A method for improving the defects of perovskite quantum dots by irradiation
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANGZHOU UNIV
- Filing Date
- 2026-03-02
- Publication Date
- 2026-06-23
AI Technical Summary
Existing technologies are insufficient to effectively improve the irradiation defects of perovskite quantum dots in aerospace environments, leading to a decline in solar cell performance and an inability to meet the stability requirements for long-term on-orbit operation.
By employing low-energy electron, low-energy proton, and low-flux gamma-ray irradiation methods, the crystal structure and electronic state characteristics of perovskite quantum dots are precisely matched. The quantum dots are then processed using vacuum irradiation equipment and gamma-ray irradiation devices to avoid introducing new defects and to simulate the on-orbit working conditions of spacecraft.
It significantly improves the irradiation stability and photoelectric conversion efficiency of perovskite quantum dots, is suitable for aerospace applications, is easy to operate and can be mass-produced, and is suitable for the preparation of aerospace perovskite solar cells.
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Figure CN122254776A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of performance optimization technology for perovskite quantum dot materials for space environments, specifically relating to an irradiation method for improving defects in perovskite quantum dots and the resulting glass and perovskite quantum dot solar cells. Background Technology
[0002] In the aerospace field, spacecraft energy supply is highly dependent on solar cells, and their performance stability directly determines the spacecraft's on-orbit lifespan and mission efficiency. Perovskite quantum dots, as a novel optoelectronic functional material, demonstrate enormous application potential in aerospace solar cells due to their excellent light absorption coefficient, tunable bandgap, high carrier mobility, and low-cost solution-based fabrication. Compared to traditional photovoltaic materials, perovskite quantum dot solar cells can achieve higher theoretical conversion efficiencies and can be fabricated on flexible substrates for lightweight design, meeting the spacecraft's requirements for miniaturized and integrated energy systems. They are considered one of the core candidate materials for next-generation aerospace solar cells.
[0003] However, the aerospace environment contains a large number of high-energy particles (such as protons, electrons, gamma rays, etc.). When these high-energy particles accumulate to a high dose (usually an irradiation dose exceeding 360 krad), they will severely damage the crystal structure and electronic states of perovskite quantum dots, inducing a series of irradiation defects: on the one hand, high-energy particle bombardment will cause vacancies and interstitial atomic point defects in the perovskite quantum dot lattice, destroying its ordered crystal structure and leading to an accelerated carrier recombination rate; on the other hand, photogenerated carriers generated during irradiation are prone to combine with defect states to form non-radiative recombination centers, significantly reducing carrier separation and transport efficiency, ultimately leading to the decay of the open-circuit voltage (Voc), the decrease in short-circuit current (Jsc), and the reduction in the fill factor (FF) of the solar cell, seriously affecting the on-orbit stability and lifespan of the cell.
[0004] Currently, methods to improve irradiation defects in perovskite quantum dots mainly focus on material modification and device structure optimization. However, most of these methods are implemented during the ground-based fabrication stage. Furthermore, some modification methods introduce new interface defects or reduce the photoelectric activity of the material, making it difficult to achieve a balance between radiation resistance and photoelectric conversion efficiency. For example, while cesium ion (Cs⁺) doping can improve the thermal stability of perovskite quantum dots, it increases the band gap, leading to a narrower light absorption range and a 5%-8% decrease in photoelectric conversion efficiency. Surface coating with silicon dioxide (SiO₂) can reduce direct bombardment by irradiated particles, but when the coating thickness exceeds 5 nm, carrier mobility decreases by more than 20%. In addition, existing irradiation hardening technologies are mostly developed for traditional photovoltaic materials and do not fully consider the unique crystal structure and electron transport characteristics of perovskite quantum dots, resulting in limited hardening effects and failing to meet the requirements for long-term stable on-orbit operation of aerospace solar cells. Therefore, developing an irradiation method that can specifically improve the irradiation defects of perovskite quantum dots and is suitable for aerospace applications has become a key technological bottleneck in promoting the large-scale application of perovskite quantum dot solar cells in the aerospace field. Summary of the Invention
[0005] To address the aforementioned problems, this invention provides an irradiation method for improving defects in perovskite quantum dots and the resulting glass and perovskite quantum dot solar cells.
