Application of hybrid halide to nonlinear optical effect enhancement in high-pressure environment

Abstract

The invention discloses application of hybrid halide to nonlinear optical effect enhancement in a high-pressure environment. The application comprises the following steps: (1) synthesizing the hybrid halide; and (2) hydrostatic pressure is applied to the hybrid halide in the diamond anvil cell, so that the nonlinear optical response of the hybrid halide is improved. Physical pressure is selected as a regulation and control means, compared with chemical doping regulation performance, physical pressure implementation is easy and efficient, cost is reduced, and energy consumption is lower than that of a traditional chemical reaction; the size of the prepared TMP 2 (SbBr5) (SbBr3) single crystal reaches the millimeter level, and the TMP 2 (SbBr5) (SbBr3) single crystal is uniform in size and shape, high in product purity and capable of meeting application requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of nonlinear optics and relates to the application of an organic-inorganic hybrid halide (TMP)2(SbBr5)(SbBr3) with enhanced nonlinear optical effect under high pressure. Background Art

[0002] Nonlinear optics, as an important branch discipline of modern optics, mainly studies the nonlinear interaction laws between the polarization response of matter and the light field intensity under the action of a strong coherent light field and their technical applications. When a high-intensity laser propagates in a medium, its optical-frequency electric field will have a nonlinear interaction with the medium atoms: the nonlinear displacement of the excited electron cloud relative to the atomic nucleus causes the macroscopic polarization intensity of the medium to exhibit high-order nonlinear characteristics. On this basis, crystals with a significant second-order nonlinear coefficient are defined as second-order nonlinear optical crystals, and such materials can achieve laser frequency conversion through second-order nonlinear effects (such as the second-harmonic generation effect, SHG). By precisely controlling the crystal phase-matching conditions, the fundamental frequency light can be effectively converted into second-harmonic light, thereby breaking through the wavelength limitation of traditional lasers and significantly expanding the spectral coverage of laser light sources.

[0003] With the rapid development of science and technology, traditional inorganic nonlinear optical crystals are gradually showing performance bottlenecks in many practical application scenarios and are difficult to meet the growing needs of production practice. Against this background, organic-inorganic hybrid composites are becoming an important research direction in the field of nonlinear optical materials due to their unique structural advantages. From the analysis of material properties, inorganic crystals usually exhibit excellent thermal stability and wide spectral transmission characteristics, while organic molecules show higher polarizability and hyperpolarizability characteristics due to their adjustable molecular configurations. This synergistic effect not only significantly improves the second harmonic generation (SHG) response performance of the material but also endows the material with the unique advantage of structural modifiability, thus providing a broader space for the design of new nonlinear optical crystals. In the exploration of optimizing the performance of nonlinear optical materials, the current mainstream regulation strategies can be divided into two technical paths: "chemical pressure" and "physical pressure". The former precisely regulates the microstructure and macroscopic morphology of the matrix material through chemical modification means such as element doping or defect engineering, thereby improving its nonlinear optical response characteristics. In contrast, the latter shows significant technical advantages. By simply applying a specific hydrostatic pressure to the crystal, a significant improvement in the nonlinear optical properties of the material can be achieved. The enhancement effect of SHG in a high-pressure environment provides a unique technical means for interdisciplinary research. In the field of basic science, its high sensitivity and nanoscale resolution characteristics make it a core tool for detecting high-pressure phase transitions (such as the structural evolution of mantle minerals) and the reconstruction of materials under extreme conditions; at the engineering technology level, this effect can be used in the development of high-pressure tunable photonic chips and miniaturized high-precision pressure sensors. By integrating high-pressure physics, nonlinear optics, and micro-nano manufacturing technologies, the SHG enhancement effect is driving breakthrough innovations in fields such as in-situ detection in extreme environments and dynamic regulation of intelligent materials. Summary of the Invention

[0004] To solve the problems existing in the prior art, the present invention provides an application of an organic-inorganic hybrid halide (TMP)2(SbBr5)(SbBr3) in enhancing the nonlinear optical effect under high-pressure conditions.

