WO2021212942A1 - 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法 - Google Patents

一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法 Download PDF

Info

Publication number
WO2021212942A1
WO2021212942A1 PCT/CN2021/073527 CN2021073527W WO2021212942A1 WO 2021212942 A1 WO2021212942 A1 WO 2021212942A1 CN 2021073527 W CN2021073527 W CN 2021073527W WO 2021212942 A1 WO2021212942 A1 WO 2021212942A1
Authority
WO
WIPO (PCT)
Prior art keywords
perovskite
temperature
film
quantum yield
low
Prior art date
Application number
PCT/CN2021/073527
Other languages
English (en)
French (fr)
Inventor
方国家
刘永杰
刘陈威
Original Assignee
武汉大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 武汉大学 filed Critical 武汉大学
Publication of WO2021212942A1 publication Critical patent/WO2021212942A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/10—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising heterojunctions between organic semiconductors and inorganic semiconductors
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/80—Constructional details
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/80—Constructional details
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/10—Deposition of organic active material
    • H10K71/12—Deposition of organic active material using liquid deposition, e.g. spin coating
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H10K71/40—Thermal treatment, e.g. annealing in the presence of a solvent vapour
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/549—Organic PV cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the invention belongs to the field of nano material preparation and luminescence application, and mainly relates to a perovskite film with low-temperature doping and high photoluminescence quantum yield and a preparation method thereof.
  • Perovskite materials have excellent properties such as fewer deep-level defects, long carrier lifetime, and large absorption coefficient, which have attracted the attention of the majority of researchers. Thanks to the rapid development of perovskite batteries, research has found that perovskite materials can be used not only in batteries, but also in light-emitting diodes. As the efficiency of the perovskite cell has increased from 3.9% to 24.2%, the efficiency of the perovskite light-emitting diode has also increased from 0.76% to 28.2%, despite the curse of the coupling light layer. In the case of the non-coupling light-emitting layer blessing, the efficiency of more than 20% can also be achieved in the red and green wavelength bands. However, the perovskite film materials in the electroluminescent devices described above perform poorly in terms of fluorescence.
  • the perovskite material itself has the characteristics of adjustable band gap, and the perovskite fluorescent material made on this basis can cover the full range of visible light.
  • Perovskite fluorescent materials are mainly in the form of liquid quantum dots and solid fluorescent powders and films, among which liquid quantum dots have the highest fluorescence efficiency.
  • the preparation method of quantum dots is mainly based on the high-temperature thermal injection method, and the perovskite is made into a one-dimensional structure. Thanks to the quantum confinement effect, the one-dimensional perovskite quantum dots show a high fluorescence yield.
  • the domestic Zeng Haibo group has produced many perovskite quantum dot materials with a fluorescence efficiency of more than 90. Most of the perovskite films synthesized by the non-quantum dot process only have a fluorescence efficiency of 20% to 70%.
  • the internationally leading Richard H. Friend group reduces the fluorescence quenching of the perovskite through the special surface characteristics of the polymer layer of the electron transport layer, and also makes the near-infrared photoluminescence efficiency of the perovskite reach 85%.
  • the synthesis of high-efficiency quantum dots also has its drawbacks.
  • the preparation process is extremely cumbersome, and the cost caused by high temperature conditions is high.
  • the addition of ligands such as oleylamine not only causes the cumbersome process, but also has a great impact on the electrical properties of the perovskite.
  • the rare-earth-doped photoluminescent nanocrystalline perovskite material has the advantages of high photochemical stability, long luminescence life, narrow absorption and emission bands, and tunable fluorescence emission wavelength, making it have advantages that other fluorescent materials cannot match.
  • perovskite materials photogenerated excitons generated by light excitation recombine inside the perovskite. If non-radiative recombination occurs, energy exchange with phonons will generate heat; on the contrary, if recombination occurs in the form of radiative recombination It will re-release energy in the form of photons to emit light. Therefore, in order to improve the efficiency of photoluminescence, it is necessary to increase the probability of radiation recombination.
  • the method is to inhibit non-radiation recombination, and from the perspective of material nature, it is necessary to reduce non-radiation recombination defect centers.
  • Mn 2+ , Bi 3+ , Cr 3+ and other transition metals are doped at B site to reduce the content of Pb to change the characteristics of the PbX 6 octahedron and increase the stability of the optoelectronic device.
  • the band structure cannot directly participate in the exciton recombination, nor can it substantially change the exciton recombination of perovskite, a variable band gap material.
  • Lanthanide metals have a rich energy level structure because of their 4f energy levels with different numbers of electrons. According to existing reports, they have more than 1,800 transition modes.
  • the radiation band covers a wide range of wavelengths from ultraviolet to near-infrared.
  • the energy levels of perovskite are very matched, laying the foundation for doping perovskite.
  • the initial doping of lanthanide metals was used to improve the magnetic and electrical properties of ionic compounds.
  • Kumamoto University in Japan reported that lanthanum-doped perovskite nanosheets La 0.7 Tb 0.3 Ta 2 O 7 were in aqueous solution. It has strong red and green luminescence.
  • ODE octadecene
  • OA oleic acid
  • OVA oleic acid amine
  • the doping of transition metals can change a certain material stability without qualitatively improving the luminescence performance; the improvement of the luminous efficiency of pure inorganic perovskite brought by a few lanthanide metals is due to its ion luminescence
  • the peak position is coupled with the perovskite corresponding to the blue emission, and most of it comes from the intrinsic luminescence of the ion, and the solubility of the all-inorganic perovskite is very low. It is difficult to achieve high-performance luminescence without organic cations.
  • the process of perovskite nucleation and growth greatly affects its optoelectronic properties. In the face of perovskite, a magical optoelectronic material, there is an urgent need for a simple, universal, low-cost preparation method to improve its application potential. .
  • the present invention provides a low-temperature doped perovskite film with high photoluminescence quantum yield and a preparation method thereof.
  • the present invention adopts a one-step method to prepare metal lanthanum ion-doped perovskite precursor solution under low temperature conditions.
  • Reasonable control of aging conditions is beneficial to ensure the stability of organic cations and the phase stability of thin-film perovskites.
  • the hot substrate facilitates the volatilization of the solvent during the spin coating process to accelerate the rate of nucleation and crystallization.
  • high-polarity chloroform as the anti-solvent is more conducive to quickly absorbing the volatile solvent to reduce the vapor pressure of the solvent and accelerate the volatilization of the solvent, so that the perovskite can quickly nucleate from the precursor liquid.
  • Annealing with temperature gradient conventional pre-annealing at a low temperature of 50°C is conducive to uniform nucleation and grain growth; post-annealing in a solvent atmosphere at 70°C, solvent molecules enter the grain gap, which is conducive to the reorganization and re-growth of grains.
  • the use of lanthanum ion doping to transfer the photogenerated excitons to the composite site of the perovskite material substantially improves the photoluminescence quantum yield of the perovskite material.
  • the present invention prepares three different color fluorescent emission perovskite films by doping with lanthanum, and the prepared organic-inorganic hybrid green fluorescent perovskite film photoluminescence quantum yield peak value is increased from 17.3% ( ⁇ 0.3%) to 98 %( ⁇ 0.3%); Due to the process and excitation source power, the PL fluorescence peak of the undoped blue and red perovskite films is not detected. After lanthanum doping, the fluorescence efficiency of the perovskite film has a certain degree The degree of improvement.