[0006] The irradiation method for improving defects in perovskite quantum dots according to the present invention includes the following steps: S1. Select glass embedded with ABX3 perovskite quantum dots, clean it with anhydrous ethanol, and vacuum dry it to obtain pretreated glass for later use; in ABX3, A is one or more of Cs⁺, CH3NH3⁺ (MA⁺), and CH(NH2)2⁺ (FA⁺), B is one or two of Pb²⁺ and Sn²⁺, and X is one or more of Cl⁻, Br⁻, and I⁻; the quantum dot particle size is 3-100 nm, and the mass fraction of quantum dots in the glass is 0.1%-10%; S2. Next, perform any one of the following three processes: S21. Place the pretreated glass in a vacuum irradiation chamber and irradiate it with an electron beam while moving it at a constant speed. The electron energy is 10-50 keV, the beam current density is 0.1-1 μA / cm², and the irradiation dose is greater than 0 klad and less than 240 klad, to obtain electron-irradiated glass. S22. Place the pretreated glass in a vacuum irradiation chamber and irradiate it with a proton irradiation source while moving it at a constant speed. The proton energy is 50-200keV, the beam current density is 0.05-0.5μA / cm², and the irradiation dose is greater than 0krad and less than 240krad to obtain proton-irradiated glass. S23. Place the pretreated glass in a gamma-ray irradiation device and irradiate it with a gamma-ray source. The irradiation dose is greater than 0 klad and less than 240 klad, and the dose rate is 0.1-1 kGy / h (to avoid overheating of quantum dots due to high dose rate) to obtain gamma-ray irradiated glass. S3. Vacuum drying is performed on electron-irradiated glass, proton-irradiated glass, or gamma-ray-irradiated glass to obtain glass with improved perovskite quantum dot defects.
[0007] The mechanism of the S21 treatment (low-energy electron irradiation) mentioned above is as follows: the energy of low-energy electrons can be precisely transferred to the lattice atoms of perovskite quantum dots, causing free vacancies and interstitial atoms in the lattice to migrate and form stable atomic bonds (such as causing iodine vacancies to recombine with free iodine atoms), reducing the number of point defects; at the same time, the electron beam can excite electron transitions in quantum dots, repair some shallow energy level defects, and reduce the density of non-radiative recombination centers.
[0008] The mechanism of the S22 treatment (low-energy proton irradiation) is as follows: protons have a certain mass and energy, which can form a slight "lattice reconstruction effect" in the perovskite quantum dot lattice. That is, through the elastic collision between protons and lattice atoms, the distorted lattice structure (such as the lattice distortion region generated after irradiation) is restored to an ordered arrangement. At the same time, the injection of protons can adjust the electronic state of the quantum dot, fill some deep energy level defects (such as the deep defect energy level formed by lead vacancies), and further improve the carrier separation efficiency.
[0009] The mechanism of the S23 treatment (low-flux gamma-ray irradiation) is as follows: gamma rays can penetrate into the interior of the glass matrix and perform deep and uniform treatment on the perovskite quantum dots embedded in the glass matrix; at the same time, the low-flux characteristic of gamma rays can avoid inducing new lattice defects, ensure the stability of the crystal structure of the quantum dots, and ultimately achieve a synergistic improvement in luminescence performance and radiation resistance performance.
[0010] In step S1, the purity of anhydrous ethanol is above 99.9% to remove surface oil and impurities; vacuum drying is carried out in a vacuum drying oven with a vacuum degree below 1×10⁻³Pa, a temperature of 60℃-80℃, and a time of 2-4 hours to eliminate residual moisture and organic solvents and avoid introducing additional defects during pretreatment; the glass is selected from one of quartz glass, borosilicate glass, or polymethyl methacrylate.
