Application of a multi-dynamic hydrogen bond polymer, perovskite light absorption layer and flexible perovskite solar cell

Abstract

The present invention relates to the application of a multi-dynamic hydrogen bond polymer, a perovskite light absorption layer and a flexible perovskite solar cell, and belongs to the technical field of perovskite solar cells. Dopamine is grafted into polyacrylic acid (PAA-DA) to construct a multi-dynamic hydrogen bond (MDHB) network. The polymer is added to the perovskite light absorption layer as a dopant and then used in a flexible perovskite solar cell. The long chain of PAA in the polymer reduces the mismatch of the thermal expansion coefficient between the perovskite light absorption layer and the substrate through its flexibility and space occupancy, thereby alleviating the interface stress caused by temperature changes. The DA side chain provides multiple dynamic hydrogen bond sites, which significantly reduces the Young's modulus of the perovskite light absorption layer, and helps to increase the energy dissipation of the flexible device during stress deformation. The MDHB network promotes the complete conversion of perovskite at the top and buried interfaces, passivates defects, and inhibits non-radiative recombination inside the solar device.

Description

Technical Field

[0001] The present invention relates to an application of a multi-dynamic hydrogen bond polymer, a perovskite light absorption layer and a flexible perovskite solar cell, and belongs to the technical field of perovskite solar cells. Background Art

[0002] Flexible perovskite solar cells (f-PSCs) have attracted considerable attention as an emerging photovoltaic technology due to their lightweight, low cost, compatibility with curved surfaces, and roll-to-roll mass production. Considering practical applications, mechanical stability remains a significant concern when subjected to continuous or reciprocating external stresses throughout the device's lifetime, becoming a crucial evaluation metric for the commercialization of this novel photovoltaic technology.

[0003] In order to improve the mechanical stability of flexible perovskite solar cells, most of the existing technical solutions are dedicated to regulating the Young's modulus of perovskite. At present, the mechanical stability of flexible perovskite layers is mainly regulated by the following measures: (1) Determine the mechanical fracture point of the polycrystalline perovskite film and add a protective layer during the preparation process to adjust the stress distribution. The thickness of the protective layer is calculated based on the Young's modulus and the thickness of each layer. Finally, the neutral plane (stress value 0) axis is manipulated into the perovskite layer to reduce the total strain and enhance the bending resistance of f-PSCs. (2) Design a biomimetic interface layer. Inspired by the structure of the vertebra, a "cartilage" layer is added to improve the adhesion while releasing the stress during bending, ultimately reducing the Young's modulus from 258MPa to 139MPa to improve the flexibility of the solar cell (Reference: Bio-inspired vertebral design for scalable and flexible perovskite solar cells). (3) In situ cross-linking of polymers to fill the grain boundaries. Releasing stress in the perovskite can also repair grain boundary cracks, enhancing the bending resistance of f-PSCs. Ultimately, the Young's modulus of the film drops dramatically from 41.2 GPa to 32.5 GPa, improving the film's stretchability and deformation capacity (reference: In situcrosslinking-assisted perovskite grain growth for mechanically robust flexible perovskite solar cells with 23.4% efficiency).

[0004] In addition to tuning the Young's modulus of the perovskite absorber layer, the mismatch in thermal expansion coefficients between layers must also be considered for the mechanical stability of the entire flexible device. For solar cell components operating under day and night cycles in outdoor environments, this inherent source of instability will ultimately lead to delamination during mechanical bending, ultimately causing catastrophic device failure. Therefore, the Young's modulus of the perovskite and the thermal expansion coefficient mismatch between the perovskite and substrate jointly determine the mechanical robustness of f-PSCs, but a comprehensive technical strategy for simultaneously manipulating these two parameters has yet to be revealed. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide an application of a multi-dynamic hydrogen bond polymer, a perovskite light absorption layer and a flexible perovskite solar cell.

[0006] To achieve the above objectives, the technical solutions of the present invention are as follows.

[0007] An application of a multi-dynamic hydrogen bond polymer, wherein the polymer is dopamine grafted polyacrylic acid (PAA-DA), and the structural formula is: Wherein, m:n=1:1-2:1, the viscosity-average molecular weight of the polymer is greater than 2500; and the polymer is used as a dopant for a perovskite light absorption layer.