  • the XRD pattern of the prepared lanthanum-doped polycrystalline perovskite film shows that it has the characteristic peak of the perovskite ⁇ phase without the appearance of impurity phases.
  • the method does not require a complicated preparation process and redundant ligand injection, and the doped precursor solution can be subjected to low-temperature gradient annealing and solvent atmosphere annealing to obtain a perovskite film with high fluorescence performance.
  • the present invention shows through experiments that metal lanthanum ions doped with perovskites with different band gaps have the effect of improving the photoluminescence efficiency, and can basically experiment with the fluorescence of the three primary colors of red, green and blue.
  • the unique rich energy level structure of metal lanthanum ions and the different band gaps of perovskites have a certain synergistic matching effect.
  • the doping of metal lanthanum ions into the lattice easily forms relatively many shallow-level defects, which promotes more energy transfer from the intrinsic energy level of the lanthanide ions to the perovskite At the ore energy level, the high-energy excitons undergo transition recombination at the perovskite band gap, thereby improving the luminous efficiency.
  • the excess lanthanide metal is transferred to the grain boundary, and at the same time, it can effectively reduce the non-radiative recombination pathway in the exciton transition process.
  • the perovskite crystal structure is usually expressed as ABX 3 , the A position usually refers to an organic cationic group or Cs, the B position is usually Pb, and the X position usually refers to a halogen element.
  • lanthanum atoms replace part of lead atoms to form B-site doping. The doping and atom replacement methods are shown in Figure 1.
  • the gradient annealing process has an effect on the internal defects of the crystal, but has no substantial effect on the morphology of the micro-area.
  • the prepared perovskite film exhibits different colors and transparency due to the difference of halogen; the fluorescence of the lanthanum-doped perovskite polycrystalline film has a color purity of more than 90%, as shown in Figure 8 for details.
  • One of the objectives of the present invention is to provide a method for preparing a low-temperature doped perovskite film with high photoluminescence quantum yield, which includes the following steps:
  • the precursor solution is divided into sky blue fluorescent perovskite precursor liquid, green fluorescent perovskite precursor liquid and red fluorescent perovskite precursor liquid according to the difference in composition;
  • the halide salt M used in the sky blue fluorescent perovskite precursor solution is CsCl
  • the lead halide is PbBr 2
  • the lanthanum halide is LaCl 3 ;
  • the halide salt M used in the green fluorescent perovskite precursor solution is CsBr and FABr, the lead halide is PbBr 2 , and the lanthanum halide is LaBr 3 ;
  • the halogen salt M used in the red fluorescent perovskite precursor solution is MAI
  • the lead halide is PbI 2
  • the lanthanum halide is LaI 3 .
  • the solvent S is a mixed solvent of dimethylformamide and dimethyl sulfoxide, which is beneficial to the dissolution of the halogen ions of the precursor and the extraction of the solvent by the anti-solvent chloroform.
  • the volume ratio of dimethylformamide and dimethyl sulfoxide is 1:9.
  • the constant temperature stirring reaction temperature is 60°C
  • the reaction time is 6h
  • the aging temperature is 20-28°C
  • the aging time is 10-14h.
  • the temperature of the heated glass substrate in the step (3) is 50°C.
  • the hot substrate facilitates the volatilization of the solvent during the spin coating process to accelerate the rate of nucleation and crystallization.
  • the dripping of the anti-solvent needs to be within a window period of 3 to 5 seconds before the film is discolored, and the anti-solvent is chloroform.
  • the high polarity of chloroform is more conducive to the rapid absorption of volatile solvents, thereby reducing the vapor pressure of the solvent and accelerating the volatilization of the solvent, so that the perovskite can quickly nucleate from the precursor liquid.
  • the room temperature storage time in the step (5) is 20-30s.
  • the pre-annealing method in the step (5) is: annealing at 50° C. for 1 minute. Low-temperature pre-annealing is conducive to uniform nucleation and grain growth.
  • the post-annealing method in the step (5) is: annealing in a solvent S atmosphere at 70°C to 100°C for 4 minutes. Under solvent annealing conditions, the entry of solvent molecules into the crystal grains facilitates the reorganization and re-growth of the crystal grains.
  • the second objective of the present invention is to provide a perovskite film with high photoluminescence quantum yield prepared by the above method.
  • the prepared perovskite film has a significantly improved photoluminescence quantum yield, especially the organic-inorganic hybrid bromine-based green fluorescence, which has great application potential;
  • the prepared perovskite film is composed of many nanometer blocks, and there are a large number of pores, which improves the light coupling rate;
  • Fig. 1 is a schematic diagram of lanthanum-doped perovskite crystal prepared by the present invention
  • Figure 2 is a schematic diagram of the annealing method and the principle of solvent annealing used in the present invention
  • Figure 3 is a schematic diagram of the solvent annealing operation of the present invention.
  • Figure 4 is a scanning electron microscope (SEM) image of the perovskite films prepared in Example 1 and Comparative Examples 1 and 3;
  • Figure 4(a) corresponds to Comparative Example 3
  • Figure 4(b) corresponds to the comparative implementation Example 1
  • Figure 4(c) corresponds to Example 1;
  • Figure 5 is the SEM images of the perovskite films prepared in Examples 2 and 3 and Comparative Examples 4 and 5 respectively, in which Figure 5(a) corresponds to Comparative Example 5, and Figure 5(b) corresponds to Example 3; Figure 5(c) corresponds to Comparative Example 4, and Figure 5(d) corresponds to Example 2;
  • Fig. 6 is an X-ray diffraction (XRD) chart of a perovskite thin film, in which Fig. 6(a) corresponds to Example 3 and Comparative Example 5, and Fig. 6(b) corresponds to Example 1 and Comparative Example 3, and Fig. 6(c) ) Corresponding to Example 2 and Comparative Example 4;
  • XRD X-ray diffraction
  • Figure 7 is the absorption and photoluminescence curves of the prepared perovskite film;
  • Figure 7 (a) corresponds to Example 3 and Comparative Example 5
  • Figure 7 (b) corresponds to Example 1 and Comparative Example 3
  • Figure 7 ( c) Corresponding to Example 2 and Comparative Example 4;
  • Figure 8(a) is an optical photograph of the obtained three different color fluorescent perovskite films. From top to bottom, they are prepared in Example 2, Comparative Example 1, Example 1, Comparative Example 4, and Example 3.
  • Figure 8(b) shows the position of the fluorescence characteristics of the three lanthanum-doped films on the CIE color coordinate diagram. The red, green and blue regions correspond to Example 2, Example 1, and Example 3 respectively;
  • Fig. 9(a) is a graph showing the relationship between the aging time and efficiency of the green fluorescent perovskite precursor solution in Example 1;
  • Fig. 9(b) is a statistical graph showing the efficiency of annealing the green fluorescent perovskite in different ways;
  • Fig. 10 is a photoluminescence test curve of a green fluorescent perovskite film with a photoluminescence quantum yield of 98% of the perovskite film prepared in Example 1 and a non-lanthanum-doped film in Comparative Example 3, with a 365nm peak For the light source peak.
  • Substrate preparation In the present invention, a glass substrate is used. First, the substrate is cut into a suitable size (2cm ⁇ 2cm), and then deionized water, acetone, isopropanol, and absolute ethanol are used for ultrasonic cleaning in an ultrasonic cleaner. 15min, then dry it with nitrogen, and process it in a UV cleaning ozone machine with a power of 40W for 15min to obtain a clean substrate.
  • the precursor solution is divided into sky blue fluorescent perovskite precursor liquid, green fluorescent perovskite precursor liquid and red fluorescent perovskite precursor liquid according to the difference in composition;
  • the halide salt M used in the sky blue fluorescent perovskite precursor solution is CsCl
  • the lead halide is PbBr 2
  • the lanthanum halide is LaCl 3 ;
  • the halide salt M used in the green fluorescent perovskite precursor solution is CsBr and FABr, the lead halide is PbBr 2 , and the lanthanum halide is LaBr 3 ;