[0011] In step S21 of process S2, the vacuum level of the vacuum irradiation chamber is 5 × 10⁻ 4 Below Pa, the temperature is 25℃-40℃; the uniform moving speed is 5-10mm / min; the electron beam is generated by an electron gun, and the irradiation uniformity error of the electron beam on the pretreated glass surface is -5% to +5%.
[0012] In step S22 of process S2, the vacuum level of the vacuum irradiation chamber is 5 × 10⁻ 4 Below Pa, the temperature is 25℃-40℃; the uniform moving speed is 5-10mm / min; the proton irradiation source is generated by a cyclotron accelerator; the irradiation uniformity error of the proton beam on the pretreated glass surface is -5% to +5%.
[0013] In step S23 of process S2, the γ-ray source is a cobalt-60 γ-ray source. The irradiation uniformity error of the γ-ray on the pretreated glass surface is -5% to +5%. The glass temperature is kept below 50°C during the irradiation process. The irradiation can be carried out under normal temperature and pressure.
[0014] In step S3, vacuum drying is carried out in a vacuum drying chamber with a vacuum degree below 1×10⁻³Pa, a temperature of 50℃-70℃, and a time of 1-2 hours to remove trace gases (such as HX gas, where X represents Cl⁻, Br⁻, or I⁻) that may be generated during irradiation.
[0015] The present invention also provides a glass obtained using the above-described irradiation method for improving defects in perovskite quantum dots.
[0016] The present invention also provides a perovskite quantum dot solar cell comprising the glass described above.
[0017] Beneficial effects: The irradiation method of this invention is highly targeted, addressing the main irradiation defects of perovskite quantum dots in aerospace environments. It employs low-energy electron, low-energy proton, and low-flux gamma-ray irradiation, with irradiation parameters precisely matching the crystal structure and electronic state characteristics of quantum dots, avoiding the introduction of new defects by traditional modification methods. It is suitable for aerospace applications, with environmental parameters such as temperature and vacuum simulating the on-orbit working conditions of spacecraft. Furthermore, the treated object is a quantum dot system embedded in glass / plexiglass (meeting the requirements of lightweight and integrated materials for spacecraft), which can be directly applied to the preparation and performance optimization of aerospace perovskite solar cells. The operation is simple and scalable. The entire irradiation process does not require complex chemical modification steps and can be achieved using existing vacuum irradiation equipment and gamma-ray irradiation devices, making it easy to scale up industrial production and providing technical support for the large-scale application of perovskite quantum dot solar cells in the aerospace field. Attached Figure Description
[0018] Figure 1The images show low-dose CsPbBr3 TEM images of perovskite quantum dot defects before and after glass irradiation in Example 3; where (a)-(c) are TEM images of CsPbBr3 quantum dots at doses of 0 klad (Si), 120 klad (Si), and 240 klad (Si); and (d)-(f) are HRTEM images of CsPbBr3 quantum dots at doses of 0 klad (Si), 120 klad (Si), and 240 klad (Si). Figure 2 The images show CsPbBr3 TEM images of perovskite quantum dot defects after high-dose glass irradiation in Example 3; where (a)-(b) are TEM images of CsPbBr3 quantum dots at doses of 360 klad(Si) and 540 klad(Si); and (c)-(d) are HRTEM images of CsPbBr3 quantum dots at doses of 360 klad(Si) and 540 klad(Si). Figure 3 The images show the size distribution and XRD patterns of CsPbBr3 in perovskite quantum dot defects before and after glass irradiation in Example 3; where (a) is the size distribution of CsPbBr3 at different doses; and (b) is the XRD pattern at different doses. Figure 4 The images show the PL and temperature-dependent spectra of the perovskite quantum dot defects in Example 3 before and after glass irradiation; where (a) is the absorption spectrum of CsPbBr3 at different doses; (b) is the PL spectrum of CsPbBr3; (c) is the temperature-dependent spectrum of CsPbBr3 before irradiation; and (d) is the temperature-dependent spectrum of CsPbBr3 after irradiation. Figure 5 The images show the temperature-varying spectra of CsPbBr3 in the perovskite quantum dot defect glass of Example 3 at different doses and the corresponding curve fitting diagrams; where (a) is 0 krad; (b) is 120 krad irradiation dose; (c) is 240 krad irradiation dose; and (d) is 540 krad irradiation dose. Detailed Implementation
[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, but the present invention is not limited to the embodiments.
