A sulfonated chitosan / poly 3,4-ethylenedioxythiophene material and its preparation method and application

Abstract

The present invention discloses a sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material and its preparation method and application. The present invention obtains the sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material by reacting sulfonated chitosan with 3,4-ethylenedioxythiophene in a polar solvent. The present invention utilizes the selective reaction of chitosan amino groups and C6 hydroxyl groups to achieve precise control of the sulfonic acid substitution position. The reactivity of amino groups and C6 hydroxyl groups is utilized to achieve a sulfonic acid-substituted chitosan with a molar substitution degree close to 2, thereby increasing the proportion of conjugated structural units in chitosan-based PEDOT, improving the energy level of its film, and enhancing the hole transport mobility of its film, thereby solving the problem of low content of conjugated structural units in traditional PEDOT and cellulose-based PEDOT. The performance of optoelectronic devices based on chitosan-based PEDOT is also significantly higher than that of traditional PEDOT and cellulose-based PEDOT devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of hole transport / collection materials for organic optoelectronic devices, and in particular relates to a sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material and a preparation method and application thereof. Background Art

[0002] Organic optoelectronic devices, with their advantages of simple fabrication, compatibility with flexible substrates, and easy tailoring of molecular properties, have recently been widely used in flat-panel displays, photovoltaic cells, chemical sensors, electronic skin, smart wearables, and other fields. Compared to inorganic semiconductor devices, organic optoelectronic devices can be produced over large areas, with high efficiency and continuous production through wet processing. Therefore, the research and development of solution-processable organic conductive materials for efficient hole / electron transport and collection is crucial.

[0003] The research and development of wet-processable hole transport / collection materials, primarily represented by poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS), has been widely used in organic light-emitting diodes (OLEDs), organic solar cells (OSCs), organic field-effect transistors (OTFTs), and perovskite optoelectronic devices (PePEDs). Patents have been filed for related products and applications, such as ZL201310401634.3, ZL201510404590.9, and ZL201510167606.9, which explicitly protect their use as hole transport / collection layer materials in organic optoelectronic devices. However, PEDOT:PSS, used for hole transport / collection in organic optoelectronic devices, generally suffers from low conductivity (<1S / cm). Its introduction inevitably increases the series resistance of the device, hindering the transport and collection of carriers, thereby affecting the device's photoelectric conversion efficiency. Furthermore, PEDOT:PSS has a relatively simple work function and poor energy level adjustability, which cannot meet the device's requirements for multi-energy level matching. Therefore, the modification of PEDOT:PSS remains crucial for the development of high-performance organic optoelectronic devices.

[0004] To improve the conductivity of PEDOT:PSS, a common approach is to introduce a third component as a "secondary dopant" to enhance its conductivity. While this can improve the conductivity of PEDOT:PSS to varying degrees, secondary dopants are ineffective in effectively manipulating its energy levels and work function. In recent years, researchers have proposed that starting from the polymerization of 3,4-ethylenedioxythiophene, by introducing sulfonic acids of varying structures as replacements for polystyrene sulfonic acid, this approach not only improves the conductivity of the resulting films but also effectively manipulates their energy levels. For example, Okuzaki reported that by introducing sulfonic acid groups onto EDOT segments, the resulting PEDOT films exhibited a conductivity as high as 1089 S / cm. Li et al. used water-dispersed aromatic amine sulfonic acids to synthesize PEDOT in situ, demonstrating an order of magnitude increase in film conductivity and significant control over its work function. Recently, patent ZL 202010034186.8 protected a method for preparing and applying a TEMPO-oxidized cellulose / PEDOT polymer, providing a new approach for preparing PEDOT from biomass-based functional materials. However, due to the poor reactivity of TEMPO-oxidized cellulose, the degree of sulfonic acid substitution is very low, which severely affects the conductivity of its films. Chitosan has a structure very similar to cellulose, differing only in the groups attached to the second carbon of the glucose ring. The amino group of chitosan is highly reactive, allowing for a high degree of sulfonic acid substitution, showing great potential as a cellulose alternative to prepare highly conductive PEDOT. However, the synthesis of PEDOT using sulfonated chitosan as a template instead of PSS has not yet been reported. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material and its preparation method and application. The sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material of the present invention is suitable for preparing hole transport / collection materials for optoelectronic devices.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material, the structural formula of which is as follows:

