A flexible laser based on DJ quasi-2D perovskite material and its applications

Abstract

This invention discloses a flexible laser based on D-J quasi-2D perovskite material and its application, comprising: a flexible substrate; a two-photon 3D-printed polymer microcavity disposed on the flexible substrate; and a D-J quasi-2D perovskite gain dielectric film covering the polymer microcavity. The film is prepared by the following method: dissolving PbBr2, CsBr, PDABr, and HDABr in DMSO to obtain a 0.4M perovskite precursor solution; dissolving tributylphosphine oxide in ethyl acetate to obtain an EA@TBPO solution; sequentially ultrasonically cleaning a PET substrate with deionized water, acetone, and isopropanol, followed by nitrogen drying and plasma treatment; filtering the precursor solution and spin-coating it onto the PET substrate, adding the EA@TBPO solution dropwise during spin-coating; and low-temperature annealing to form a crystalline D-J phase perovskite film. This invention provides a laser with high stability, low power consumption, and resistance to mechanical stress.

Description

Technical Field

[0001] This invention belongs to the field of laser technology, specifically relating to a flexible laser based on DJ quasi-2D perovskite material and its applications. Background Technology

[0002] Traditional lasers are mostly based on rigid substrates, such as silicon wafers and glass. These rigid lasers have significant limitations in application scenarios and cannot meet the demands of emerging fields such as wearable devices and flexible electronics for flexible and bendable devices. In recent years, flexible lasers have become a research hotspot. By using flexible substrates instead of rigid substrates, they have provided new possibilities for expanding the applications of lasers.

[0003] In the research of flexible lasers, material selection and microcavity fabrication are crucial. Perovskite materials, due to their excellent optical properties such as high fluorescence quantum yield, wide spectral tunability, and high carrier mobility, are widely used in optoelectronic devices. However, current flexible lasers based on perovskite materials still face some challenges. For example, perovskite materials have poor stability, are prone to degradation under environmental factors such as humidity and oxygen, and are easily affected by stress during bending, leading to a decrease in the luminous efficiency of the perovskite emissive layer. Among them, Dion-Jacobson quasi-2D perovskites show great potential in optoelectronic devices due to their unique crystal structure and optical properties. Dion-Jacobson quasi-2D perovskites exhibit enhanced structural robustness and more efficient charge transfer because diammonium cations electrostatically connect adjacent inorganic layers without forming van der Waals gaps. Simultaneously, this layered structure with alternating organic and inorganic layers endows the material with a certain degree of mechanical flexibility. Currently, the mainstream method for preparing DJ-type quasi-2D perovskite laser gain medium films is the overheating method. This method, which uses high temperature and high pressure, is not suitable for large-scale manufacturing or for integration with flexible substrates.

[0004] Therefore, how to achieve low-temperature preparation of highly stable DJ phase perovskite thin films and efficiently couple them with flexible microcavities, and provide a low-threshold, bend-resistant flexible perovskite laser, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The first objective of this invention is to provide a flexible laser based on DJ quasi-2D perovskite material, addressing the problems in the prior art.

[0006] Therefore, the above-mentioned objectives of the present invention are achieved through the following technical solutions:

[0007] A flexible laser based on DJ quasi-2D perovskite material, comprising:

[0008] Flexible substrate;

[0009] Two-photon 3D printed polymer microcavities disposed on the flexible substrate;

[0010] A DJ quasi-2D perovskite gain dielectric film covering the polymer microcavity is prepared by the following method:

[0011] Step S1, Preparation of precursor solution: PbBr2, CsBr, PDABr and HDABr are dissolved in DMSO to obtain a perovskite precursor solution with a concentration of 0.2M-1.0mol / ml;

[0012] Step S2, preparation of antisolvent: Dissolve tri-n-butylphosphine oxide in ethyl acetate at a concentration of 0.02 mol / ml to obtain EA@TBPO solution;

[0013] Step S3, Substrate treatment: The PET substrate is ultrasonically cleaned with deionized water, acetone and isopropanol in sequence, dried with nitrogen and then subjected to plasma treatment.

[0014] Step S4, Thin film deposition: After filtering the precursor solution from step S1, spin-coat it onto a PET substrate, and add EA@TBPO solution dropwise during spin-coating;

[0015] Step S5, Low-temperature annealing: The spin-coated sample is annealed at a low temperature to form a crystallized DJ phase perovskite film.