[0020] Example 1
[0021] Quartz glass embedded with CsPbBr3 quantum dots (quantum dot particle size 3-100nm, quantum dot mass fraction in glass 0.1%-10%) was selected. The sample surface was thoroughly cleaned with 99.9% pure anhydrous ethanol, and then placed in a vacuum drying oven and dried for 3h under a vacuum of 1×10⁻³Pa and a temperature of 70℃ to obtain pretreated glass for later use.
[0022] The pretreated glass was placed in the vacuum irradiation chamber, and the vacuum level was adjusted to 5×10⁻. 4 At a temperature of 30℃, the pre-treated glass is moved at a constant speed of 8 mm / min via a displacement platform, while a low-energy electron beam generated by an electron gun irradiates the pre-treated glass. The electron energy is 30 keV, the beam current density is 0.5 μA / cm², and the irradiation dose is 120 krad. The electron beam is ensured to uniformly cover the surface of the pre-treated glass (uniformity error is -5% to +5%), resulting in electron-irradiated glass.
[0023] The electron-irradiated glass was placed in a vacuum drying oven and dried under vacuum conditions of 1×10⁻³Pa and 70℃ for 2 hours to obtain glass with improved perovskite quantum dot defects.
[0024] Perovskite quantum dot solar cells were fabricated using the glass obtained above that improved the defects of perovskite quantum dots.
[0025] Example 2
[0026] Quartz glass embedded with CsPbBr3 quantum dots (quantum dot particle size 3-100nm, quantum dot mass fraction in glass 0.1%-10%) was selected. The sample surface was thoroughly cleaned with 99.9% pure anhydrous ethanol, and then placed in a vacuum drying oven and dried for 3h under a vacuum of 1×10⁻³Pa and a temperature of 70℃ to obtain pretreated glass for later use.
[0027] The pretreated glass was placed in the vacuum irradiation chamber, and the vacuum level was adjusted to 5×10⁻. 4 At a temperature of 30℃, the pretreated glass is moved at a constant speed of 8 mm / min via a displacement platform while a proton irradiation source generated by a cyclotron accelerator is used to irradiate the pretreated glass. The proton energy is 100 keV, the beam current density is 0.2 μA / cm², and the irradiation dose is 120 krad. The proton beam is ensured to uniformly cover the surface of the pretreated glass (uniformity error is -5% to +5%), resulting in proton-irradiated glass.
[0028] The proton-irradiated glass was placed in a vacuum drying oven and dried under vacuum conditions of 1×10⁻³Pa and 70℃ for 2 hours to obtain glass with improved perovskite quantum dot defects.
[0029] Perovskite quantum dot solar cells were fabricated using the glass obtained above that improved the defects of perovskite quantum dots.
[0030] Example 3
[0031] Quartz glass embedded with CsPbBr3 quantum dots (quantum dot particle size 3-100nm, quantum dot mass fraction in glass 0.1%-10%) was selected. The sample surface was thoroughly cleaned with 99.9% pure anhydrous ethanol, and then placed in a vacuum drying oven and dried for 3h under a vacuum of 1×10⁻³Pa and a temperature of 70℃ to obtain pretreated glass for later use.
[0032] The pretreated glass was placed in a gamma-ray irradiation device and irradiated at room temperature using a cobalt-60 gamma-ray source. The irradiation doses were 0, 120 krad, 240 krad, 360 krad, and 540 krad, and the dose rate was 0.5 kGy / h (it was ensured that the glass temperature was kept below 50°C during the irradiation process). The gamma rays were also ensured to uniformly cover the surface of the pretreated glass (uniformity error of -5% to +5%), resulting in gamma-ray irradiated glass.