[0008]

[0009] Wherein, R is selected from Preferably, the structural formula of R is as follows:

[0010]

[0011] The preparation method of the sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material comprises the following steps:

[0012]

[0013] In a polar solvent, the compound of formula B is reacted with 3,4-ethylenedioxythiophene to obtain the sulfonated chitosan / poly-3,4-ethylenedioxythiophene material of the compound of formula A.

[0014] Preferably, the reaction is carried out in the presence of a catalyst;

[0015] More preferably, the catalyst is one or more of ammonium persulfate and ferric oxide;

[0016] Preferably, the molar ratio of the basic unit of the compound of formula B to 3,4-ethylenedioxythiophene is 1:1-1:3;

[0017] Preferably, the polar solvent is one or more of dimethylformamide, dimethyl sulfoxide, water, and N-methylpyrrolidone.

[0018] Preferably, the preparation method of the compound of formula B comprises the following steps:

[0019]

[0020] In an inert solvent, reacting a compound of formula C with a compound of formula D to obtain a compound of formula B;

[0021] More preferably, the inert solvent is one or more of methanol, acetonitrile, acetic acid, ethyl acetate, and tetrahydrofuran.

[0022] More preferably, the molecular weight of the compound of formula C is 0.5 KDa-170 KDa.

[0023] A hole transport / collection layer of an optoelectronic device is prepared from the above-mentioned sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material.

[0024] An optoelectronic device comprising:

[0025] (a) substrate;

[0026] (b) a transparent conductive layer covering the substrate;

[0027] (c) a hole transport / collection layer located on the transparent conductive layer; the hole transport / collection layer is the hole transport / collection layer of the above-mentioned optoelectronic device;

[0028] (d) a photoactive layer on the hole transport / collection layer;

[0029] (e) an electron transport / collection layer on the photosensitive layer;

[0030] (f) Electrodes located above the electron transport / collection layer.

[0031] Preferably, the optoelectronic device includes an organic light-emitting diode, an organic solar cell, or a perovskite solar cell.

[0032] Further preferably, the material of the photosensitive layer of the organic electroluminescent diode is poly(9-vinylcarbazole) / tris(2-phenylpyridine)iridium / 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole PVK / IrPPy / PBD, poly(9-vinylcarbazole) / 8-hydroxyquinoline aluminum PVK / Alq3;

[0033] Further preferably, the material of the photosensitive layer of the organic solar cell is poly[2,6-(4,8-bis-(5-(2-ethyl-3-fluorenyl)thienyl)-benzo[1,2-b:4,5-b']dithiophene))-(5,5-(1',3'-di-2-thiophene-5',7'-bis-'(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione]PM6, poly[5-(5-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophene-2-yl)benzo[1,2-b:4,5-b']disulfanyl-2-yl)-4-(2-butyl)thiophene-2-yl]-8 -(4-(2-butylbutyl)thiophen-2-yl)dithieno[3',2':3,4;2",3':5,6]benzo[1,2-c][1,2,5]thiadiazole)] D18, 12,13-di(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-E]thieno[2",3":4',5']thieno[2',3':4,5]pyrrolo[3,2-G]thieno[2',3':4,5]thieno[3,2-B]indole-2,10-bis(5,6-difluoro-3-(dicyanomethylidene)indene-1-one) Y6;

[0034] Further preferably, the material of the photosensitive layer of the perovskite solar cell is MAPBI3, Cs 0.05 MA 0.05 FA 0.9 PbBr x I 1-x ;

[0035] Preferably, the substrate is glass or a flexible transparent film;

[0036] Preferably, the material of the transparent conductive layer is indium-doped tin oxide or silver nanowires;

[0037] Preferably, the material of the electron transport / collection layer is one or more of metallic calcium, metallic magnesium, lithium fluoride, PDIN, NDI, and PDINO.

