CN-116634782-B - Organic direct type X-ray flexible detector based on elastomer and bulk heterojunction blending system and preparation method thereof

CN116634782BCN 116634782 BCN116634782 BCN 116634782BCN-116634782-B

Abstract

The invention provides an organic direct type X-ray flexible detector based on an elastomer and bulk heterojunction blending system and a preparation method thereof, and belongs to the technical field of photoelectric devices. The organic high polymer elastomer material is introduced into the active layer, the balance of high sensitivity and flexibility characteristics of the device is realized by combining the organic high polymer with the bulk heterojunction material, the integral elastic modulus of the active layer of the device is adjustable by introducing the organic high polymer elastomer material, the flexibility characteristics of the device are effectively improved, and the dark current of the device is greatly reduced while the response current of the device is slightly influenced by introducing the organic high polymer elastomer material, so that the electrical performance index represented by sensitivity and signal-to-noise ratio of the device is greatly improved, and the response defect of part of organic heterojunction systems in the field of the X-ray detector is overcome.

Inventors

WU XINGYANG
CHEN HU
ZHANG JIANHUA
LI YI

Assignees

上海大学

Dates

Publication Date: 20260508
Application Date: 20230529

Claims (4)

1. The preparation method of the organic direct type X-ray flexible detector based on the elastomer and bulk heterojunction blending system comprises the following steps: Providing an active layer precursor solution, wherein the composition of the active layer precursor solution comprises a solute and a solvent, and the solute comprises a P-type semiconductor, an N-type semiconductor and an organic high-molecular polymer; ozone and ultraviolet treatment are carried out on the bottom electrode, so that a pretreated bottom electrode is obtained; Coating a hole transport layer material on the surface of the pretreated bottom electrode, and performing first annealing to obtain a hole transport layer; Applying a high-temperature-resistant adhesive tape on the periphery of the surface of the hole transport layer, constructing a physical fence, instilling the precursor solution of the active layer in the physical fence, performing second annealing, removing the high-temperature-resistant adhesive tape after the second annealing, and performing vacuum treatment to obtain the active layer; Sequentially preparing an electron transmission layer and a top electrode on the surface of the active layer to obtain an organic direct type X-ray flexible detector based on an elastomer and bulk heterojunction blending system; The P-type semiconductor comprises one or more of linear condensed ring aromatic hydrocarbon, thiophene oligomer and phthalocyanine compound, and the N-type semiconductor comprises a fullerene material; The organic high molecular polymer comprises one or more of polydimethylsiloxane, polymethyl methacrylate, polyvinyl alcohol and polyvinyl chloride; The mass ratio of the P-type semiconductor to the N-type semiconductor to the organic high polymer is 1:1:0.5-2; the thickness of the active layer is 6-10 mu m; The second annealing comprises a first-stage annealing and a second-stage annealing which are sequentially carried out, wherein the temperature of the first-stage annealing is 60-80 ℃, the heat preservation time is 30-60 min, the temperature of the second-stage annealing is 130-150 ℃ and the time is 10min; The pressure of the vacuum treatment is less than or equal to 3.2 multiplied by 10 -3 bar, and the dwell time is more than or equal to 12 hours; the hole transport layer material is poly (3, 4-ethylenedioxythiophene) -poly (styrenesulfonic acid); the temperature of the first annealing is 140-160 ℃, and the heat preservation time is 10-30 min; The electron transport layer is made of BPC, the top electrode is a silver electrode, and the thickness of the top electrode is 90-100 nm.
2. The preparation method according to claim 1, wherein the solvent is one or more of chloroform, chlorobenzene, dichlorobenzene and toluene; the concentration of solute in the active layer precursor solution is 40-80 mg/mL.
3. The organic direct type X-ray flexible detector based on an elastomer and bulk heterojunction blending system prepared by the preparation method of any one of claims 1-2, which comprises a bottom electrode, a hole transport layer, an active layer, an electron transport layer and a top electrode which are sequentially laminated; The active layer comprises a P-type semiconductor, an N-type semiconductor and an organic high molecular polymer.
4. The organic direct type X-ray flexible detector based on the elastomer and bulk heterojunction blend system according to claim 3, wherein the thickness of the bottom electrode is 80-100 nm; The thickness of the hole transport layer is 150-300 nm; the thickness of the active layer is 6-10 mu m; the thickness of the electron transport layer is 35-50 nm; the thickness of the top electrode is 90-100 nm.