[0033] The glass treated with gamma rays was placed in a vacuum drying oven and dried under vacuum conditions of 1×10⁻³Pa and 70℃ for 2 hours to obtain glass with improved perovskite quantum dot defects.
[0034] Perovskite quantum dot solar cells were fabricated using the glass obtained above that improved the defects of perovskite quantum dots.
[0035] Performance testing
[0036] The performance of the glass with improved perovskite quantum dot defects in Example 3 was tested. High-resolution transmission scanning electron microscopy was used to analyze the changes in the microstructure of the perovskite quantum dots. It was found that as the irradiation dose increased from 0 to 360 klad(Si), the average particle size increased from 12 nm to 17 nm. After irradiation, excess atoms remaining in the glass-ceramic during the preparation process grew into new perovskite nanocrystals under gamma-ray drive, thus covering the original CsPbBr3 NCs (quantum dots) and increasing the perovskite particle size. However, when the irradiation dose increased to more than 360 klad(Si), the CsPbBr3 NCs decomposed into smaller particles, indicating nanocrystal degradation. Furthermore, when the dose increased to 540 klad(Si), large-scale aggregation of particles occurred, such as... Figure 1 (a)- Figure 1 (f) and Figure 2 (a)- Figure 2 As shown in (d).
[0037] Crystal structure is analyzed using X-ray diffraction (XRD), such as... Figure 3The image shows the X-ray diffraction (XRD) patterns of CsPbBr3 NCs under different doses of gamma irradiation. Since the sample is coated with glass-ceramics, the overall crystallinity is not very good, and no obvious diffraction peaks are observed. However, the CsPbBr3 (110) crystal plane at 21.6°, the (111) plane at 26.5°, and the (200) plane at 30.6° can still be observed, indicating the presence of CsPbBr3 in the glass-ceramics. Furthermore, the perovskite exhibits excellent irradiation stability under gamma rays.
[0038] Steady-state ultraviolet-infrared absorption spectroscopy (UV-VIS), photoluminescence (PL), and time-resolved photoluminescence spectroscopy (TRPL) were used to investigate the optical properties of the materials. The study revealed a clear observation of enhanced light absorption, with PNC-240 exhibiting the strongest absorption performance. Figure 4 (a)). A slight redshift of the characteristic absorption edge can be clearly observed, which is radiation-induced modulation of the electronic structure. In addition, photoluminescence (PL) experiments were conducted on CsPbBr3 NCs at different doses ( Figure 4 (b) The photoluminescence properties of CsPbBr3 NCs are enhanced at 0-240 klad(Si), but gradually decrease at 360 klad(Si) and 540 klad(Si), a phenomenon consistent with light absorption. The photoluminescence intensity variation trend of CsPbBr3 NCs at different temperatures was compared using temperature-dependent spectroscopy to further investigate the mechanism of the enhanced luminescence of PNC-240 at low temperatures and to explore its intrinsic luminescence mechanism. Figure 4 (d) When the temperature increases from 4K to 294K, the PL spectrum shows an increase in full width at half maximum (FWHM) and a decrease in photoluminescence intensity. This phenomenon is related to the suppression of nonradiative recombination at low temperatures. Time-resolved photoluminescence spectroscopy (TRPL) was used to investigate data related to exciton recombination and carrier lifetime. Figure 5 (a)- Figure 5 (d) It can be seen that the irradiated samples have a longer carrier lifetime, with PNC-240 showing a 19% increase in carrier lifetime. The TRPL data were subjected to a bi-exponential fit, and the lifetime fitting results for the original and irradiated samples are listed in Table 1 below. Slow recombination center lifetime. The average lifetime of the composite center was increased by 15% after irradiation. The lifetime increased by 18% from 738 ns to 875 ns. The improvement in carrier lifetime is due to the significant reduction in the defect density of CsPbBr3 NCs by interaction with gamma rays.