  • the halogen salt M used in the red fluorescent perovskite precursor solution is MAI
  • the lead halide is PbI 2
  • the lanthanum halide is LaI 3 .
  • the solvent S is a mixed solvent of dimethylformamide and dimethylsulfoxide.
  • the volume ratio of dimethylformamide and dimethyl sulfoxide is 1:9.
  • the constant temperature stirring reaction temperature is 60°C
  • the reaction time is 6h
  • the aging temperature is 20-28°C
  • the aging time is 10-14h.
  • the temperature of the heated glass substrate in the step (3) is 50°C.
  • the dropwise addition of the anti-solvent needs to be within a window period of 3 to 5 seconds before the film is discolored, and the anti-solvent is chloroform.
  • the room temperature storage time in the step (3) is 20-30s.
  • the pre-annealing method in the step (3) is: annealing at 50° C. for 1 minute.
  • the method of post-annealing in the step (3) is: annealing in a solvent S atmosphere at 70°C to 100°C for 4 minutes.
  • the prepared photoluminescence efficiency test Move the annealed glass sheet to the test glove box, LQ-100 test system, use 365nmLED excitation source to excite the perovskite film, deduct the background, and test the photoluminescence quantum yield.
  • This embodiment provides a method for preparing a green fluorescent perovskite film.
  • the perovskite film is prepared, wherein the post-annealing temperature is 70°C.
  • Figure 2 is a schematic diagram of gradient annealing followed by solvent annealing during the preparation of perovskite film. Gradient annealing prevents uneven nucleation and film cracks caused by solvent volatilization. Solvent annealing is used to crystallize small crystals. Recombination and growth is conducive to the improvement of crystal quality. The specific operation of solvent annealing is shown in Figure 3.
  • the conventional annealed lanthanum-doped green fluorescent perovskite film was prepared.
  • the preparation method and the amount of raw materials were the same as those in Example 1, except that the annealing was conventional annealing, that is, direct annealing at 70°C after being placed at room temperature.
  • the gradient-annealed lanthanum-doped green fluorescent perovskite film was prepared.
  • the preparation method and the amount of raw materials were the same as those in Example 1, except that solvent annealing was not used, that is, direct gradient annealing.
  • a green fluorescent perovskite film without lanthanum is prepared.
  • the preparation method and the amount of raw materials are the same as in Example 1, except that LaBr 3 is not added, and the conventional annealing method is used, that is, direct annealing at 70° C. after being placed at room temperature.
  • Figure 4 shows scanning electron microscope (SEM) images of the perovskite films prepared in Comparative Example 3 ( Figure 4a), Comparative Example 1 ( Figure 4b) and Example 1 ( Figure 4c). It can be seen from the figure: 1) Compared with the undoped perovskite, the crystal grains grow up after doping with lanthanum, and the crystal crystal quality is obviously improved; 2) Through the gradient annealing and the solvent atmosphere post-annealing, the polycrystalline film undergoes grain reorganization and reorganization. The phenomenon of growth, the crystal quality is further improved.
  • SEM scanning electron microscope
  • Figure 6(b) is the X-ray diffraction pattern of the perovskite film of Comparative Example 3 and Example 1. It can be seen that 1) the crystallinity is improved and there is no impurity phase; 2) the peak position shifts slightly to a large angle, the source The lattice shrinkage caused by doping causes the band gap to increase, which corresponds to the blue shift of absorption.
  • Figure 7(b) is the ultraviolet-visible absorption curve photoluminescence spectrum curve of the prepared film, where "Example 1 Abs” and “Comparative Example 3 Abs” are the perovskite films prepared in Example 1 and Comparative Example 3, respectively "Example 1PL” represents the photoluminescence spectrum curve of the perovskite film prepared in Example 1.
  • Figure 9(a) shows the relationship between the photoluminescence quantum yield of the perovskite film prepared in Example 1 and the aging time. It can be seen from the figure that the efficiency can be 95% when the aging time is between 10h and 14h. Above, there is repetitive operation;
  • Figure 9(b) is a statistical graph of photoluminescence quantum yields of different annealing methods. The results show that: compared with one-step conventional annealing at 70°C, through gradient annealing and solvent annealing, the photoluminescence quantum yield can be improved From 82.4% to 98.0%, the increase rate reached nearly 20%.
  • Figure 10 is a photoluminescence quantum yield test curve, in which the 365nm peak position is the peak of the excitation light source.
  • the perovskite film prepared in Comparative Example 3 is tested and the PLQY peak is calculated to be 17.3%.
  • the perovskite film prepared in Example 1 is tested The peak value of PLQY is calculated to be 98.0%. It can be seen that the fluorescence intensity is greatly improved after doping with lanthanum.
  • This embodiment provides a method for preparing a red fluorescent perovskite film.
  • the perovskite film is prepared according to the method in step 3) of the above specific embodiment, wherein the post-annealing temperature needs to be set to 100° C., and other conditions remain unchanged.
  • the preparation method and raw materials are the same as in Example 2, except that LaI 3 is not added.
  • FIG. 5c is the SEM image of the perovskite film prepared in Comparative Example 4
  • FIG. 5d is the SEM image of the perovskite film prepared in Example 2.
  • the comparison shows that: 1) Compared with the undoped perovskite, the crystal grains grow up after doping with lanthanum, with a certain degree of dispersibility, and the crystal crystallization quality is significantly improved; 2) Through gradient annealing and post-annealing in solvent atmosphere, polycrystalline film is formed The phenomenon of grain reorganization and regrowth.
  • Figure 6(c) is the X-ray diffraction pattern of the perovskite film prepared in Example 2 and Comparative Example 4. It can be seen that 1) the crystallinity is improved without the appearance of impurity; 2) the peak position is slightly larger The angular shift originates from the lattice shrinkage caused by doping, which leads to an increase in the band gap, which corresponds to the blue shift in absorption.
  • Figure 7(c) is the ultraviolet-visible absorption curve photoluminescence spectrum curve of the prepared film, in which "Example 2Abs", “Comparative Example 4Abs” and “Example 2PL” are similar to the “implementation” in Figure 7(b) “Example 1 Abs”, “Comparative Example 3 Abs” and “Example 1PL".
  • This embodiment provides a method for preparing a sky blue fluorescent perovskite film.
  • the perovskite film is prepared according to the method in step 3) of the foregoing specific embodiment, wherein the post-annealing temperature is 70° C., and other conditions remain unchanged.
  • a sky blue fluorescent perovskite film not doped with lanthanum was prepared, and the preparation method was the same as that in Example 3, except that LaCl 3 was not added.
  • FIG. 5a is an SEM image of the perovskite film prepared in Comparative Example 5
  • FIG. 5b is an SEM image of the perovskite film prepared in Example 3. It can be seen from the figure: 1) Compared with the undoped perovskite, the crystal grains grow to a certain extent after doping with lanthanum, but the film is more discontinuous, which is related to the solubility of chlorine; 2) through gradient annealing After annealing with a solvent atmosphere, the polycrystalline film also undergoes grain reorganization and regrowth.
  • Figure 6(a) is the X-ray diffraction pattern of the perovskite film prepared in Example 3 and Comparative Example 5. It can be seen that: 1) The low solubility of the conventional precursor liquid to the perovskite leads to poor film coverage. The overall crystalline performance is not good; 1) The characteristic peaks move slightly to a large angle, which is also caused by the shrinkage of the lattice caused by doping, which leads to an increase in the band gap, which corresponds to the blue shift of absorption.
  • Figure 7(a) is the ultraviolet-visible absorption curve photoluminescence spectrum curve of the prepared film, in which "Example 3Abs", “Comparative Example 5Abs” and “Example 3PL” are similar to the “implementation” in Figure 7(b) “Example 1 Abs”, “Comparative Example 3 Abs” and “Example 1PL”.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Optics & Photonics (AREA)
  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Luminescent Compositions (AREA)
  • Electroluminescent Light Sources (AREA)