[0008] Preferably, the viscosity-average molecular weight of the polymer is 2,500 to 500,000.

[0009] A perovskite light absorption layer comprises a multi-dynamic hydrogen-bonded polymer and a perovskite material, wherein the multi-dynamic hydrogen-bonded polymer is dopamine-grafted polyacrylic acid (PAA-DA).

[0010] Preferably, the perovskite material is an ABX3 type compound, wherein the A-position cation is CH3NH3 + 、NH2-CH=NH2 + 、Cs + 、Li + 、C4H9NH3 + 、CH6N3 + 、Na + , Rb + and K + More than one of the following: B is Pb 2+ 、Sn 2+ and Ge 2+ More than one of: X is Cl - Br - , I - 、Ac - 、F - 、SCN - and BF4 - More than one of the following.

[0011] A method for preparing a perovskite light absorbing layer according to the present invention comprises the following steps:

[0012] Under a protective gas atmosphere, polyacrylic acid (PAA) was dissolved in an organic solvent, 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) were added, and the reaction was continued for 0.5 to 1 hour. Then, dopamine (DA) was added and the reaction was continued for more than 4 hours to obtain a PAA-DA solution. The molar ratio of polyacrylic acid (PAA) to dopamine (DA) was 1:1 to 2:1. The viscosity-average molecular weight of polyacrylic acid (PAA) was 2000.

[0013] adding a PAA-DA solution to a precursor solution of a perovskite material to obtain a perovskite precursor solution containing PAA-DA; wherein the concentration of PAA-DA in the perovskite precursor solution containing PAA-DA is 0.1 to 1.5 mg / mL;

[0014] A perovskite precursor solution containing PAA-DA is coated on the surface of a conductive substrate, and after annealing, a perovskite light absorption layer is obtained.

[0015] Preferably, the viscosity-average molecular weight of the polyacrylic acid (PAA) is 2,000 to 450,000.

[0016] Preferably, the mass ratio of EDC to NHS is 3 to 6:2, and the total mass of EDC and NHS is 1% to 2% of the mass of PAA.

[0017] Preferably, the organic solvent is a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), and the volume ratio of DMF to DMSO is 4:1 to 9:1.

[0018] Preferably, the concentration of PAA in the organic solvent is 2.5-5 mg / mL.

[0019] Preferably, the concentration of PAA-DA in the perovskite precursor solution containing PAA-DA is 0.2-1 mg / mL.

[0020] A flexible perovskite solar cell comprises the perovskite light absorption layer described in the present invention, with a thickness of 400 to 1000 nm.

[0021] Preferably, the flexible perovskite solar cell comprises a flexible transparent conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a barrier layer and a metal electrode layer, which are arranged in sequence from bottom to top.

[0022] Preferably, the flexible transparent conductive substrate is polyethylene naphthalate (PEN) or polyethylene terephthalate (PET).

[0023] Preferably, the hole transport layer is [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), 2,2',7,7'-tetrakis(N,N-p-methoxyanilino)-9,9'-spirobifluorene (Spiro-MeOTAD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), poly-3-hexylthiophene (P3HT), cuprous thiocyanate (CuSCN), nickel oxide (NiO) or cuprous iodide (CuI), and the thickness of the hole transport layer is 20 to 100 nm.

[0024] Preferably, the electron transport layer is C 60 and its derivatives, zinc oxide (ZnO), tin oxide (SnOx) or fullerene derivatives (PCBM), the thickness of the electron transport layer is 20 to 100 nm.

[0025] Preferably, the barrier layer is 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP) or tin oxide (SnOx), and the thickness of the barrier layer is 6 to 10 nm.

[0026] Preferably, the metal electrode layer is a carbon electrode, gold, copper, silver, aluminum, chromium or an alloy containing the above metals, and the thickness of the electrode layer is 80 to 500 nm.