[0038] Preferably, the thickness of the hole transport / collection layer is 30-50 nm;

[0039] Preferably, the thickness of the photosensitive layer is 90-650 nm;

[0040] Preferably, the thickness of the electron transport / collection layer is 1-30 nm;

[0041] Preferably, the material of the electrode is metal aluminum or silver;

[0042] Preferably, the hole transport / collection layer, the photosensitive layer, and the electron transport / collection layer are all prepared by solution film formation;

[0043] Preferably, an electron buffer layer is provided between the electron transport / collection layer and the electrode.

[0044] Preferably, the method for preparing the optoelectronic device comprises the steps of:

[0045] (1) providing a substrate having a transparent conductive film;

[0046] (2) depositing the hole transport / collection material on the transparent conductive film to form a hole transport / collection layer;

[0047] (3) depositing the photosensitive material on the hole transport / collection layer to form a photosensitive layer;

[0048] (4) depositing the electron transport material on the photosensitive layer to form an electron transport / collection layer;

[0049] (5) Depositing the electrode material on the electron transport / collection layer to form an electrode.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] By utilizing the selective reaction between chitosan amino groups and the C6 hydroxyl group, precise control of the sulfonic acid substitution position is achieved, resolving the uncertainty inherent in traditional cellulose sulfonic acid substitution at the C2 and C3 positions. Furthermore, leveraging the reactivity of amino groups and the C6 hydroxyl group, a sulfonic acid-substituted chitosan with a molar substitution degree close to 2 is achieved. This increases the proportion of conjugated structural units in chitosan-based PEDOT, improves the energy level of the film, and enhances the hole transport mobility of the film, resolving the issue of low conjugated structural unit content found in traditional PEDOT and cellulose-based PEDOT. The performance of optoelectronic devices based on chitosan-based PEDOT is also significantly superior to that of traditional PEDOT and cellulose-based PEDOT devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1Schematic diagram of the structure of the organic optoelectronic device according to Examples 3-5 of the present invention. DETAILED DESCRIPTION

[0053] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. The experimental methods in the following examples, for which specific conditions are not specified, are generally based on conventional conditions or the conditions recommended by the manufacturer. Unless otherwise stated, percentages and fractions are calculated on a molar basis.

[0054] The molecular weight of the chitosan compound used in the examples is 50 kDa.

[0055] Example 1: Synthesis of Compound A-1

[0056] In this embodiment, the structural formula of the compound of formula A-1 is:

[0057]

[0058] The preparation method of the compound of formula A-1 comprises the following steps:

[0059] Step 1: Synthesis of intermediate formula B-1, 3-(N'-ethyldiphenylamino)amide-6-(N'-ethyldiphenylamino)amide chitosan ester