[0016] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0017] As a preferred technical solution of the present invention: the polymer microcavity is 3D printed in a circular shape with a size in the micrometer range using NanoscribeIP-dip photoresist.

[0018] As a preferred embodiment of the present invention, the flexible substrate is polyethylene terephthalate.

[0019] As a preferred technical solution of the present invention: In step S1, PbBr2, CsBr, PDABr and HDABr are dissolved in DMSO in a molar ratio of (8~16): (8~16): (1~2): (1~2).

[0020] As a preferred technical solution of the present invention: in step S1, PbBr2, CsBr, PDABr and HDABr are in a molar ratio of 16:16:1:1, wherein PDABr and HDABr organic ammonium ions account for 5.88% of the total cations.

[0021] As a preferred technical solution of the present invention: TBPO in the EA@TBPO solution and Pb in the perovskite precursor solution 2+ The molar ratio is 1:20.

[0022] The second objective of this invention is to provide an application of a flexible laser based on DJ quasi-2D perovskite material, addressing the problems in the prior art.

[0023] Therefore, the above-mentioned objectives of the present invention are achieved through the following technical solutions:

[0024] The application of the flexible laser based on DJ quasi-2D perovskite material is described above. This laser is used in flexible optoelectronic systems to achieve WGM laser output under 400nm femtosecond laser pumping, with a threshold voltage ≤ 2.16 μJ / cm². 2 Net modal gain ≥1704cm at 10 times the threshold -1 .

[0025] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0026] As a preferred embodiment of the present invention, the flexible optoelectronic system includes a wearable biosensor, a flexible display backplane or a micro spectral analysis module, and the laser is integrated into the system as a low-power light source.

[0027] Compared with existing technologies, the flexible laser based on DJ quasi-2D perovskite material and its application of the present invention have the following beneficial effects: In the present invention, the defect passivation effect of TBPO additive in ethyl acetate antisolvent enables the preparation of highly crystalline DJ phase perovskite thin films at low temperatures, solving the problem of damage to flexible substrates caused by traditional high temperature and high pressure processes; the introduction of TBPO additive, through the P=O bond in TBPO and Pb 2+ The vacancy and the P=O bond form hydrogen bonds with the NH bond in the DJ organic macromolecule, which solves the contradiction between stability and flexibility, improves the crystallinity and optical properties of the film, and further enhances the stability of the DJ quasi-two-dimensional perovskite material; by changing the size of the microcavity in two-photon 3D printing, this invention can achieve laser mode selection and realize multi-mode or single-mode laser output.

[0028] This invention fabricates a high-performance flexible laser by using an ultra-stable DJ-phase perovskite thin film gain medium and combining a polymer microcavity with a flexible substrate using 3D printing technology. By using two-photon 3D printing of the microcavity, a whispering-gallery mode (WGM) laser is realized. The flexible laser of this invention exhibits excellent laser performance and strong mechanical toughness, and has great potential for applications in wearable electronics, optical communication, and robotic systems. Attached Figure Description

[0029] Figure 1 Figure (a) shows the SEM image before TBPO processing. Figure 1Figure (b) shows the SEM image after TBPO processing. Figure 1 Figure (c) shows the AFM image before TBPO processing. Figure 1 Figure (d) in the figure is the AFM image after TBPO processing;

[0030] Figure 2 Figure (a) shows a comparison of the original fluorescence spectrum before TBPO treatment and the fluorescence spectrum after TBPO treatment. Figure 2 Figure (b) shows the fluorescence spectrum of the original sample before TBPO treatment. Figure 2 Figure (c) shows the fluorescence spectrum of the sample after TBPO treatment. Figure 2 Figure (d) shows the pump intensity-dependent emission spectrum of the film before TBPO treatment, as well as the relationship between PL intensity and FWHM and pump density. Figure 2 Figure (e) shows the pump intensity-dependent emission spectrum of the TBPO-treated film and the relationship between PL intensity and FWHM and pump density. Figure 2 Figure (f) shows the optical gain parameters before and after TBPO processing;

[0031] Figure 3 Figure (a) shows ring structures of different sizes fabricated on a 100μm×100μm square flexible substrate. Figure 3 Figure (b) shows lasers with ring structures of different sizes;

[0032] Figure 4 Figure (a) shows the pump density-dependent laser spectrum in a 3 μm ring. Figure 4 In the middle, Figure 4 Figure (b) shows the relationship between laser intensity and FWHM and pump density. Figure 4 Figure (c) shows the stability test performed at 1.5 times the threshold intensity. Figure 4 Figure (d) shows fluorescence images of (I) and (II) obtained by first-order coherence measurements using a Michelson interferometer at different delay times below (III) and above (IV) thresholds, illustrating the transition from spontaneous emission to WGM laser.