[0005] The present invention adopts the following technical solutions:

[0006] An application of a hybrid halide in enhancing the nonlinear optical effect under high-pressure conditions, comprising the following steps:

[0007] (1) Synthesize the hybrid halide;

[0008] (2) Apply hydrostatic pressure to the hybrid halide in a diamond anvil cell to improve its nonlinear optical response.

[0009] Further, the step of synthesizing the hybrid halide in step (1) includes: sequentially adding antimony bromide and thiomorpholine to a hydrobromic acid solution, and evaporating the solution at room temperature. After two weeks, yellow single crystals of the hybrid halide can be obtained.

[0010] Further, the volume of the hydrobromic acid solution is 10 mL.

[0011] Further, the raw material ratio of antimony bromide to thiomorpholine is 1 mmol: 1 mmol.

[0012] Further, the chemical formula of the hybrid halide single crystal is (TMP)2(SbBr5)(SbBr3) (TMP = Thiomorpholine), orthorhombic system, and the space group is Cmc21.

[0013] Further, the unit cell parameters of the hybrid halide single crystal are: a = 16.5328(9); b = 19.7740(11); c = 7.6871(4); α = β = γ = 90°; Z = 4;

[0014] Further, in step (2), a hydrostatic pressure is applied to the hybrid halide in a diamond anvil cell to improve its second-order nonlinear optical response, including the following steps:

[0015] 1) Take a yellow hybrid halide single crystal and press it into a powder pellet.

[0016] 2) Select a steel sheet as the gasket, pre-press it to a certain thickness, use laser drilling within the pre-pressing range as the sample cavity, and place the gasket after drilling on the lower anvil surface of the diamond anvil cell.

[0017] 3) Place the powder pellet from step 1) and a ruby in the sample cavity in sequence, and select a suitable pressure-transmitting medium.

[0018] 4) When the pressure-transmitting medium liquid added completely fills the sample cavity, close the diamond anvil cell and tighten the screws to complete the loading.

[0019] Further, the steel sheet in step 2) is a stainless steel sheet.

[0020] Further, the certain thickness in step 2) is 0.08 mm.

[0021] Further, the pressure-transmitting medium in step 3) is Daphne Oil 7575.

[0022] According to the method provided by the present invention, an application of an organic-inorganic hybrid halide (TMP)2(SbBr5)(SbBr3) under high pressure is obtained. Compared with the existing technology, the present invention has the following advantages:

[0023] (1) The size of the (TMP)2(SbBr5)(SbBr3) single crystal prepared by the present invention reaches the millimeter level, and the size and shape are uniform, and the product purity is high.

[0024] (2) The present invention selects physical pressure as the regulation means. Compared with chemical doping for performance regulation, physical pressure is simple, efficient, reduces costs, and consumes less energy than traditional chemical reactions.

[0025] (3) The test method of the present invention innovatively adopts a powder sample system. The scientific basis is that the nonlinear optical coefficient, as a third-order tensor, has significant anisotropic characteristics. In traditional single-crystal tests, due to the anisotropy of the crystal lattice orientation, the experiment can only detect the components that match the polarization direction of the incident light, which will lead to errors in the test results of the SHG intensity. To overcome this fundamental technical defect, this study realizes a random distribution of spatial orientations by constructing a polycrystalline powder system, effectively eliminating the interference of crystal anisotropy on the test results. Description of the Drawings

[0026] The following will describe the present invention in detail with reference to the accompanying drawings, where:

[0027] Figure 1 is the microscopic optical photograph of the (TMP)2(SbBr5)(SbBr3) crystal.

[0028] Figure 2 is the atmospheric pressure structure and high-pressure structure diagrams of the (TMP)2(SbBr5)(SbBr3) single crystal.