[0027] Beneficial effects

[0028] The present invention provides an application of a multi-dynamic hydrogen-bonded polymer. Dopamine is grafted onto polyacrylic acid (PAA-DA) to construct a multi-dynamic hydrogen-bonding (MDHB) network. This polymer is added as a dopant to a perovskite light-absorbing layer and is then used in flexible perovskite solar cells. The long PAA chains in this polymer, through their flexibility and spatial occupancy, reduce the coefficient of thermal expansion (CTE) mismatch between the perovskite light-absorbing layer and the substrate, thereby alleviating interfacial stress caused by temperature changes. The DA side chains provide multiple dynamic hydrogen-bonding sites, significantly reducing the Young's modulus of the perovskite light-absorbing layer and helping to increase the energy dissipation of flexible devices during stress deformation. The MDHB network promotes the complete conversion of perovskite at the top and buried interfaces, passivates defects, and inhibits non-radiative recombination within the solar device.

[0029] The present invention provides a perovskite light-absorbing layer. PAA and DA are reacted via an amide reaction to synthesize a PAA-DA polymer, which is then added to a precursor solution. The addition of the polymer effectively improves the crystallization quality of the perovskite film and reduces the bulk defect density of the perovskite layer. Furthermore, due to the poor conductivity of the polymer, the amount of the additive should be carefully controlled. Too low a content will fail to achieve the desired effect, while too high a content will restrict the transport of charge carriers within the device, hindering the improvement of the device's photoelectric conversion efficiency.

[0030] The present invention provides a flexible perovskite solar cell. The device having a PAA-DA-doped perovskite light absorption layer has good stability and bending resistance, and can be widely used to improve the photoelectric conversion efficiency and battery life of flexible photovoltaic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 For PAA and DA and PAA-DA 1 H NMR spectrum.

[0032] Figure 2 Graph showing the change in thermal expansion coefficient for Example 3 and the comparative example.

[0033] Figure 3 Graph showing changes in Young's modulus between Example 3 and the comparative example.

[0034] Figure 4 Statistical distribution diagram of the efficiency of PAA-DA-doped perovskite devices in Example 1, Example 2, Example 3, Example 4, and Example 5.

[0035] Figure 5 JV characteristic curves of the flexible perovskite solar cell devices of Example 3 and the control example.

[0036] Figure 6 Statistical diagram showing the change in photoelectric conversion efficiency of the devices of Example 3 and the control example with the number of bends when the bending radius is 4 mm.

[0037] Figure 7 The scanning electron microscope (SEM) morphology images of the perovskite films obtained in Example 3 and the comparative example are shown. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to specific embodiments.

[0039] A method for preparing a flexible perovskite solar cell, the method comprising the following steps:

[0040] Step 1: In a nitrogen glove box at room temperature, polyacrylic acid (PAA) and dopamine (DA) were mixed and dissolved in an organic solvent, EDC and NHS were added to fully activate the -COOH groups, and then the above solution was doped into the perovskite precursor solution;

[0041] Step 2: attaching the flexible transparent conductive substrate to the rigid glass, treating it with ultraviolet-ozone radiation (UVO), and then transferring it to a nitrogen glove box;

[0042] Step 3: spin-coating a hole transport layer solution on a transparent conductive substrate and performing an annealing treatment;

[0043] Step 4: further spin-coating a perovskite precursor solution doped with a polymer additive on the substrate containing the hole transport layer, and annealing to obtain a perovskite light absorption layer;

[0044] Step 4: Vapor-depositing an electron transport layer on the perovskite light absorption layer under high vacuum conditions;

[0045] Step 5: Vapor-depositing a barrier layer on the electron transport layer under high vacuum conditions;

[0046] Step 6: Under high vacuum conditions, evaporate a metal layer on the barrier layer to prepare a flexible perovskite solar cell.

[0047] Experimental Example 1

[0048] Step 1: Under a nitrogen atmosphere, dissolve 12.5 mg of PAA (viscosity-average molecular weight 450,000) in 2.5 mL of a DMF / DMSO mixture (4:1 volume ratio) and stir thoroughly for 1 hour to disperse the powder. Then, add 3 mg of 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC) and 2 mg of N-hydroxysuccinimide (NHS) to the stirred solution and stir for an additional 0.5 hour to fully activate the -COOH groups. Finally, add 6.5 mg of DA and stir overnight to obtain the PAA-DA dopant solution.

[0049] Step 2: Cut 1.5*1.5cm 2 The flexible transparent conductive substrate was attached to the rigid glass, treated with UVO for 30 min, and then transferred to a nitrogen glove box.