[0033] Figure 5 Figure (a) shows images of a flexible laser at different degrees of bending. Figure 5 Figure (b) shows the laser intensity and quality factor tests under different degrees of curvature; Figure 5 Figure (c) shows the mechanical durability test of the flexible perovskite laser, with a bending degree of 8 mm. Detailed Implementation

[0034] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] This invention aims to provide an ultra-stable DJ-phase perovskite flexible laser that combines a two-photon 3D-printed microcavity. By optimizing material properties and flexible microcavity fabrication, the advantages of the DJ-phase perovskite gain medium are fully utilized on a flexible substrate, thereby improving the laser's luminous efficiency, stability, and overall performance to meet the needs of different application scenarios.

[0036] In this application, DJ specifically refers to Dion-Jacobson.

[0037] This invention utilizes the optical and material properties of the quasi-2D perovskite thin film gain medium by using the additive tri-n-butylphosphine oxide (TBPO) to combine it with a 3D-printed polymer microcavity to achieve the fabrication of a flexible perovskite laser device in WGM mode.

[0038] The specific inventive points are as follows:

[0039] 1. To address the challenge of large-scale fabrication of high-performance DJ-type perovskite gain media, TBPO additive was introduced. This allows the P=O bonds in TBPO to interact with Pb... 2+ The vacancies and the P=O bonds forming hydrogen bonds with the NH bonds in the DJ organic macromolecules improve the crystallinity and optical properties of the film, further enhancing the stability of the DJ quasi-two-dimensional perovskite material.

[0040] 2. In order to achieve bonding with flexible substrates at low temperatures, this invention adopts a full solution method. By introducing TBPO into ethyl acetate (EA) antisolvent, it acts as a surface defect passivator. During the spin coating process, EA@TBPO solution is added dropwise and annealed at low temperature (70°C). This does not cause damage to the flexible substrate due to high temperature, thus achieving a perfect match with the flexible substrate.

[0041] 3. To improve the combination of 3D printed polymer microcavities and flexible substrates (polyethylene terephthalate), different sizes of rings were fabricated by changing the two-photon printing power. This ring structure has good interface matching with the DJ-phase quasi-two-dimensional perovskite thin film gain medium, and a high-performance laser gain medium was grown in the ring.

[0042] 4. Laser threshold as low as 2.16 μJ / cm based on flexible substrate. 2 At a threshold of 10, the net modal gain can reach 1704 cm⁻¹. -1 This is currently the best material among DJ phase perovskite gain media and the most powerful flexible laser among all flexible perovskite laser devices.

[0043] 5. In this invention, nanoscrible IP-dip is used as the photoresist for two-photon 3D printing, and the 3D printed circular microcavity structure is at the micrometer level.

[0044] 6. By changing the size of the microcavity in two-photon 3D printing, the laser mode can be selected, enabling multi-mode or single-mode laser output.

[0045] 7. By pumping the intracavity laser gain medium with a 1kHz 400nm femtosecond light, low-threshold high-gain laser emission can be achieved. Stable lasing for more than 12 hours can be achieved at twice the threshold.

[0046] 8. The flexible laser can still maintain high-efficiency light emission under different bending degrees, and after 3,000 bending experiments, it can still achieve high-efficiency laser output, demonstrating excellent mechanical toughness and stability.

[0047] This invention discloses a flexible laser based on DJ quasi-2D perovskite material and its applications. It utilizes an ultra-stable DJ-phase perovskite thin-film gain medium and employs 3D printing technology to combine a polymer microcavity with a flexible substrate to fabricate a high-performance flexible laser. This invention achieves whispering-gallery mode (WGM) laser performance through two-photon 3D printing of the microcavity. This flexible laser exhibits excellent laser performance and strong mechanical toughness, highlighting its enormous potential in applications such as wearable electronics, optical communications, and robotic systems. The DJ quasi-2D perovskite material-based flexible laser of this invention is particularly suitable for applications requiring special flexibility and thinness, such as wearable devices, flexible displays, and biomedical detection.