[0029] Figure 3 is the variation diagram of the unit cell parameters and chemical bond lengths of (TMP)2(SbBr5)(SbBr3).

[0030] Figure 4 is the single crystal photograph, absorption spectrum, and the relationship diagram of the energy gap and pressure of the (TMP)2(SbBr5)(SbBr3) crystal under the action of pressure.

[0031] Figure 5 is the emission spectrum diagram of the (TMP)2(SbBr5)(SbBr3) crystal under the action of pressure.

[0032] Figure 6 is the relationship diagram of the SHG effect intensity and pressure of (TMP)2(SbBr5)(SbBr3) under 1550nm laser excitation. Detailed Description of the Embodiments

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] Embodiment 1:

[0035] (TMP)2(SbBr5)(SbBr3) single crystals were synthesized by evaporation method.

[0036] Raw materials used: Thiomorpholine (98%), SbBr3 (99.5%), HBr (47wt%).

[0037] The specific steps are as follows:

[0038] Measure 10mL HBr solution into a beaker, pipette 1mmol of Thiomorpholine into the HBr solution, and stir continuously until the solution changes from turbid to clear. Then weigh 1mmol of SbBr3 and add it into the HBr solution, stir until the raw materials are completely dissolved and the solution is clear. Place the beaker open in a dry and ventilated place. After about two weeks, a large number of millimeter-sized yellow (TMP)2(SbBr5)(SbBr3) crystals will appear in the beaker.

[0039] Embodiment 2:

[0040] The physical pressure is used to enhance the (TMP)2(SbBr5)(SbBr3) nonlinear optical effect.

[0041] The specific steps are as follows:

[0042] (1) taking a portion of (TMP)2(SbBr5)(SbBr3) crystals on a glass plate and pressing them into a powder sheet;

[0043] (2) Select a symmetrical diamond anvil with a diamond anvil surface size of 0.5 mm. Use a T301 stainless steel sheet as a gasket, pre-press it to a thickness of 0.08 mm, use a laser puncher to punch a hole in the pre-pressed area as a sample cavity, and place the punched gasket on the lower anvil surface of the diamond anvil;

[0044] (3) Place a powder tablet in the sample chamber, select the ruby ​​calibration method for pressure calibration, and select DaphneOil 7575 as the pressure transmission medium;

[0045] (4) Drop the pressure medium into the sample cavity. When the pressure medium completely fills the sample cavity, close the upper and lower presses of the diamond anvil and tighten the screws.

[0046] (5) SHG response intensity of the powder sample under pressure test.