[0060] One part (1 mol, calculated as basic unit; "part" below is 1 mol) of chitosan compound was placed in a 250 ml three-necked flask, protected by argon, and 60 ml of N-methylmorpholine ionic liquid solution was added. The mixture was stirred for 30 minutes, and 2.5 parts of 4-((4-(chlorocarbonyl)phenyl)(ethyl)amino)benzenesulfonic acid were injected into the reaction system. The mixture was heated to 75° C. with stirring and reacted for 5 days. After the reaction, the mixture was dialyzed using 500 and 1000 mesh filter membranes, respectively, and freeze-dried to obtain formula B-1, 3-(N'-ethyldiphenylamino)amide-6-(N'-ethyldiphenylamino)amide chitosan ester with a yield of 85.5%. The structure of the compound was determined by infrared spectroscopy, with a wavelength of 1727 cm -1 、1695cm -1 There are strong carbon-based absorption peaks at 1182 cm-1, which can be identified as the carbon groups on the ester and amide bonds; -1 and 1054cm -1 There are strong absorption peaks at 3300~3210cm -1 Strong absorption peaks appear at 1601 cm -1 、1498cm -1 、1310cm -1The presence of benzene ring absorption indicates that the benzene ring structure from diphenylamine has been incorporated into the target compound. Elemental analysis revealed that the sulfur content in compound B-1 was 8.17%, confirming a molar substitution degree of 1.95 for the target compound. This indicates that the chitosan's hydroxyl group at position 6 and the amino group at position 3 reacted completely with 4-((4-(chlorocarbonyl)phenyl)(ethyl)amino)benzenesulfonic acid in a ratio of 1:2.

[0061] Step 2: Synthesis of Compound A-1

[0062] A 0.1 mol / L aqueous NaOH solution was added dropwise to a 150 mL aqueous solution containing 10 parts (based on unit) of compound B-1, 3-(N'-ethyldiphenylamino)amide-6-(N'-ethyldiphenylamino)amide chitosan ester. The pH was adjusted to neutral (pH = 7) and the mixture was stirred vigorously for approximately 30 minutes. 45 parts of Fe(NO₃)₃·9H₂O were dissolved in 10 mL of water and added dropwise to the mixture. Subsequently, 20 parts of EDOT were added to the mixture and stirred at room temperature. The mixture immediately turned from colorless to dark blue. After 4 hours, it was filtered and vacuum-dried at 50°C to obtain a blue powder, namely diphenylaminosulfonated chitosan / PEDOT powder. Sol-gel chromatography was used to determine the molecular weight distribution of the target compound, which was 24,500 g / mol. Compared to compound B-1, its infrared spectrum showed a peak at 1250 cm -1 The infrared absorption peak of the thiophene group appears, which is the characteristic infrared spectrum of thiophene. At the same time, at 2815cm -1 and 1034cm -1 Strong infrared absorption appeared at the target compound, indicating that an ether bond structure of an aromatic group connected to an alkyl group was introduced into the target compound, indicating that a thiophene ether bond unit was introduced into the target polymer; elemental analysis showed that the sulfur element was increased to 30.56%, confirming that the target compound was diphenylaminosulfonated chitosan / PEDOT.

[0063] Furthermore, in order to meet the application requirements of organic optoelectronic devices, diphenylaminosulfonated chitosan / PEDOT was prepared into an aqueous dispersion with a solid content of 1.0 wt%, labeled as DPASS / PEDOT solution, and used for the preparation of organic optoelectronic devices.

[0064] Example 2: In this example, the structural formula of the compound of formula A-2 is:

[0065]

[0066] The preparation method of the compound of formula A-2 comprises the following steps:

[0067] Step 3: Synthesis of intermediate formula B-2,3-(N'-ethylcarbazolyl)amide-6-(N'-ethylcarbazolyl)amide chitosan ester

[0068] Two parts of chitosan compound were placed in a 250 ml three-necked flask under argon protection. 120 ml of N-methylmorpholine ionic liquid solution was added and stirred for 60 minutes. 5 parts of 6-(chlorocarbonyl)-9-ethyl-9H-carbazole-3-sulfonic acid were injected into the reaction system. The mixture was heated to 70°C with stirring and allowed to react for 7 days. After the reaction, the mixture was dialyzed using 500 and 1000 mesh filter membranes, respectively, and freeze-dried to obtain formula B-2, 3,3-(N'-ethylcarbazolyl)amide-6-(N'-ethylcarbazolyl)amide chitosan ester in an 88.2% yield. The structure of the compound was determined by infrared spectroscopy, with a wavelength of 1733 cm -1 、1691cm -1 There are strong carbon-based absorption peaks at 1191 cm -1 and 1064cm -1 There are strong absorption peaks at 3350-3230cm -1 Strong absorption peaks appear at 1601 cm -1 、1498cm -1 、1310cm -1 The presence of benzene ring absorption indicates that the benzene ring structure of the carbazole unit has been introduced into the target compound. Elemental analysis revealed that the sulfur content of compound B-2 was 8.29%. The reaction efficiency of the target compound was determined to be 1.98, indicating that the chitosan's 6-hydroxyl group and 3-amino group reacted completely with 6-(chlorocarbonyl)-9-ethyl-9H-carbazole-3-sulfonic acid in a ratio of 1:2.