Abstract

本发明涉及一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法。本发明采用低温前驱液金属镧离子掺杂，无需高温注入和绝缘配体辅助结晶即可得到高荧光量子产率钙钛矿薄膜。对于带隙不同的钙钛矿，都可以进行金属镧离子掺杂，在365nm激光激发下基本可以得到红绿蓝三原色荧光发射。所述的方法在相对低温环境下，通过温度梯度退火和溶剂氛围退火，制备的钙钛矿晶体质量更高，缺陷更少，非辐射复合路径被有效抑制。所制备的钙钛矿薄膜在半导体发光领域具有良好的应用前景，其高效、简单的制备方法对于钙钛矿材料的商业化应用具有极大的潜力。

Description

一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法 技术领域
本发明属于纳米材料制备及发光运用领域，主要涉及一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法。
背景技术
钙钛矿材料具有深能级缺陷少、载流子寿命长和吸光系数大等优异性能而受广大研究者的关注。得益于钙钛矿电池的迅猛发展，经研究发现，钙钛矿材料不仅能用到电池里，在发光二极管里面也大有可为。随着钙钛矿电池效率从3.9％提升到24.2％，钙钛矿发光二极管效率也从0.76％提升到了28.2％，虽然有耦合出光层的加持。在非耦合出光层加持的情况下也能在红光和绿光波段做到20％以上的效率。但是以上所述电致发光器件中的钙钛矿薄膜材料在荧光方面表现的差强人意。
近年来，光致发光材料应用愈发广泛，特别在光学仪器、生物、医疗等领域有着广阔的应用前景。而钙钛矿材料本身具有带隙可调的特点，在此基础上做的钙钛矿荧光材料可覆盖在可见光全波段范围。钙钛矿荧光材料形式主要是液体量子点和固体荧光粉末及薄膜，其中荧光效率最高的还是液体量子点。但是量子点的制备方法主要是以高温热注入法为主，将钙钛矿做成一维结构，得益于量子限域效应，一维钙钛矿量子点表现出很高的荧光产率。这一方面国内的曾海波组做出了很多荧光效率超过90的钙钛矿量子点材料。非量子点工艺合成的钙钛矿薄膜大都只有20％至70％的荧光效率。国际领先的Richard H.Friend组通过电子传输层高分子层的特殊表面特性减小了钙钛矿的荧光淬灭也使钙钛矿的近红外光致发光效率达到了85％。
类似的，依靠控制底层物质表面特性来减少钙钛矿荧光淬灭效应在钙钛矿光电器件中经常使用。但是，这种依靠外在物质减少荧光淬灭的策略大部分只能针对特定的钙钛矿和钝化层之间的耦合反应，无法得到一个普适的规律。
高效率量子点的合成也有其弊端，制备工艺极其繁琐，高温条件导致的成本高昂，油胺等配体的加入不仅造成了工艺的繁琐，更对钙钛矿电学性能产生极大的影响。
因此如何利用钙钛矿的带隙可调，可见光范围都具有发射的优点，找到低成本、简单地制备高荧光效率钙钛矿薄膜的普适性方法成为拓展钙钛矿荧光发展的关键因素。
稀土掺杂光致发光纳米晶钙钛矿材料具有光化学稳定性高、发光寿命长、吸收和发射带 窄，可调谐突光发射波长等优点，使其具有其它荧光材料无法比拟的优势。对于钙钛矿材料，光激发产生的光生激子在钙钛矿内部发生复合，如果发生非辐射复合，与声子进行能量交换就会产生发热现象；相反地，如果复合以辐射复合的形式发生就会以光子的形式重新释放能量从而发光。因此想要提高光致发光的效率，就需要提高辐射复合的几率，方法上来说就是抑制非辐射复合，从材料本质的角度来说就需要减少非辐射复合缺陷中心。
目前减少缺陷的方法有很多种，包括了表面分子钝化，降低维度，有机无机杂化，离子掺杂等。包括已经报道的镧系金属掺杂对钙钛矿电池的提升，都归功于晶粒尺寸的增大引起的界面缺陷的减少抑制光生载流子的复合，但是这些方法都普遍采用多步法或者高温热注入的方法，但对应于荧光薄膜来说工艺过于复杂，而且量子点以外，其他的途径很难达到高荧光效率。因此降低制备成本，简化制备工艺，提高荧光效率对钙钛矿荧光利用极为重要。
已经报道的Mn 2+、Bi 3+、Cr 3+等过渡金属进行B位掺杂，用于减少Pb的含量从而改变PbX 6八面体的特性从而增加光电器件的稳定性，但是由于其固定的能带结构，不能直接参与到激子复合中来，也不能对钙钛矿这种可变带隙材料的激子复合产生本质的改变。
镧系金属因为其4f能级具有不同的电子数而具有丰富的能级结构，据已有的报道称具有1800多种跃迁方式，辐射波段覆盖了从紫外到近红外大范围波段，这个波段与钙钛矿能级又非常匹配，奠定了掺杂钙钛矿的基础。最初的镧系金属的掺杂用于改善离子型化合物的磁学、电学相关性能，2007年，日本熊本大学报道的镧掺杂的钙钛矿型纳米片La 0.7Tb 0.3Ta 2O 7在水溶液中具有很强红色和绿色发光。2017年Hongwei Song等报道了利用十八烯(ODE)、油酸(OA)、油酸胺(OLA)在185℃条件下将Ce 3+、Sm 3+、Eu 3+、Tb 3+、Dy 3+、Er 3+、Yb 3+离子高温热注入到全无机CsPbCl 3钙钛矿纳米晶中，又通过阴离子交换法改变其卤素比例从而改变发光峰的位置，提高其光致发光性能，除开利用Yb 3+离子的本征发光在近红外波段达到超100％的荧光效率以外，其余离子掺杂最高做到了30％的荧光效率；2018年Song又在此基础上继续报道了在掺镧系金属之前制备K +掺杂的前驱液，从而制备A位B位双掺杂的钙钛矿量子点，并重点研究了Eu 3+离子掺杂量对荧光效率提升的影响，并最终在495nm处得到了89.9％的光致发光量子产率，Song的工作主要体现在量子限域达到的高荧光效率以及镧系金属掺杂导致的光生激子向镧系金属离子能带转移从而得到离子本征发光。2018年Tang Qunwei等人利用多步法将Sm 3+,Eu 3+,Tb 3+,Ho 3+,Er 3+,Yb 3+掺杂到全无机CsPbBr3钙钛矿薄膜并制备了太阳能电池器件，其对电池器件的提升归因于晶粒增大、界面缺陷的减少抑制光生载流子的复合，其对发光的贡献还未可知。还有同时期的Zeng Haibo课题组也利用油胺有机分子等高温热注入法合成有机无机杂化溴基钙钛矿量子点，其荧光效率也达到90％。
但以上的方式都具有一定的局限性。但是这若论量子点的合成，高温导致的高成本，多步注入过程繁琐，油胺等导电性不好的绝缘配体存在影响钙钛矿材料光电特性等。若论金属掺杂，过渡金属的掺杂能够改变一定的材料稳定性，对发光性能没有质的提升；少数镧系金属所带来的对纯无机钙钛矿发光效率的提高是因为其离子发光峰位与蓝光发射对应的钙钛矿相耦合，有大部分来自于离子本征发光，并且全无机钙钛矿的溶解度很低，没有有机阳离子很难达到高性能发光。本质上来说，钙钛矿成核和生长的过程极大地影响了其光电性能，而面对钙钛矿这一神奇的光电材料，急需一种简单普适的，低成本制备方法提高其应用潜能。
发明内容
为了解决上述技术问题，本发明提供一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法。
本发明采用一步法在低温条件下制备金属镧离子掺杂的钙钛矿前驱液，从钙钛矿形核生长等机制出发，在合适的老化时间下，利用热衬底旋涂，温度梯度退火和溶剂退火等合理的优化方式使得钙钛矿从前驱体溶液中结晶出高质量的多晶薄膜。合理控制老化条件有利于保证有机阳离子的稳定与薄膜钙钛矿的相稳定。热衬底有利于旋涂过程中溶剂的挥发加速形核结晶的速率。反溶剂采用高极性氯仿，更有利于快速吸收挥发的溶剂从而降低溶剂蒸气压，加速溶剂挥发，从而使钙钛矿迅速从前驱液中形核。通过常温放置增加DMSO的挥发，防止与铯相关的中间相的形成。采用温度梯度退火：50℃低温常规预退火有利于均匀形核和晶粒生长；70℃下溶剂氛围中后退火，溶剂分子进入晶粒间隙，有利于晶粒的重组和再生长。