[0050] Step 3: Prepare a 0.3 mg / mL [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz) / anhydrous ethanol solution, spin-coat at 3000 rpm for 30 seconds, and anneal at 100°C for 5 minutes to obtain a hole transport layer.

[0051] Step 4: Prepare 1.65M (Cs 0.15 FA 0.85 )Pb(I0.95 Br 0.05 )3 perovskite precursor solution, use a DMF / DMSO mixed solution with a volume ratio of 4:1, add 20 microliters of the PAA-DA dopant solution prepared in step 1 per milliliter, stir for 2 hours, and filter with a 0.22 micron PTFE filter to obtain a 0.1 mg / mL PAA-DA doped precursor solution. The above perovskite precursor solution is added dropwise on the surface of the substrate coated with the hole transport layer, with a spin coating speed of 6000 rpm and a spin coating time of 30 seconds. 200 microliters of chlorobenzene are added dropwise when 8 seconds are remaining. After spin coating, anneal at 100°C for 30 minutes to obtain a perovskite light absorption layer.

[0052] Step 5: Transfer the sample substrate obtained in step 4 to a high vacuum evaporator, and sequentially evaporate 25nm C60, 8nm BCP and 120nm Ag electrodes to finally obtain a flexible perovskite solar device.

[0053] Experimental Example 2

[0054] The same preparation process as in Experimental Example 1 was used, except that in step 4, 40 μL of the prepared PAA-DA dopant solution was added dropwise per mL. After stirring for 2 h, the solution was filtered through a 0.22 μm PTFE filter to obtain a 0.2 mg / mL PAA-DA-doped precursor solution. All other conditions remained the same.

[0055] Experimental Example 3

[0056] The same preparation process as in Experimental Example 1 was used, except that in step 4, 100 μL of the prepared PAA-DA dopant solution was added dropwise per mL. After stirring for 2 h, the solution was filtered through a 0.22 μm PTFE filter to obtain a 0.5 mg / mL PAA-DA-doped precursor solution. All other conditions remained the same.

[0057] Experimental Example 4

[0058] The same preparation process as in Experimental Example 1 was used, except that in step 4, 200 μL of the prepared PAA-DA dopant solution was added dropwise per mL. After stirring for 2 h, the solution was filtered through a 0.22 μm PTFE filter to obtain a 1.0 mg / mL PAA-DA-doped precursor solution. All other conditions remained the same.

[0059] Experimental Example 5

[0060] The same preparation process as in Experimental Example 1 was used, except that in step 4, 300 μL of the prepared PAA-DA dopant solution was added dropwise per mL. After stirring for 2 h, the solution was filtered through a 0.22 μm PTFE filter to obtain a 1.5 mg / mL PAA-DA-doped precursor solution. All other conditions remained the same.

[0061] Experimental Example 6

[0062] The same preparation process as in Experimental Example 3 was used, except that in step 1, the viscosity-average molecular weight of PAA was 2000. Other conditions remained the same.

[0063] Comparative Example 1

[0064] Step 1: Cut 1.5*1.5cm 2 The flexible transparent conductive substrate was attached to the rigid glass, treated with UVO for 30 min, and then transferred to a nitrogen glove box.

[0065] Step 2: Prepare a 0.3 mg / mL 2PACz / anhydrous ethanol solution, spin-coat at 3000 rpm for 30 seconds, and anneal at 100°C for 5 minutes to obtain a hole transport layer.

[0066] Step 3: Prepare 1.65M (Cs 0.15 FA 0.85 )Pb(I 0.95 Br 0.05 )3 perovskite precursor solution, use a DMF / DMSO mixed solution with a volume ratio of 4:1 to dissolve the drug powder, stir at room temperature for 2 hours, and filter with a 0.22 micron PTFE filter to obtain a precursor solution. The above perovskite precursor solution is dropped onto the surface of the substrate coated with the hole transport layer, with a spin coating speed of 6000 rpm and a spin coating time of 30 seconds. 200 microliters of chlorobenzene is added dropwise when 8 seconds remain. After spin coating, anneal at 100°C for 30 minutes to obtain the perovskite light absorption layer.

