate, cesium iodide, and thallium-doped sodium iodide. In this example, cesium iodide was selected.

The quantum dots 9 are any one of cadmium selenide, silicon, cadmium telluride and indium phosphide. In this embodiment, cadmium selenide is selected.

As an alternative embodiment, the conversion layer of the present invention includes a first layer 5, a second layer 6, and a third layer 7, which are arranged in sequence from bottom to top. The first layer 5 and the third layer 7 are both composed of the silver nanowires 8, the quantum dots 9, and the scintillator colloid 10; the second layer 6 is composed of the quantum dots 9 and the scintillator colloid 10.

Specifically, the thickness of the first layer 5, the second layer 6 and the third layer 7 ranges from 0.01 μm to 100 μm. In this example, 0.05 μm was selected.

Further, assume that the volume of the first layer 5 is set to 1. In the first layer 5, the silver nanowires 8 account for 0.01-0.3 of the total volume of the first layer 5, the quantum dots 9 account for 0.01-0.3 of the total volume of the first layer 5, and the scintillator glue accounts for 0.4-0.98 of the total volume of the first layer 5; the silver nanowires 8, the quantum dots 9 and the scintillator colloid 10 are mixed and solidified according to the above proportion to prepare the first layer 5. In this embodiment, the silver nanowires 8 account for 0.1 of the total volume of the first layer 5, the quantum dots 9 account for 0.1 of the total volume of the first layer 5, and the scintillator glue accounts for 0.8 of the total volume of the first layer 5.

It is assumed that the volume of the third layer 7 is set to 1. In the third layer 7, the silver nanowires 8 account for 0.01-0.3 of the total volume of the third layer 7, the quantum dots 9 account for 0.01-0.3 of the total volume of the third layer 7, and the scintillator glue accounts for 0.4-0.98 of the total volume of the third layer 7; the silver nanowires 8, the quantum dots 9 and the scintillator colloid 10 are mixed and solidified according to the above proportion to prepare the third layer 7. In this embodiment, the silver nanowires 8 account for 0.1 of the total volume of the third layer 7, the quantum dots 9 account for 0.1 of the total volume of the third layer 7, and the scintillator glue accounts for 0.8 of the total volume of the third layer 7.

It is assumed that the volume of the second layer 6 is set to 1. In the second layer 6, the quantum dots 9 account for 0.01-0.3 of the total volume of the second layer 6, and the scintillator colloid 10 accounts for 0.7-0.99 of the total volume of the second layer 6. The quantum dots 9 and the scintillator colloid 10 are mixed and solidified according to the above proportion to prepare the second layer 6. In this embodiment, the quantum dots 9 account for 0.2 of the total volume of the second layer 6, and the scintillator glue accounts for 0.8 of the total volume of the second layer 6.

In order to solve the problem of scattering of visible light generated by the scintillator gel 10, the flat panel detector of the present invention further includes:

and the light reflecting sealing layer 4 is used for performing light reflecting sealing on four side surfaces of the first metal electrode 2, four side surfaces of the conversion layer and four side surfaces of the second metal electrode 3.

Preferably, the first metal electrode 2 is attached to the thin film transistor group 1 by evaporation; the second metal electrode 3 is attached to the third layer 7 by evaporation.

The invention has the following specific beneficial effects:

1) the silver nanowire has high conductivity, and free carriers can be rapidly collected and transmitted.

2) This application is through setting up the reflection of light sealing layer, can effectively reduce the scattering problem of the visible light that the scintillator colloid produced, can also play and keep apart the water and support increase of service life.

3) The method can be suitable for different types of scintillators only by adjusting the diameter of the quantum dots, and the steps of matching optimization are reduced.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The principles and embodiments of the present invention have been described herein using specific examples, which are presented solely to aid in the understanding of the apparatus and its core concepts; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.