利用镧离子掺杂将光生激子转移到钙钛矿材料的复合位点，从本质上提高钙钛矿材料的光致发光量子产率。本发明通过镧掺杂制备了三种不同颜色荧光发射的钙钛矿薄膜，制备的有机无机杂化绿色荧光钙钛矿薄膜光致发光量子产率峰值从17.3％(±0.3％)提高到98％(±0.3％)；由于工艺及激发源功率等原因，未掺杂的蓝光和红光钙钛矿薄膜均未测出PL荧光峰，镧掺杂之后，钙钛矿薄膜荧光效率都具有一定程度的提高。制备的掺镧多晶钙钛矿薄膜XRD图谱显示，其具有钙钛矿α相的特征峰，无杂相的出现。本方法无需繁琐的制备流程和多余的配体注入，掺杂后的前驱液通过低温梯度退火和溶剂氛围退火即可得到高荧光性能钙钛矿薄膜。
本发明通过实验表明：金属镧离子掺杂不同带隙的钙钛矿均有提高光致发光效率的作用，能够基本实验红绿蓝三原色荧光。金属镧离子特有的丰富的能级结构和钙钛矿不同的带隙均具有一定的协同匹配作用。特别对于含有有机阳离子FA的溴基钙钛矿，金属镧离子掺杂到 晶格中容易形成相对多的浅能级缺陷，促使能量更多的从镧系离子的本征能级转移到钙钛矿能级上，使高能激子在钙钛矿带隙处发生跃迁复合从而能提高发光效率。另外，过量的镧系金属转移到晶界处，同时能够有效降低其激子跃迁过程中的非辐射复合途径。
钙钛矿晶体结构通常表达为ABX 3，A位通常指有机阳离子基团或者Cs，B位一般是Pb，X位一般指卤素元素。本发明中，镧原子替代部分铅原子，形成B位掺杂。掺杂及原子替换方式见图1。
梯度退火工艺对晶体内部缺陷等有影响，但对微区形貌并无实质影响。
制备的钙钛矿薄膜由于卤素的不同呈现出不同的颜色与透明度；掺镧的钙钛矿多晶薄膜荧光均具有90％以上的色纯度，详见图8。
本发明提供的技术方案如下：
本发明的目的之一在于提供一种低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，包括以下步骤：
(1)将卤盐M、卤化铅、卤化镧溶于溶剂S中，得到前驱体溶液
(2)将前驱液恒温搅拌反应，再进行老化，得到钙钛矿掺镧前驱液；
(3)将钙钛矿掺镧前驱液过滤后，用匀胶机旋涂于热玻璃衬底上；
(4)旋涂过程中，薄膜变色前滴加反溶剂；
(5)先常温放置，然后预退火，再经后溶剂退火处理即得。
进一步，
所述前驱体溶液根据组分的差异分为天蓝色荧光钙钛矿前驱液、绿色荧光钙钛矿前驱液和红色荧光钙钛矿前驱液；
其中，天蓝色荧光钙钛矿前驱液所用的卤盐M为CsCl，卤化铅为PbBr 2、卤化镧为LaCl 3；
绿色荧光钙钛矿前驱液所用卤盐M为CsBr和FABr，卤化铅为PbBr 2、卤化镧为LaBr 3；
红色荧光钙钛矿前驱液所用卤盐M为MAI，卤化铅为PbI 2、卤化镧为LaI 3。
进一步，所述溶剂S为二甲基甲酰胺和二甲基亚砜的混合溶剂，该混合溶剂有利于前驱体的卤素离子的溶解和反溶剂氯仿对溶剂的萃取。优选的，二甲基甲酰胺和二甲基亚砜的体积比为1:9。
进一步，所述步骤(2)中恒温搅拌反应温度为60℃，反应时间为6h；老化温度为20～28℃，老化时间为10～14h。合理控制老化条件有利于保证有机阳离子的稳定与薄膜钙钛矿的相稳定。
进一步，所述步骤(3)中热玻璃衬底的温度为50℃。热衬底有利于旋涂过程中溶剂的挥发加速形核结晶的速率。
进一步，所述步骤(4)中，滴加反溶剂需在薄膜变色前3～5s的窗口期内，反溶剂为氯仿。氯仿的高极性更有利于快速吸收挥发的溶剂从而降低溶剂蒸气压，加速溶剂挥发，从而使钙钛矿迅速从前驱液中形核。
进一步，所述步骤(5)中常温放置时间为20～30s。
进一步，所述步骤(5)中预退火方法为：50℃下退火1分钟。低温预退火有利于均匀形核和晶粒生长。
进一步，所述步骤(5)中后退火的方法为：70℃～100℃下溶剂S氛围中退火4分钟。溶剂退火条件下，溶剂分子进入晶粒间有利于晶粒的重组和再生长。
本发明的目的之二在于提供利用上述方法制备的高光致发光量子产率的钙钛矿薄膜。
本发明的有益效果：
1)全程采用低温制备，无需配体加入，亦无需高温注入，工艺简单，设备门槛极低，极大降低生产成本，适合工业化生产；
2)所制备的钙钛矿薄膜相比于未掺杂的对照组，其光致发光量子产率显著提升，特别是有机无机杂化溴基绿光荧光，具有很大的应用潜力；
3)所制备的钙钛矿薄膜由很多纳米块组成，并存在大量的孔隙，提高光的耦合出光率；
4)对后期钙钛矿的荧光和白光发射等显示应用和研究具有重要的参考意义；
5)提供一种低温掺镧钙钛矿的制备工艺，具有较大的参考价值。
附图说明
图1是本发明所制备的钙钛矿晶体镧掺杂示意图；
图2是本发明所采用的退火方式及溶剂退火原理示意图；
图3是本发明使用溶剂退火操作示意图；
图4是实施例1及其对比实施例1、3所制备的钙钛矿薄膜的扫描电子显微镜(SEM)图像；其中图4(a)对应对比实施例3，图4(b)对应对比实施例1，图4(c)对应实施例1；
图5分别为实施例2、3及其对比实施例4、5所制备的钙钛矿薄膜的SEM图像，其中图5(a)对应对比实施例5，图5(b)对应实施例3；图5(c)对应对比实施例4，图5(d)对应实施例2；
图6为钙钛矿薄膜X射线衍射(XRD)图，其中图6(a)对应实施例3和对比实施例5，图6(b)对应实施例1和对比实施例3，图6(c)对应实施例2和对比实施例4；
图7是制备的钙钛矿薄膜的吸收和光致发光曲线；其中图7(a)对应实施例3和对比实施例5，图7(b)对应实施例1和对比实施例3，图7(c)对应实施例2和对比实施例4；
图8(a)是所得三种不同颜色荧光的钙钛矿薄膜的光学照片，由上至下依次是实施例2、对比实施例1、实施例1、对比实施例4和实施例3所制备的钙钛矿薄膜；图8(b)为三种镧掺杂薄膜荧光特性在CIE色坐标图上的位置，红绿蓝区分别对应为实施例2、实施例1、实施例3；
图9(a)为实施例1绿色荧光钙钛矿前驱液老化时间与效率关系图；图9(b)是绿色荧光钙钛矿采用不同方式退火的效率统计图；
图10是实施例1所制备的钙钛矿薄膜光致发光量子产率为98％的绿色荧光钙钛矿薄膜和对比实施例3中未掺镧薄膜的光致发光测试曲线，其中365nm的峰为光源峰。
具体实施方式
一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法，包括以下步骤：
(1)衬底准备。在本发明中，采用玻璃衬底，首先将衬底切割成大小适合的尺寸(2cm×2cm)，然后依次用去离子水、丙酮、异丙醇、无水乙醇在超声清洗仪中分别超声清洗15min，然后用氮气吹干，在功率为40W的紫外清洗臭氧机中处理15min得到干净的衬底。
(2)前驱液准备。将卤盐M、卤化铅、卤化镧溶于溶剂S中，得到前驱体溶液；将前驱液恒温搅拌反应，再进行老化，得到钙钛矿掺镧前驱液；
(3)薄膜制备。将钙钛矿掺镧前驱液过滤后，用匀胶机旋涂于热玻璃衬底上；旋涂过程中，薄膜变色前滴加反溶剂；先常温放置，然后预退火，再经后退火处理即得。
进一步，
所述前驱体溶液根据组分的差异分为天蓝色荧光钙钛矿前驱液、绿色荧光钙钛矿前驱液和红色荧光钙钛矿前驱液；
其中，天蓝色荧光钙钛矿前驱液所用的卤盐M为CsCl，卤化铅为PbBr 2、卤化镧为LaCl 3；
绿色荧光钙钛矿前驱液所用卤盐M为CsBr和FABr，卤化铅为PbBr 2、卤化镧为LaBr 3；