[0067] Step 4: Transfer the sample substrate obtained in step 4 to a high vacuum evaporator, and sequentially evaporate 25nm C60, 8nm BCP and 120nm Ag electrodes to finally obtain a flexible perovskite solar device.

[0068] Performance testing:

[0069] (1) Nuclear magnetic resonance spectroscopy ( 1 H NMR): testing equipment: Bruker Avance III (400 MHz); testing conditions: the testing solvent was deuterated DMSO (d6-DMSO).

[0070] Test results: Figure 1 in 1 H NMR was used to characterize the bonding between PAA and DA. The shift in peak position at 8.0 ppm indicates that the hydrogen atoms surrounding the nitrogen atom are affected by the reduced effective magnetic field, resulting in a lower resonance frequency and a reduced chemical shift. This phenomenon confirms the occurrence of a lactamization reaction in the system and the synthesis of the target product.

[0071] (2) X-ray diffraction (XRD): Testing equipment: Bruker D8-DISCOVER X-ray diffractometer; Testing conditions: The sample was placed in a chamber and gradually heated from 50°C to 110°C at intervals of 20°C. During the measurement, thermal equilibrium was achieved by maintaining the sample at each temperature for more than 30 min.

[0072] Test results: Figure 2 The in-situ temperature-dependent XRD characterization results for the perovskite films of Experimental Example 3 and Comparative Example 1 are shown. Within the studied temperature range, the perovskite remains in the cubic phase and does not undergo phase transitions. Increasing temperature causes thermal expansion of the lattice of both samples, resulting in a shift in the diffraction angle toward a lower 2θ degree. PAA-DA-doped Experimental Example 3 exhibits a smaller range of motion than the Comparative Example 1 sample, indicating less thermal expansion. This reduces the thermal expansion coefficient mismatch between the perovskite and substrate, thereby alleviating the interfacial stress caused by temperature changes.

[0073] (3) Quantitative nanomechanical atomic force microscopy (QNM-AFM): Test equipment: Cypher S / Oxford Instruments Asylum Research; Test conditions: Room temperature, thin film samples.

[0074] Test results: Figure 3 To characterize the statistical value of the Young's modulus of perovskite films using QNM-AFM, the use of PAA-DA significantly reduced the average value of the film, thereby increasing the energy dissipation of flexible devices during stress deformation.

[0075] (4) Solar simulator: Under test equipment, solar simulator (Newport) and Keithley 2400 source meter. Test conditions: 25℃, RH 30% environment, AM 1.5G standard irradiance (1000W / m 2 )strength.

[0076] Test results: Figure 4 The solar simulator is used to analyze the photoelectric conversion efficiency of the samples prepared in Experimental Examples 1-5. Figure 5 This is the JV curve of the champion device in Experimental Example 3 and the comparative example. The addition of PAA-DA passivates the defects of the light absorption layer inside the device, further improving the efficiency of the flexible photovoltaic device.

[0077] (5) Flexible bending test: Test equipment: PR-PMC-01 model from Shenzhen Purui Material Technology Co., Ltd.; Test conditions: Nitrogen environment, 25°C, RH 10%, solar cell device.

[0078] Test results: Figure 6Figure 3 shows the mechanical stability of the device after repeated bending at a fixed radius of 4 mm. After 5000 bending cycles at a radius of 4 mm, the f-PSC in Experimental Example 3 retained 90.2% of its original PCE, while that in Comparative Example 1 remained at only 42.1%. The addition of PAA-DA improves the device's mechanical stability.

[0079] (6) Scanning electron microscopy (SEM): Testing equipment: Zeiss Gemini SEM 300; Testing conditions: under vacuum, room temperature, thin film samples.

[0080] Test results: Figure 7 Figure 3 shows the morphology of the perovskite film characterized by SEM. Compared to the comparative example, the film of Experimental Example 3 exhibits a more uniform and dense morphology, with negligible residual PbI2 crystals (e.g., white particles). In contrast, the incorporation of PAA-DA in Experimental Example 3 completely mitigates the formation of PbI2 at the interface. This indicates that the presence of PAA-DA promotes the complete conversion of PbI2 to perovskite.

[0081] The results of Experimental Example 6 are similar to those of Experimental Example 3.