[0047] The microscopic optical photograph of the (TMP)2(SbBr5)(SbBr3) single crystal prepared in Example 1 is as follows: Figure 1 As shown in Figure 1, the single crystal is yellow and blocky in appearance. The single crystal structure under normal pressure and high pressure is shown in Figure 1.Figure 2 As shown. At atmospheric pressure, the crystal system of (TMP)2(SbBr5)(SbBr3) is the orthorhombic polar space group Cmc21, and the unit cell parameters are Z = 4, which is called phase α. The crystal structure of phase α consists of SbBr5 square pyramids and SbBr3 triangular pyramids, which are arranged alternately in the ab plane and are not connected to each other. The protonated TMP + cations are intercalated in the voids and interact with the inorganic units through the interactions of CH…Br and NH…Br hydrogen bonds, thus forming a 0D structure. During the pressurization process, (TMP)2(SbBr5)(SbBr3) undergoes an isostructural phase transition, and the space group does not change. In the crystal structure, a new chemical bond Sb-S is formed between the S atom in the TMP organic ring and the Sb atom in the SbBr3 group, while the other inorganic group SbBr5 is connected by sharing vertices with each other to form a one-dimensional Z-shaped chain structure. The changes in the unit cell parameters and chemical bond lengths of (TMP)2(SbBr5)(SbBr3) under pressure in Example 2 are as Figure 3 shown. A sudden interruption of the unit cell parameter a was observed at about 3.50 GPa, while the b-axis and c-axis showed continuous compression. During the structural phase transition, a small volume collapse of about 0.4% (about 0.3% for powder XRD) occurred in the single-crystal XRD, which is a characteristic of the first-order phase transition. The high-pressure in-situ ultraviolet-visible absorption spectroscopy experiment showed the change law of the band gap of (TMP)2(SbBr5)(SbBr3) under pressure, as Figure 4 shown. At atmospheric pressure, (TMP)2(SbBr5)(SbBr3) is yellow and the band gap is 2.60 eV. Due to the shortening of the lengths of Sb-Br and Sb-S bonds, a red shift of the absorption edge occurred under pressure. The band gap became significantly narrower during the pressurization process, decreasing from 2.60 eV to 1.78 eV at 10.85 GPa, and the color of the single crystal gradually changed from yellow to dark red. The photoluminescence spectrum of (TMP)2(SbBr5)(SbBr3) as a function of pressure, as Figure 5 shown. During the pressurization process, the photoluminescence spectrum showed a red shift, and during the phase transition, the position of the photoluminescence peak showed a discontinuous characteristic at about 3.50 GPa. Twelve test points were selected on the surface of the powder sample, and the SHG response intensities of the twelve points were independently measured under the excitation of a 1550-nm laser. After averaging the twelve test values, the SHG response intensity at this pressure was obtained. The relationship between the SHG effect intensity and pressure is as Figure 6 shown. (TMP)2(SbBr5)(SbBr3) showed a continuous increase in SHG intensity over a wide pressure range. When the pressure increased to 8.88 GPa, the SHG intensity increased by about 2.1 times.

[0048] Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An application of hybrid halide to enhance nonlinear optical effect under high pressure environment, characterized in that: The following steps are involved: (1) Synthesis of hybrid halides; (2) Applying hydrostatic pressure to the hybrid halide in a diamond anvil cell can enhance its nonlinear optical response.

2. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 1, characterized in that: The step of synthesizing the hybrid halide in step (1) comprises: adding antimony bromide and thiomorpholine to a hydrobromic acid solution in sequence, evaporating the solution at room temperature, and obtaining a yellow hybrid halide single crystal after two weeks.

3. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 2, characterized in that: The volume of the hydrobromic acid solution is 10 mL.

4. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 2, characterized in that: The raw material ratio of antimony bromide to thiomorpholine is 1 mmol:1 mmol.

5. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 2, characterized in that: The chemical formula of the hybrid halide single crystal is (TMP)2(SbBr5)(SbBr3)(TMP=Thiomorpholine), the crystal system is orthorhombic, and the space group is Cmc21.

6. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 5, characterized in that: The unit cell parameters of the hybrid halide single crystal are: a=16.5328 (9); b=19.7740 (11); c=7.6871 (4); α=β=γ=90°; Z=4; 7. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 1, characterized in that: In step (2), hydrostatic pressure is applied to the hybrid halide in a diamond anvil cell to improve its nonlinear optical response, comprising the following steps: 1) taking a yellow hybrid halide single crystal and pressing it into a powder sheet; 2) Select a steel sheet as a gasket, pre-press it to a certain thickness, use laser drilling within the pre-pressing range as a sample cavity, and place the punched gasket on the lower anvil surface of the diamond anvil; 3) Place the powder flakes and ruby ​​from step 1) in the sample chamber in sequence, and select a suitable pressure transmission medium; 4) When the added pressure-transmitting medium liquid completely fills the sample cavity, close the diamond anvil, tighten the screws, and complete the loading.

8. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 7, characterized in that: The steel sheet in step 2) is a stainless steel sheet.

9. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 7, characterized in that: In step 2), the certain thickness is 0.08 mm.

10. The use of hybrid halides for enhancing nonlinear optical effects under high pressure environment according to claim 7, characterized in that: The pressure transmission medium in step 3) is Daphne Oil 7575.

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