红色荧光钙钛矿前驱液所用卤盐M为MAI，卤化铅为PbI 2、卤化镧为LaI 3。
进一步，所述溶剂S为二甲基甲酰胺和二甲基亚砜的混合溶剂。优选的，二甲基甲酰胺 和二甲基亚砜的体积比为1:9。
进一步，所述步骤(2)中恒温搅拌反应温度为60℃，反应时间为6h；老化温度为20～28℃，老化时间为10～14h。
进一步，所述步骤(3)中热玻璃衬底的温度为50℃。
进一步，所述步骤(3)中，滴加反溶剂需在薄膜变色前3～5s的窗口期内，反溶剂为氯仿。
进一步，所述步骤(3)中常温放置时间为20～30s。
进一步，所述步骤(3)中预退火方法为：50℃下退火1分钟。
进一步，所述步骤(3)中后退火的方法为：70℃～100℃下溶剂S氛围中退火4分钟。
所制备的光致发光效率测试。将退火后的玻璃片移至测试手套箱，LQ-100测试系统，利用365nmLED激发源激发钙钛矿薄膜，扣除背底，测试得到光致发光量子产率。
为使本发明更加容易理解，下面将进一步阐述本发明的具体实施例。
实施例1
本实施例提供一种绿色荧光钙钛矿薄膜的制备方法。
按照上述步骤1)中方式清洗玻璃片；将FABr，CsBr，PbBr 2，LaBr 3按摩尔比0.945:0.105:1:0.12溶于1.25ml的DMSO和DMF的体积比为9:1的混合溶剂中，以上称量误差控制在0.1mg以内。
按照上述具体实施方式步骤3)制备钙钛矿薄膜，其中后退火温度为70℃。图2为钙钛矿薄膜制备过程中先采取梯度退火，再进行溶剂退火的示意图，梯度退火防止由于溶剂挥发过快导致的形核不均匀和薄膜裂纹，采用溶剂退火方式使结晶的小颗粒晶体重组再长大，有利于晶体质量的提高。溶剂退火具体操作见图3。
对比实施例1
制备常规退火的掺镧绿色荧光钙钛矿薄膜，制备方法和原料用量同实施例1，区别在于退火为常规退火，即常温放置后于70℃直接退火。
对比实施例2
制备梯度退火的掺镧绿色荧光钙钛矿薄膜，制备方法和原料用量同实施例1，区别在于 不使用溶剂退火，即直接梯度退火。
对比实施例3
制备不掺镧绿色荧光钙钛矿薄膜，制备方法和原料用量同实施例1，区别在于不添加LaBr 3，且采用常规退火的方式，即常温放置后于70℃直接退火。
图4分别为对比实施例3(图4a)，对比实施例1(图4b)以及实施例1(图4c)所制备的钙钛矿薄膜的扫描电子显微镜(SEM)图。由图可见：1)对比未掺杂的钙钛矿，掺镧之后晶粒长大，晶体结晶质量有明显提高；2)通过梯度退火和溶剂氛围后退火，多晶薄膜发生晶粒重组及再生长的现象，结晶质量得到进一步提高。
图6(b)分别为对比实施例3和实施例1钙钛矿薄膜的X射线衍射图，可见1)结晶度提高且并无杂相的出现；2)峰位轻微向大角度移动，来源于掺杂引起的晶格收缩，导致带隙增大，与吸收蓝移相对应。
图7(b)为制备的薄膜的紫外可见吸收曲线光致发光光谱曲线，其中“实施例1Abs”和“对比实施例3Abs”分别为实施例1和对比实施例3所制备的钙钛矿薄膜的紫外可见吸收曲线；“实施例1PL”代表实施例1所制备的钙钛矿薄膜的光致发光光谱曲线。由图可见：1)掺镧之后不影响钙钛矿的α相在540nm附近的光吸收特性；2)通过掺镧，吸收峰和吸收边有略微的蓝移，这和xrd的测试结果相呼应；3)掺镧的薄膜发光峰与其吸收边相对应，体现了钙钛矿薄膜的带边发光特性。
图9(a)为实施例1所制备的钙钛矿薄膜光致发光量子产率随老化时间的变化关系，从图中可以看出，老化时间在10h到14h之间其效率可在95％以上，具有操作重复性；图9(b)为不同退火方式光致发光量子产率统计图，结果表明：对比一步常规70℃退火，通过梯度退火和溶剂退火，可将光致发光量子产率从82.4％进一步提升到98.0％，提升幅度达到将近20％。
图10为光致发光量子产率测试曲线，其中365nm的峰位为激发光源峰，对比实施例3制备的钙钛矿薄膜测试计算PLQY峰值为17.3％，实施例1制备的钙钛矿薄膜测试计算PLQY峰值为98.0％，可见掺杂镧以后对荧光强度有很大的提升。
实施例2
本实施例提供一种红色荧光钙钛矿薄膜的制备方法。
按照具体实施方式步骤1)中方式清洗玻璃片；称取MAI、PbI 2、DMSO、LaI 3按摩尔比 1:1:1:0.1加入到1ml DMF中，以上称量误差控制在0.1mg以内。按照上述具体实施方式步骤3)中方法制备钙钛矿薄膜，其中后退火的温度需设置为100℃，其他条件不变。
对比实施例4
制备红色荧光钙钛矿薄膜，制备方法和原料用料同实施例2，区别在于不添加LaI 3。
图5c为对比实施例4所制备的钙钛矿薄膜的SEM图；图5d为实施例2所制备的钙钛矿薄膜的SEM图。对比可知：1)对比未掺杂的钙钛矿，掺镧之后晶粒长大，具有一定的分散性，晶体结晶质量有明显提高；2)通过梯度退火和溶剂氛围后退火，多晶薄膜发生晶粒重组及再生长的现象。
图6(c)为制备的实施例2和对比实施例4所制备的钙钛矿薄膜的X射线衍射图，可见1)结晶度提高且并无杂相的出现；2)峰位轻微向大角度移动，来源于掺杂引起的晶格收缩，导致带隙增大，与吸收蓝移相对应。
图7(c)为制备的薄膜的紫外可见吸收曲线光致发光光谱曲线，其中“实施例2Abs”、“对比实施例4Abs”和“实施例2PL”类似于图7(b)中的“实施例1Abs”、“对比实施例3Abs”和“实施例1PL”。由图可见：1)掺镧之后不影响钙钛矿的α相在780nm附近的光吸收特性；2)通过掺镧，吸收峰和吸收边有略微的蓝移，这和xrd的测试结果相呼应；3)掺镧的发光峰与薄膜的吸收边相对应，体现了钙钛矿薄膜的带边发光特性。
实施例3
本实施例提供一种天蓝色荧光钙钛矿薄膜的制备方法。
按照具体实施方式步骤1)中方式清洗玻璃片；称取CsCl、PbBr 2、LaCl 3按摩尔比1:1:0.05溶于4ml的DMSO和DMF的体积比为9:1的混合溶剂中，以上称量误差控制在0.1mg以内。按照前述具体实施方式步骤3)中方法制备钙钛矿薄膜，其中后退火温度为70℃，其他条件不变。
对比实施例5
制备不掺镧天蓝色荧光钙钛矿薄膜，制备方法同实施例3，区别在于不添加LaCl 3。
图5a为对比实施例5所制备的钙钛矿薄膜的SEM图；图5b为实施例3所制备的钙钛矿薄膜的SEM图。从图中可以看出：1)对比未掺杂的钙钛矿，掺镧之后晶粒有一定程度的长大，但是薄膜更加不连续，这与氯元素的溶解性有关，2)通过梯度退火和溶剂氛围后退火，多晶薄膜同样发生晶粒重组及再生长的现象。
图6(a)为实施例3和对比实施例5所制备的钙钛矿薄膜的X射线衍射图，可见：1)常规前驱液对钙钛矿的溶解度不高导致的薄膜覆盖率不好，导致整体结晶性能不好；1)特征峰有略微的向大角度移动，同样来源于掺杂引起的晶格收缩，导致带隙增大，与吸收蓝移相对应。
图7(a)为制备的薄膜的紫外可见吸收曲线光致发光光谱曲线，其中“实施例3Abs”、“对比实施例5Abs”和“实施例3PL”类似于图7(b)中的“实施例1Abs”、“对比实施例3Abs”和“实施例1PL”。由图可见：1)掺镧之后不影响钙钛矿的α相在480nm附近的光吸收特性；2)通过掺镧，吸收峰和吸收边有略微的蓝移，这和xrd的测试结果相呼应；3)掺镧的发光峰与薄膜的吸收边相对应，体现了钙钛矿薄膜的带边发光特性。
以上所述，仅为本发明较佳的具体实施方式，但本发明保护的范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内所做的任何修改，等同替换和改进等，均应包含在发明的保护范围之内。