[0082] In summary, PAA-DA is an excellent perovskite precursor dopant that can be used to improve the mechanical stability and photoelectric conversion efficiency of flexible devices. It can be extended to other flexible systems and achieve expected results.

[0083] In summary, the invention includes but is not limited to the above embodiments. Any equivalent replacement or partial improvement made under the spirit and principle of the present invention shall be deemed to be within the scope of protection of the present invention.

Claims

1. An application of a multi-dynamic hydrogen bond polymer, characterized in that: The polymer is dopamine grafted polyacrylic acid, and its structural formula is: , wherein m:n=1:1~2:1, and the viscosity-average molecular weight of the polymer is greater than 2500; the polymer is used as a dopant for the perovskite light absorption layer.

2. The use of a multi-dynamic hydrogen bond polymer according to claim 1, characterized in that: The viscosity average molecular weight of the polymer is 2500-500000.

3. A perovskite light absorbing layer, characterized in that: The invention comprises a multi-dynamic hydrogen-bonding polymer and a perovskite material, wherein the multi-dynamic hydrogen-bonding polymer is the dopamine-grafted polyacrylic acid as claimed in claim 1 or 2.

4. The perovskite light absorbing layer according to claim 3, wherein: The perovskite material is an ABX3 type compound, wherein the A-position cation is CH3NH3 + 、NH2-CH=NH2 + 、Cs + 、Li + 、C4H9NH3 + 、CH6N3 + 、Na + , Rb + and K + More than one of the following: B is Pb 2+ 、Sn 2+ and Ge 2+ More than one of: X is Cl - Br - , I - 、Ac - 、F - 、SCN - and BF4 - More than one of the following.

5. A method for preparing a perovskite light absorbing layer according to claim 3 or 4, characterized in that: The method steps include: Under a protective gas atmosphere, PAA was dissolved in an organic solvent, EDC and NHS were added, and the reaction was continued for 0.5-1 h. DA was then added and the reaction was continued for more than 4 h to obtain a PAA-DA solution; the molar ratio of PAA to DA was 1:1-2:1; adding a PAA-DA solution to a precursor solution of a perovskite material to obtain a perovskite precursor solution containing PAA-DA; wherein the concentration of PAA-DA in the perovskite precursor solution containing PAA-DA is 0.1-1.5 mg / mL; A perovskite precursor solution containing PAA-DA is coated on the surface of a conductive substrate, and after annealing, a perovskite light absorption layer is obtained.

6. The method for preparing a perovskite light absorbing layer according to claim 5, wherein: The viscosity average molecular weight of the PAA is 2000-45000; The mass ratio of EDC to NHS is 3–6:2, and the total mass of EDC and NHS is 1%–2% of the mass of PAA; The organic solvent is a mixed solution of DMF and DMSO, and the volume ratio of DMF to DMSO is 4:1 to 9:1; The concentration of PAA in organic solvent is 2.5~5 mg / mL.

7. The method for preparing a perovskite light absorbing layer according to claim 5, wherein: The concentration of PAA-DA in the perovskite precursor solution containing PAA-DA is 0.2~1 mg / mL.

8. A flexible perovskite solar cell, characterized in that: The perovskite light absorption layer comprises the perovskite light absorption layer according to claim 3 or 4, with a thickness of 400-1000 nm.

9. The flexible perovskite solar cell according to claim 8, characterized in that: The flexible perovskite solar cell includes a flexible transparent conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a barrier layer and a metal electrode layer which are arranged in sequence from bottom to top.

10. The flexible perovskite solar cell according to claim 9, characterized in that: The flexible transparent conductive substrate is polyethylene naphthalate or polyethylene terephthalate; The hole transport layer is [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, 2,2',7,7'-tetrakis(N,N-p-anisyl)-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), poly-3-hexylthiophene, cuprous thiocyanate, nickel oxide or cuprous iodide, and the thickness of the hole transport layer is 20-100 nm; The electron transport layer is C 60 and its derivatives, zinc oxide or tin oxide, wherein the thickness of the electron transport layer is 20 to 100 nm; The barrier layer is 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline or tin oxide, and the thickness of the barrier layer is 6-10 nm; The metal electrode layer is a carbon electrode, gold, copper, silver, aluminum, chromium or an alloy containing the above metals, and the thickness of the electrode layer is 80-500 nm.

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