[0069] Step 4: Synthesis of Compound A-2

[0070] A 0.2 mol / L aqueous NaOH solution was added dropwise to a 150 mL aqueous solution containing 5 parts of monomer B-2, 3-(N'-ethylcarbazolyl)amide-6-(N'-ethylcarbazolyl)amide chitosan ester. The pH was adjusted to neutral (pH = 7) and the mixture was stirred vigorously for approximately 15 minutes. 25 parts of Fe(NO₃)₃·9H₂O were dissolved in 5 mL of water and added dropwise to the mixture. Subsequently, 10 parts of EDOT were added to the mixture and stirred at room temperature. The mixture immediately turned from colorless to dark blue. After 2 hours, it was filtered and vacuum-dried at 60°C to obtain a blue powder, namely, carbazolyl sulfonated chitosan / PEDOT powder. Sol-gel chromatography was used to determine the molecular weight distribution of the target compound, which was 26,400 g / mol. Compared to compound B-2, its infrared spectrum showed a peak at 1235 cm -1 The infrared absorption peak of the thiophene group appears, which is the characteristic infrared spectrum of thiophene. At the same time, at 2823cm-1 and 1045cm -1 Strong infrared absorption appeared at the target compound, indicating that an ether bond structure of an aromatic group connected to an alkyl group was introduced into the target compound, indicating that a thiophene ether bond unit was introduced into the target polymer; elemental analysis showed that the sulfur element was increased to 30.94%, confirming that the target compound was carbazole-sulfonated chitosan / PEDOT.

[0071] Furthermore, in order to meet the application requirements of organic optoelectronic devices, carbazole-sulfonated chitosan / PEDOT was prepared into an aqueous dispersion with a solid content of 1.5 wt %, labeled as CzSS / PEDOT solution, for the preparation of organic optoelectronic devices.

[0072] Example 3: Preparation of an organic optoelectronic device based on a hole transport / collection layer of compounds A-1 and A-2—an organic electroluminescent diode

[0073] The sulfonated chitosan / PEDOT hole transport / collection material can be used in organic electroluminescent devices. The organic electroluminescent device has a layered structure, such as Figure 1 As shown in a, the substrate to the electrode is composed of substrate 1, transparent conductive layer 2, hole transport / collection layer 3, photosensitive layer 4, electron transport / collection layer 5, electron buffer layer 6, and electrode 7. Among them, the substrate 1 is made of glass; the transparent conductive layer 2 is made of indium-doped tin oxide with a sheet resistance of 10Ω / sq; after cleaning, the substrate is treated with plasma in an air atmosphere for 15 minutes, and the transparent conductive layer 2 is prepared by magnetron sputtering with a thickness of 150nm. ITO, then, sulfonated chitosan / PEDOT hole transport / collection material is spin-coated in air and annealed (140°C, 20 min) to obtain a hole transport / collection layer 3 with a thickness of 40 nm; then it is transferred into a glove box, and a photosensitive layer 4 (PVK / IrPPy or PVK / Alq) is spin-coated on the hole transport / collection layer 3 with a thickness of 120 nm and annealed (120°C, 30 min). After that, an electron transport / collection layer 5 (TPBi) is evaporated on the photosensitive layer 4 with a thickness of 40 nm, and then an electron buffer layer 6 (LiF) is deposited on the electron transport layer 5 with a thickness of 0.5 nm. Finally, a metal electrode 7 is evaporated on the electron buffer layer 6, and metal aluminum is selected with a thickness of 80 nm.