Claims (10)

  1. 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于，包括以下步骤：
    (1)将卤盐M、卤化铅、卤化镧溶于溶剂S中，得到前驱体溶液；
    (2)将前驱液恒温搅拌反应，再进行老化，得到钙钛矿掺镧前驱液；
    (3)将钙钛矿掺镧前驱液过滤后，用匀胶机旋涂于热玻璃衬底上；
    (4)旋涂完毕后，薄膜变色前滴加反溶剂；
    (5)先常温放置，然后预退火，再经后退火即得。
  2. 根据权利要求1所述的低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于：所述前驱体溶液根据组分的差异分为天蓝色荧光钙钛矿前驱液、绿色荧光钙钛矿前驱液和红色荧光钙钛矿前驱液；
    其中，天蓝色荧光钙钛矿前驱液所用的卤盐M为CsCl，卤化铅为PbBr 2、卤化镧为LaCl 3；
    绿色荧光钙钛矿前驱液所用卤盐M为CsBr和FABr，卤化铅为PbBr 2、卤化镧为LaBr 3；
    红色荧光钙钛矿前驱液所用卤盐M为MAI，卤化铅为PbI 2、卤化镧为LaI 3。
  3. 根据权利要求1所述的低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于：所述溶剂S为二甲基甲酰胺(DMF)和二甲基亚砜(DMSO)的混合溶剂。
  4. 根据权利要求1所述的低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于：所述步骤(2)中恒温搅拌反应温度为60℃，反应时间为6h；老化温度为20～28℃，老化时间为10～14h。
  5. 根据权利要求1所述的低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于：所述步骤(3)中热玻璃衬底的温度为50℃。
  6. 根据权利要求1所述的低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于：所述步骤(4)中，滴加反溶剂时间需在薄膜变色前3～5s的窗口期内，反溶剂为氯仿。
  7. 根据权利要求1所述的低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于：所述步骤(5)中常温放置时间为20s～30s。
  8. 根据权利要求1所述的低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于：所述步骤(5)中预退火方法为：50℃下常规退火1分钟。
  9. 根据权利要求1所述的低温掺杂、高光致发光量子产率的钙钛矿薄膜的制备方法，其特征在于：所述步骤(5)中后退火的方法为：70℃～100℃下溶剂S氛围中退火4分钟。
  10. 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜，其特征在于：采用权利要求1～ 9任一项所述的方法制备。
PCT/CN2021/073527 2020-04-24 2021-01-25 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法 WO2021212942A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010330762.3A CN111477746B (zh) 2020-04-24 2020-04-24 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法
CN202010330762.3 2020-04-24

Publications (1)

Publication Number Publication Date
WO2021212942A1 true WO2021212942A1 (zh) 2021-10-28

Family

ID=71764051

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/073527 WO2021212942A1 (zh) 2020-04-24 2021-01-25 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法

Country Status (2)

Country Link
CN (1) CN111477746B (zh)
WO (1) WO2021212942A1 (zh)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114188487A (zh) * 2021-12-10 2022-03-15 中国地质大学（北京） 利用含乙酸铵的反溶剂制备钙钛矿太阳能电池的方法
CN115028197A (zh) * 2022-08-12 2022-09-09 南昌大学 一种低频超高介电常数材料及其制备方法
CN115851273A (zh) * 2022-12-16 2023-03-28 吉林大学 一种稀土掺杂钙钛矿纳米晶合成方法
CN115959836A (zh) * 2022-12-28 2023-04-14 吉林大学 一种无机钙钛矿薄膜及其制备方法、应用
CN116083085A (zh) * 2022-12-02 2023-05-09 南通昇纳光学技术有限公司 一种钙钛矿量子点及其制备方法
CN116282933A (zh) * 2023-03-22 2023-06-23 昆明理工大学 一种高透明铅基钙钛矿微晶玻璃的制备方法与应用
CN116759022A (zh) * 2023-05-26 2023-09-15 广东工业大学 一种调控稀土离子掺杂激光玻璃发光峰位的方法
CN117881257A (zh) * 2024-03-11 2024-04-12 浙江省白马湖实验室有限公司 一种高效率碳电极钙钛矿太阳能电池的制备方法

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111477746B (zh) * 2020-04-24 2022-03-04 武汉大学 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法
CN112054126B (zh) * 2020-08-28 2021-10-29 河南大学 一种铯锡碘薄膜、其制备方法及应用
CN113192821A (zh) * 2021-04-20 2021-07-30 电子科技大学 一种全无机CsPbI3钙钛矿薄膜的制备方法及其应用
CN113193128A (zh) * 2021-05-24 2021-07-30 电子科技大学 一种具有界面修饰层的钙钛矿太阳能电池及其制备方法
CN113506858B (zh) * 2021-06-01 2022-10-25 武汉大学 一种镉掺杂钙钛矿发光二极管及其制备方法
CN115536056B (zh) * 2022-09-29 2024-03-01 无锡极电光能科技有限公司 一种钙钛矿量子点及其合成方法和用途
CN115710502B (zh) * 2022-11-19 2024-01-02 深圳先进技术研究院 Yb3+掺杂CsPbBr3PMSCs及其制备方法和应用
CN116004229B (zh) * 2023-01-04 2023-12-05 吉林大学 一种叶绿素修饰的CsPbCl3：Yb3+钙钛矿薄膜及其制备方法和应用