[0048] Example 1

[0049] Experimental materials: lead bromide (PbBr2), cesium bromide (CsBr), 1,3-diaminopropane dihydrobromide (PDABr), 1,6-hexanediamine hydrobromide (HDABr), dimethyl sulfoxide (DMSO), ethyl acetate (EA), and tri-n-butylphosphine oxide (TBPO).

[0050] Experimental methods:

[0051] Precursor solution preparation: Dissolve 0.4 mmol of PbBr2 (146.8 mg), 0.4 mmol of CsBr (84.8 mg), 0.025 mmol of PDABr (5.9 mg), and 0.025 mmol of HDABr (6.9 mg) in 1 ml of DMSO and stir for 2 hours until dissolved.

[0052] EA@TBPO solvent preparation: Dissolve 0.02 mmol TBPO (4.36 mg) in 1 ml EA solution and stir for 1 hour until dissolved.

[0053] Substrate preparation: PET substrates are used to prepare perovskite thin films. First, the PET substrate is ultrasonically treated in deionized water, acetone, and isopropanol for 5 minutes. Then, in this invention, the PET substrate is dried using a nitrogen stream. The cleaned substrate is then treated with plasma for 15 minutes.

[0054] Laser fabrication: The precursor solution and EA@TBPO solution were filtered through a poly(hexamethylene adipamide) membrane filter. 75 μL of the precursor solution was dropped onto a flexible substrate and spin-coated for 60 s. At 30 s, 200 μL of EA@TBPO solution was dropped onto the substrate and then transferred to a heating stage for annealing at 80 °C for 10 min.

[0055] Control group: The precursor solution and EA solution were filtered through a poly(hexamethylene adipamide) membrane filter. 75 μL of the precursor solution was dropped onto a flexible substrate and spin-coated for 60 s. 200 μL of EA solution was dropped at 30 s, and then transferred to a heating stage for annealing at 80 °C for 10 min.

[0056] Experimental results:

[0057] Figure 1 Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were performed on the control group and the DJ quasi-2D perovskite film after TBPO treatment. It can be seen that the perovskite film surface after TBPO treatment has dense grains and a smooth film surface.

[0058] Figure 2 Fluorescence (PL) and fluorescence lifetime (TRPL) of the film after TBPO treatment. The fluorescence of the film was enhanced and the fluorescence lifetime was prolonged after TBPO treatment, indicating that defects in the perovskite film were significantly suppressed.

[0059] Figure 3 In this invention, flexible laser devices are fabricated by constructing whispering-gallery mode (WGM) cavities on a polyethylene terephthalate (PET) substrate using two-photon 3D printing technology. These WGM cavities exhibit excellent mechanical strength. Figure 3 As shown in Figure (a), in this invention, ring structures of different sizes (6μm, 5μm, 4μm, 3μm) were fabricated on a 100μm × 100μm square flexible substrate, and perovskite films were deposited into the rings by spin coating. Figure 3 As shown in Figure (b), by reducing the microcavity size (5μm~3μm), the number of WGM modes in the gain region can be reduced to a single mode, thereby realizing single-mode laser.

[0060] Figure 4Under environmental conditions, with single-photon excitation (using a 400nm femtosecond laser pulse), and through a strip-pumped configuration, the emission spectrum evolves from spontaneous emission to amplified spontaneous emission (ASE). For example... Figure 4 Figure (a) shows the emission spectra of the pristine perovskite film under different excitation intensities. At low pump densities, a broad spontaneous emission spectrum centered at 523 nm is observed, with a maximum free wave size (FWHM) of approximately 26 nm. With increasing pump density, a distinct narrow emission peak appears at 539 nm, and the FWHM decreases by 6 nm, indicating the onset of amplified spontaneous emission (ASE). Figure 4 Figure (b) shows the relationship between PL intensity and FWHM and pump density, indicating an ASE threshold of 11.6 μJ / cm. 2 In contrast, TBPO-treated perovskite films exhibit ASE behavior centered at 541 nm, such as... Figure 4 As shown in (c) above, the ASE threshold of the quasi-2D perovskite film was reduced to 3.2 μJ / cm by TBPO treatment. 2 ,like Figure 4 As shown in Figure (d), the reduction is nearly 70%.