[0039] Table 1. Lifetime fitting results of perovskites before and after irradiation
[0040] Unless otherwise specified, all technologies mentioned above refer to existing technologies.
[0041] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification.
Claims
1. An irradiation method for improving defects in perovskite quantum dots, characterized in that, Includes the following steps, S1. Select glass embedded with ABX3 perovskite quantum dots, clean it with anhydrous ethanol, and vacuum dry it to obtain pretreated glass for later use; in ABX3, A is one or more of Cs⁺, CH3NH3⁺, and CH(NH2)2⁺, B is one or two of Pb²⁺ and Sn²⁺, and X is one or more of Cl⁻, Br⁻, and I⁻; the quantum dot particle size is 3-100 nm, and the mass fraction of quantum dots in the glass is 0.1%-10%; S2. Next, perform any one of the following three processes: S21. Place the pretreated glass in a vacuum irradiation chamber and irradiate it with an electron beam while moving it at a constant speed. The electron energy is 10-50 keV, the beam current density is 0.1-1 μA / cm², and the irradiation dose is greater than 0 klad and less than 240 klad, to obtain electron-irradiated glass. S22. Place the pretreated glass in a vacuum irradiation chamber and irradiate it with a proton irradiation source while moving it at a constant speed. The proton energy is 50-200keV, the beam current density is 0.05-0.5μA / cm², and the irradiation dose is greater than 0krad and less than 240krad to obtain proton-irradiated glass. S23. Place the pretreated glass in a γ-ray irradiation device and irradiate it with a γ-ray source. The irradiation dose is greater than 0 klad and less than 240 klad, and the dose rate is 0.1-1 kGy / h to obtain γ-ray irradiated glass. S3. Vacuum drying is performed on electron-irradiated glass, proton-irradiated glass, or gamma-ray-irradiated glass to obtain glass with improved perovskite quantum dot defects.
2. The irradiation method for improving defects in perovskite quantum dots according to claim 1, characterized in that, In step S1, the vacuum drying process is performed at a vacuum level of less than 1×10⁻³Pa, a temperature of 60℃-80℃, and a time of 2-4 hours; the glass is selected from quartz glass, borosilicate glass, or polymethyl methacrylate.
3. The irradiation method for improving defects in perovskite quantum dots according to claim 1, characterized in that, In step S21 of process S2, the vacuum level of the vacuum irradiation chamber is 5 × 10⁻ 4 Below Pa, the temperature is 25℃-40℃; the uniform moving speed is 5-10mm / min; the electron beam is generated by an electron gun, and the irradiation uniformity error of the electron beam on the pretreated glass surface is -5% to +5%.
4. The irradiation method for improving defects in perovskite quantum dots according to claim 1, characterized in that, In step S22 of process S2, the vacuum level of the vacuum irradiation chamber is 5 × 10⁻ 4 Below Pa, the temperature is 25℃-40℃; the uniform moving speed is 5-10mm / min; the proton irradiation source is generated by a cyclotron accelerator; the irradiation uniformity error of the proton beam on the pretreated glass surface is -5% to +5%.
5. The irradiation method for improving defects in perovskite quantum dots according to claim 1, characterized in that, In step S23 of process S2, the γ-ray source is a cobalt-60 γ-ray source, the irradiation uniformity error of the γ-ray on the pretreated glass surface is -5% to +5%, and the glass temperature is kept below 50°C during the irradiation process.
6. The irradiation method for improving defects in perovskite quantum dots according to claim 1, characterized in that, In step S3, the vacuum degree of vacuum drying is below 1×10⁻³Pa, the temperature is 50℃-70℃, and the time is 1-2h.
7. A type of glass, characterized in that, Obtained using the irradiation method for improving defects in perovskite quantum dots as described in any one of claims 1-6.
8. A perovskite quantum dot solar cell, characterized in that, It includes the glass described in claim 7.