[0074] During the preparation of the organic electroluminescent device, the thickness of the spin-coated film was measured using a step profiler, and the photoelectric performance of the organic electroluminescent diode was tested using a PR670 spectrophotometer / colorimeter / irradiance meter combined with a Keithley 2400 digital source meter.

[0075] The performance of the above-mentioned electroluminescent device is shown in Table 1.

[0076] Table 1: Performance of organic electroluminescent devices based on the hole transport / collection layer in Examples 1-2

[0077]

[0078] Experimental results show that organic electroluminescent devices prepared by wet processing using PEDOT prepared in situ via chitosan exhibit excellent electroluminescent properties, significantly improving over commercial PEDOT (4083). For carbazole-substituted chitosan-based PEDOT, based on PVK / IrPPy / PBD as the luminescent layer, the turn-on voltage was 3.1V, and the electroluminescent efficiency was 67.9cd / A, 63.1lm / W, and 23.5%, respectively. These performances were significantly superior to those of diphenylamine-substituted chitosan-based PEDOT devices (3.2V, 63.7cd / A, 60.6lm / W, and 24.2%). This is primarily due to the better energy level match between the carbazole-substituted chitosan-based PEDOT and the ITO conductive layer, resulting in a lower hole injection barrier and a more even energy level match. Similar results were observed using PVK / Alq as the luminescent layer.

[0079] Example 4: Preparation of an organic optoelectronic device—an organic solar cell—based on a hole transport / collection layer of compounds A-1 and A-2

[0080] The sulfonated chitosan / PEDOT hole transport / collection material can be used in organic solar cells. The organic solar cell has a layered structure, such as Figure 1 As shown in b, the substrate to the electrode is sequentially composed of a substrate 1, a transparent conductive layer 2, a hole transport / collection layer 3, a photosensitive layer 4, an electron transport / collection layer 5, and an electrode 6. Among them, the substrate 1 is made of glass; the transparent conductive film 2 is made of indium-doped tin oxide with a square resistance of 15Ω / sq; after the substrate is cleaned, it is glow discharged (Plasma) treated in an air atmosphere for 20 minutes, and the transparent conductive layer 2 is prepared by a magnetron sputtering method. 150nm ITO, sulfonated chitosan / PEDOT hole transport / collection material is spin-coated in air, and annealed (150℃, 10min) to obtain a hole transport / collection layer 3 with a thickness of 30nm; then it is transferred to a glove box, and a photosensitive layer 4 (PM6 / Y6 or D8, Y6) is spin-coated on the hole transport / collection layer 3 with a thickness of 95nm, annealed (90℃, 10min), and then a layer of electron transport / collection layer 5 (PDIN) is spin-coated on the photosensitive layer 4 with a thickness of 15nm. Finally, an electrode 6 is deposited on the electron transport / collection layer 5, and metallic silver is selected with a thickness of 100nm.

[0081] During the preparation of the organic solar cell, the thickness of the spin-coated film was measured using a profilometer, and the photoelectric conversion performance of the cell was tested using a Newport solar simulator combined with a Keithley 2400 digital source meter.

[0082] The performance of the above organic solar cell is shown in Table 2.