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107275492A (zh) * 2017-05-19 2017-10-20 北京科技大学 引入非溶质基溴化物添加剂制备混合卤素钙钛矿的方法
CN108602756A (zh) * 2016-02-19 2018-09-28 住友化学株式会社 化合物及发光材料
CN108690619A (zh) * 2017-04-05 2018-10-23 Tcl集团股份有限公司 稀土金属掺杂钙钛矿量子点的制备方法
CN111477746A (zh) * 2020-04-24 2020-07-31 武汉大学 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11078413B2 (en) * 2016-08-04 2021-08-03 Florida State University Research Foundation, Inc. Organic-inorganic hybrid perovskites, devices, and methods
US11549056B2 (en) * 2016-08-26 2023-01-10 King Abdullah University Of Science And Technology Compositions and methods relating to luminescent structures
CN107785495A (zh) * 2017-09-18 2018-03-09 南昌航空大学 无铅钙钛矿量子点及其柔性发光二极管的制备方法
CN108329912A (zh) * 2018-01-18 2018-07-27 华中科技大学 一种提高非铅卤素钙钛矿材料的荧光产率和稳定性的方法
CN109370563A (zh) * 2018-10-17 2019-02-22 广西大学 一种卤铅铯钙钛矿荧光材料及其制备方法
CN109504365A (zh) * 2018-12-31 2019-03-22 北京化工大学 一种可见光区连续调节发射波长的高稳定性复合发光材料及其制备方法
CN109810703A (zh) * 2019-03-04 2019-05-28 上海应用技术大学 一种CsPbBr3量子点的室温制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108602756A (zh) * 2016-02-19 2018-09-28 住友化学株式会社 化合物及发光材料
CN108690619A (zh) * 2017-04-05 2018-10-23 Tcl集团股份有限公司 稀土金属掺杂钙钛矿量子点的制备方法
CN107275492A (zh) * 2017-05-19 2017-10-20 北京科技大学 引入非溶质基溴化物添加剂制备混合卤素钙钛矿的方法
CN111477746A (zh) * 2020-04-24 2020-07-31 武汉大学 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114188487A (zh) * 2021-12-10 2022-03-15 中国地质大学（北京） 利用含乙酸铵的反溶剂制备钙钛矿太阳能电池的方法
CN115028197A (zh) * 2022-08-12 2022-09-09 南昌大学 一种低频超高介电常数材料及其制备方法
CN116083085A (zh) * 2022-12-02 2023-05-09 南通昇纳光学技术有限公司 一种钙钛矿量子点及其制备方法
CN115851273A (zh) * 2022-12-16 2023-03-28 吉林大学 一种稀土掺杂钙钛矿纳米晶合成方法
CN115851273B (zh) * 2022-12-16 2023-12-15 吉林大学 一种稀土掺杂钙钛矿纳米晶合成方法
CN115959836A (zh) * 2022-12-28 2023-04-14 吉林大学 一种无机钙钛矿薄膜及其制备方法、应用
CN116282933A (zh) * 2023-03-22 2023-06-23 昆明理工大学 一种高透明铅基钙钛矿微晶玻璃的制备方法与应用
CN116759022A (zh) * 2023-05-26 2023-09-15 广东工业大学 一种调控稀土离子掺杂激光玻璃发光峰位的方法
CN116759022B (zh) * 2023-05-26 2024-02-02 广东工业大学 一种调控稀土离子掺杂激光玻璃发光峰位的方法
CN117881257A (zh) * 2024-03-11 2024-04-12 浙江省白马湖实验室有限公司 一种高效率碳电极钙钛矿太阳能电池的制备方法
CN117881257B (zh) * 2024-03-11 2024-05-28 浙江省白马湖实验室有限公司 一种高效率碳电极钙钛矿太阳能电池的制备方法

Also Published As

Publication number Publication date
CN111477746B (zh) 2022-03-04
CN111477746A (zh) 2020-07-31

Similar Documents

Publication Publication Date Title
WO2021212942A1 (zh) 一种低温掺杂、高光致发光量子产率的钙钛矿薄膜及其制备方法
Sun et al. 0D perovskites: unique properties, synthesis, and their applications
US11046589B2 (en) Multi-element perovskite material as well as preparation and luminescent application thereof
Kumar et al. Effect of annealing on the structural, morphological and photoluminescence properties of ZnO thin films prepared by spin coating
Chen et al. Cation-doping matters in caesium lead halide perovskite nanocrystals: from physicochemical fundamentals to optoelectronic applications
Garskaite et al. Luminescent properties of rare earth (Er, Yb) doped yttrium aluminium garnet thin films and bulk samples synthesised by an aqueous sol–gel technique
US8066908B2 (en) Production of light from sol-gel derived thin films made with lanthanide doped nanoparticles, and preparation thereof
Bandi et al. Host sensitized novel red phosphor CaZrSi2O7: Eu3+ for near UV and blue LED-based white LEDs
Sun et al. Rare earth doping in perovskite luminescent nanocrystals and photoelectric devices
Jia et al. Synthesis of NaYF 4: Yb–Tm thin film with strong NIR photon up-conversion photoluminescence using electro-deposition method
Pang et al. Luminescent properties of rare-earth-doped CaWO4 phosphor films prepared by the Pechini sol–gel process
Shah et al. Recent advances and emerging trends of rare-earth-ion doped spectral conversion nanomaterials in perovskite solar cells
Jin et al. Low-dimensional phase suppression and defect passivation of quasi-2D perovskites for efficient electroluminescence and low-threshold amplified spontaneous emission
Zi et al. Highly efficient and stable Cs 2 TeCl 6: Cr 3+ perovskite microcrystals for white light emitting diodes
Khichar et al. Introducing dual excitation and tunable dual emission in ZnO through selective lanthanide (Er 3+/Ho 3+) doping
Samanta et al. Recent progress in lanthanide-based metal halide perovskites: Synthesis, properties, and applications
Patil et al. Understanding the synergistic influence of the propylammonium bromide additive and erbium-doped CsPbI 2 Br for highly stable inorganic perovskite solar cells
Zhou et al. A and B sites dual substitution by Na+ and Cu2+ co-doping in CsPbBr3 quantum dots to achieve bright and stable blue light emitting diodes
Kim et al. Properties of Yb-added ZnO (Yb: ZnO) films as an energy-conversion layer on polycrystalline silicon solar cells
CN114752385B (zh) 一种Gd3+掺杂微米晶体材料及其制备方法和应用
Li et al. Vitamin needed: Lanthanides in optoelectronic applications of metal halide perovskites
Fujihara et al. Phase‐Selective Pyrolysis and Pr3+ Luminescence in a YF3–Y2O3 System from a Single‐Source Precursor
Chao et al. Annealing effects on the properties of Nd containing ZnO nanoparticles prepared by sol–gel process
JP5739203B2 (ja) 酸化アルミニウム蛍光体の製造方法
Nanai et al. Luminescence properties of rare-earth-doped thiosilicate phosphors on silicon substrate

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21792086

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21792086

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205 DATED 05/06/2023)

122 Ep: pct application non-entry in european phase

Ref document number: 21792086

Country of ref document: EP

Kind code of ref document: A1