[0061] Figure 5 :like Figure 5 As shown in Figure (a), to evaluate the mechanical reliability of the flexible laser under stress, the present invention measured the laser threshold and quality factor at different curvatures (from 8 mm to 2 mm), such as... Figure 5 As shown in Figure (b) of the document. Figure 5 As shown in Figure (b), under slight bending (length 10⁻⁸ mm), the threshold of the flexible laser decreases from 2.16 μJ / cm. 2 Increased to 2.82 μJ / cm 2 The quality factor decreased to 2557. However, under severe bending (length 6-2 mm), the threshold value increased sharply to 8.88 μJ / cm. 2 The quality factor dropped to 1353. This nonlinear degradation may stem from structural changes caused by excessive mechanical deformation within the microcavity. The flexible laser retained >80% of its initial intensity after 3,000 bending cycles, such as... Figure 5 As shown in Figure (c), it exhibits excellent robustness under mechanical stress.

[0062] In the prior art, the lowest threshold for gain media in quasi-2D DJ lasers is 5.5 μJ / cm. 2 The quasi-2D DJ laser gain medium ASE fabricated using the method of this invention has a minimum threshold of 3.2 μJ / cm. 2 The minimum threshold for single-mode laser is 2.16 μJ / cm. 2Compared to ordinary perovskite gain media, it exhibits an extremely low threshold and high stability.

[0063] The above specific embodiments are used to explain and illustrate the present invention, and are only preferred embodiments of the present invention, not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A flexible laser based on DJ quasi-2D perovskite material, characterized in that, include: Flexible substrate; Two-photon 3D printed polymer microcavities are disposed on the flexible substrate. The microcavities are micron-scale circular structures and are printed using Nanoscribe IP-dip photoresist. A DJ quasi-2D perovskite gain dielectric film covering the polymer microcavity is prepared by the following method: Step S1, Preparation of precursor solution: PbBr2, CsBr, PDABr and HDABr are dissolved in DMSO to obtain a perovskite precursor solution with a concentration of 0.2M-1.0mol / ml, wherein PbBr2, CsBr, PDABr and HDABr are in a molar ratio of 16:16:1:

1. Step S2, preparation of antisolvent: Dissolve tri-n-butylphosphine oxide in ethyl acetate at a concentration of 0.02 mol / ml to obtain EA@TBPO solution; Step S3, Substrate treatment: The PET substrate is ultrasonically cleaned with deionized water, acetone and isopropanol in sequence, dried with nitrogen and then subjected to plasma treatment. Step S4, Thin Film Deposition: After filtering the precursor solution from Step S1, spin-coat it onto a PET substrate. During spin-coating, add EA@TBPO solution dropwise, wherein the TBPO in the EA@TBPO solution reacts with the Pb in the perovskite precursor solution. 2+ The molar ratio is 1:20; Step S5, Low-temperature annealing: The spin-coated sample is annealed at a low temperature to form a crystallized DJ-phase perovskite film. The laser achieves WGM laser output under 400nm femtosecond laser pumping, with a threshold ≤2.16μJ / cm. 2 Net modal gain ≥1704cm at 10 times the threshold -1 .

2. The flexible laser based on DJ quasi-2D perovskite material as described in claim 1, characterized in that: The flexible substrate is polyethylene terephthalate.

3. The flexible laser based on DJ quasi-2D perovskite material as described in claim 1, characterized in that: In step S1, PbBr2, CsBr, PDABr and HDABr are dissolved in DMSO in a molar ratio of (8~16): (8~16): (1~2): (1~2).

4. The flexible laser based on DJ quasi-2D perovskite material as described in claim 1, characterized in that: In step S1, PDABr and HDABr organic ammonium ions account for 5.88% of the total cations.

5. The application of the flexible laser based on DJ quasi-2D perovskite material as described in any one of claims 1-4, characterized in that: The laser is applied to a flexible optoelectronic system, which includes a wearable biosensor, a flexible display backplane, or a miniature spectral analysis module. The laser is integrated into the system as a low-power light source.

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