[0083] Table 2: Performance of organic solar cells based on the hole transport / collection layer in Examples 1-2

[0084]

[0085] According to the experimental results, organic solar cells prepared by wet processing of PEDOT prepared in situ by chitosan also show improved photoelectric performance. Based on carbazole-substituted chitosan-based PEDOT solar cells, using D8 / Y6 as the photosensitive layer, the performance of the cell is: 27.75mA / cm 2 , 0.862V, 75.77%, 18.12%; while the diphenylamine substituted chitosan-based PEDOT device was 27.54mA / cm 2 , 0.862V, 75.75%, and 17.98%; at the same time, it is significantly improved compared to the commercial PEDOT (4083). This is because the energy barrier of the energy level of the carbazole-substituted chitosan-based PEDOT is low, which is conducive to the injection of hole carriers. Similar results were also shown based on PM6 / Y6 as the photosensitive layer.

[0086] Example 5: Preparation of organic optoelectronic devices based on compound A-1 and A-2 hole transport / collection layer - perovskite solar cells

[0087] The above sulfonated chitosan / PEDOT hole transport / collection material can be applied to perovskite solar cells. The perovskite cell has a layered structure. The perovskite solar cell has a layered structure, such as Figure 1 As shown in c, the substrate 1, transparent conductive film 2, hole transport / collection layer 3, photosensitive layer 4, electron transport / collection layer 5, electron buffer layer 6, and electrode 7 are sequentially included from the base to the electrode. Among them, the substrate 1 is made of glass; the transparent conductive film 2 is made of indium-doped tin oxide with a square resistance of 10Ω / sq; after the substrate is cleaned, it is glow-discharged (Plasma) treated in air for 15 minutes, and the transparent conductive layer 2 is prepared by magnetron sputtering 150nm ITO, and sulfonated chitosan / PEDOT hole transport / collection material is spin-coated in air, annealed (140℃, 10min), to obtain a hole transport / collection layer 3 with a thickness of 25nm; then it is transferred to a glove box, and the photosensitive layer 4 (MAPbI3 or Cs 0.05 MA 0.05 FA 0.9 I 1-x Br x), with a thickness of 600 nm, annealed (100 ° C, 20 min), and then a layer of electron transport / collection layer 5 (PC 61 BM) with a thickness of 20nm, and then a 5nm electronic buffer layer 6 (BCP) is spin-coated thereon; finally, an electrode 7 is deposited on the electronic buffer layer 6, and metallic silver is selected with a thickness of 120nm.

[0088] During the preparation process of the above-mentioned perovskite solar cell, the thickness of the spin-coated film was measured using a step profiler, and the photoelectric conversion performance of the cell was tested using a Newport solar simulator combined with a Keithley 2400 digital source meter.

[0089] The performance of the above perovskite solar cells is shown in Table 3.

[0090] Table 3: Performance of perovskite solar cells in Examples 1-2

[0091]

[0092] According to the experimental results, the perovskite solar cells prepared by wet processing of PEDOT prepared in situ by chitosan also showed improved photoelectric performance. 0.05 MA 0.05 FA 0.9 I 1-x Br x As the photosensitive layer, the performance of the battery is: 24.52mA / cm 2 , 1.06V, 79.03%, 20.54%; while the diphenylamine substituted chitosan-based PEDOT device was 24.35mA / cm 2 , 1.05V, 78.72%, and 20.13%; at the same time, it is significantly improved compared to commercial PEDOT (4083). This is because the energy barrier of the energy level of the carbazole-substituted chitosan-based PEDOT is low, which is conducive to the injection of hole carriers. Similar results were also shown based on MAPbI3 as the photosensitive layer.

[0093] The above-described embodiments provide a detailed description of the technical solutions of the present invention. The preparation methods of the other derivatives involved in the present invention are similar to those of the corresponding embodiments, with only the corresponding substitution structures being modified. It should be understood that the preparation methods described above are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements, or similar substitutions made within the scope of the principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material, characterized in that: The structural formula is as follows: Wherein, R is selected from and .

2. The sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material according to claim 1, characterized in that: The structural formula of R is as follows: 。 3. The method for preparing the sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material according to any one of claims 1 to 2, characterized in that: The following steps are involved: In a polar solvent, the compound of formula B is reacted with 3,4-ethylenedioxythiophene to obtain the sulfonated chitosan / poly-3,4-ethylenedioxythiophene material of the compound of formula A.