Description

Organic direct type X-ray flexible detector based on elastomer and bulk heterojunction blending system and preparation method thereof Technical Field The invention relates to the technical field of photoelectric devices, in particular to an organic direct type X-ray flexible detector based on an elastomer and bulk heterojunction blending system and a preparation method thereof. Background The working principle of the direct X-ray detector is that the active layer directly converts X-rays passing through an object to be detected into electric signals, then a computer is used for controlling a switch of a capacitor in a thin film transistor pixel array to collect the electric signals, the electric signals are converted into images, and the color depth of pixel points in the images is determined by the intensity of the generated electric signals. Because the X-rays are absorbed by the measured object to different degrees, the X-ray dosage rate passing through the measured object can reflect the shape of the object, and the active layer is used for converting the X-rays with different dosage rates into electric signals with different intensities, and the shape of the object is described by the color depth of the pixel points. The core part of the direct X-ray detector is an active layer film which plays roles in carrier generation and transportation, and is the most important component part of the X-ray detector. Organic materials have considerable application prospects in the field of photoelectric detection, and bulk heterojunction systems formed by combining P-type materials and N-type materials are typical of the materials. However, due to the limitation of the material on the X-ray absorption and attenuation capability, the prepared detector based on the material film has poor photoelectric conversion performance, and the preparation of the active layer with higher thickness is often limited to the application of a rigid detector, so that the detector has poor flexibility. To achieve a high performance organic direct X-ray flexible detector, a combination of high conversion efficiency of the active layer and flexible and reliable fabrication of the device is necessary. The existing organic X-ray detectors in the market are prepared by using rigid films, and the flexibility of the device is poor. And the increase of the thickness of the active layer of the organic material can lead to the increase of dark current (background noise) of the detector, the charge transmission capability of the device is reduced, and the preparation of the high-performance detector is difficult to realize. In summary, the sensitivity and flexibility characteristics of the existing detector cannot be balanced, and the situation that the existing detector is out of phase is unavoidable. Disclosure of Invention In view of the above, the present invention aims to provide an organic direct type X-ray flexible detector based on an elastomer and bulk heterojunction blending system and a preparation method thereof. The organic direct type X-ray flexible detector based on the elastomer and bulk heterojunction blending system provided by the invention realizes the balance of high sensitivity and flexibility characteristics of the device. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a preparation method of an organic direct type X-ray flexible detector based on an elastomer and bulk heterojunction blending system, which comprises the following steps: Providing an active layer precursor solution, wherein the composition of the active layer precursor solution comprises a solute and a solvent, and the solute comprises a P-type semiconductor, an N-type semiconductor and an organic high-molecular polymer; ozone and ultraviolet treatment are carried out on the bottom electrode, so that a pretreated bottom electrode is obtained; Coating a hole transport layer material on the surface of the pretreated bottom electrode, and performing first annealing to obtain a hole transport layer; Applying a high-temperature-resistant adhesive tape on the periphery of the surface of the hole transport layer, constructing a physical fence, instilling the precursor solution of the active layer in the physical fence, performing second annealing, removing the high-temperature-resistant adhesive tape after the second annealing, and performing vacuum treatment to obtain the active layer; And sequentially preparing an electron transmission layer and a top electrode on the surface of the active layer to obtain the organic direct type X-ray flexible detector based on the elastomer and bulk heterojunction blending system. Preferably, the P-type semiconductor comprises one or more of linear condensed aromatic hydrocarbon, thiophene oligomer and phthalocyanine compound, and the N-type semiconductor comprises a fullerene material represented by a C60 derivative. Preferably, the organic high mol