4. The preparation method according to claim 3, characterized in that The reaction is carried out in the presence of a catalyst; the catalyst is one or more of ammonium persulfate and ferric oxide; The molar ratio of the basic unit of the compound of formula B to 3,4-ethylenedioxythiophene is 1:1-1:3; The polar solvent is one or more of dimethylformamide, dimethyl sulfoxide, water and N-methylpyrrolidone.

5. The preparation method according to claim 3, characterized in that The preparation method of the compound of formula B comprises the following steps: In an inert solvent, reacting a compound of formula C with a compound of formula D to obtain a compound of formula B; The inert solvent is one or more of methanol, acetonitrile, acetic acid, ethyl acetate, and tetrahydrofuran; The molecular weight of the compound of formula C is 0.5 KDa-170 KDa.

6. A hole transport / collection layer of an optoelectronic device, characterized in that: The invention is prepared from the sulfonated chitosan / poly (3,4-ethylenedioxythiophene) material according to any one of claims 1 to 2.

7. An optoelectronic device, characterized in that: include: (a) substrate; (b) a transparent conductive layer covering the substrate; (c) a hole transport / collection layer located on the transparent conductive layer; the hole transport / collection layer is the hole transport / collection layer of the optoelectronic device according to claim 6; (d) A photoactive layer located on the hole transport / collection layer; (e) an electron transport / collection layer located on the photoactive layer; (f) Electrodes located above the electron transport / collection layer.

8. The optoelectronic device according to claim 7, wherein: The optoelectronic devices include organic electroluminescent diodes, organic solar cells, and perovskite solar cells.

9. The optoelectronic device according to claim 8, wherein The material of the photosensitive layer of the organic electroluminescent diode is poly (9-vinyl carbazole) / tris (2-phenylpyridine) iridium / 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole PVK / IrPPy / PBD, poly (9-vinyl carbazole) / 8-hydroxyquinoline aluminum PVK / Alq3; The material of the photosensitive layer of the organic solar cell is poly[2,6-(4,8-bis-(5-(2-ethyl-3-fluorenyl)thienyl)-benzo[1,2-b:4,5-b']dithiophene))-(5,5-(1',3'-di-2-thiophene-5',7'-bis-'(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione]PM6, Poly[5-(5-(4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)benzo[1,2-b:4,5-b']disulfanyl-2-yl)-4-(2-butyl)thiophen-2-yl]-8-(4-(2-butylbutyl)thiophen-2-yl)dithieno[3',2':3,4;2'',3':5,6]benzo[1,2-c][1,2,5]thiadiazole) ]D18, 12,13-di(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-E]thieno[2'',3'':4',5']thieno[2',3':4,5]pyrrolo[3,2-G]thieno[2',3':4,5]thieno[3,2-B]indole-2,10-bis(5,6-difluoro-3-(dicyanomethylidene)indene-1-one) Y6; The material of the photosensitive layer of the perovskite solar cell is MAPBI3, Cs 0.05 MA 0.05 FA 0.9 PbBr x I 1-x .

10. The optoelectronic device according to claim 7, wherein The substrate is glass or a flexible transparent film; The transparent conductive layer is made of indium-doped tin oxide and silver nanowires; The material of the electron transport / collection layer is one or more of metallic calcium, metallic magnesium, lithium fluoride, PDIN, NDI, and PDINO; The thickness of the hole transport / collection layer is 30-50 nm; The thickness of the photosensitive layer is 90-650 nm; The thickness of the electron transport / collection layer is 1-30 nm; The materials of the electrodes are metal aluminum and silver; The hole transport / collection layer, photosensitive layer, and electron transport / collection layer are all prepared by solution film formation; An electron buffer layer is provided between the electron transport / collection layer and the electrode.

Images