Polarized fluorescent composite structure, preparation method, application, memory and micro-led

Abstract

The application relates to a polarized fluorescent composite structure, a preparation method, application, a memory and a Micro-LED, and comprises the following steps: firing a mol of silicon dioxide, b mol of germanium dioxide, c mol of lead halide, d mol of cesium salt and e mol of auxiliary materials into a glass matrix, the outer wall surface of the glass matrix comprises a first surface, wherein a>=0, b>=0, c>0, d>0, e>=0, (a+b) / (a+b+c+d+e) is greater than or equal to 0.7; controlling polarized laser to be incident to the inside of the glass matrix from the first surface to focus and form a focal point, the polarized laser makes the lead halide and the cesium salt at the focal point react to generate a perovskite, and part of the glass is converted into a nano-grating, and the nano-grating is located between the first surface of the glass and the perovskite.

Description

Technical Field

[0001] This invention relates to the field of femtosecond laser processing, and in particular to polarized fluorescence composite structures, preparation methods, applications, memory, and Micro-LEDs. Background Technology

[0002] In recent years, lead halide perovskite nanocrystals, as an optical material with fluorescent properties, have attracted considerable attention due to their promising applications in color displays and optoelectronic devices. To achieve polarized fluorescence using perovskite, it is generally necessary to modify its crystal structure to make it anisotropic. However, the complex synthesis process and the difficulty in polarization manipulation greatly limit its applications. Summary of the Invention

[0003] Therefore, it is necessary to address the challenge of obtaining polarized fluorescence from perovskites by providing a polarized fluorescence composite structure, preparation method, application, memory, and Micro-LED.

[0004] A method for preparing a polarized fluorescence composite structure, comprising:

[0005] A glass matrix is ​​prepared by firing a mol silicon dioxide, b mol germanium dioxide, c mol lead halide, d mol cesium salt and e mol additives. The outer wall of the glass matrix includes a first surface, wherein a≥0, b≥0, c>0, d>0, e≥0, and (a+b) / (a+b+c+d+e)≥0.7.

[0006] A polarized laser is controlled to be incident from the first surface into the interior of the glass substrate and focused to form a focal point. The polarized laser causes lead halide and cesium salt at the focal point to react and form perovskite, and transforms a portion of the glass into a nanograting. The nanograting is located between the first surface of the glass and the perovskite.

[0007] A polarized fluorescence composite structure, comprising:

[0008] A glass substrate contains a mol silicon dioxide, b mol germanium dioxide, c mol lead halide, d mol cesium salt and e mol additives, wherein a≥0, b≥0, c>0, d>0, e≥0, (a+b) / (a+b+c+d+e)≥0.7, and the outer wall surface of the glass substrate includes a first surface;

[0009] Perovskite, located within the glass matrix; and

[0010] A nanograting is located within the glass substrate and between the first surface and the perovskite.

[0011] An application of a fabrication apparatus, the fabrication apparatus comprising, in sequence along the light propagation direction, a laser, a half-wave plate, an objective lens, and a support stage, wherein a glass substrate containing a mol silicon dioxide, b mol germanium dioxide, c mol lead halide, d mol cesium salt, and e mol excipients is placed on the support stage, wherein a≥0, b≥0, e≥0, and (a+b) / (a+b+c+d+e)≥0.7, the outer wall surface of the glass substrate includes a first surface, which is positioned facing the objective lens, the half-wave plate modulates the laser emitted by the laser into a polarized laser, and the objective lens focuses the polarized laser onto the glass substrate to obtain a polarized fluorescence composite structure.

[0012] In this invention, the normal to the first surface extends along a first direction, and the support platform is movable at least in the first direction.

[0013] The half-wave plate of the present invention is rotatably disposed between the laser and the objective lens.

[0014] The preparation apparatus of the present invention includes a controller, a first driving unit and a second driving unit. The first driving unit is used to control the rotation of the half-wave plate, and the second driving unit is used to control the movement of the support platform. Both the first driving unit and the second driving unit are electrically connected to the controller.

[0015] The fabrication apparatus of the present invention further includes an attenuator located between the laser and the half-wave plate.

[0016] The single pulse energy of the laser described in this invention is not less than 500 nJ.

[0017] A memory comprising a polarized fluorescence composite structure.

[0018] A Micro-LED comprising a polarized fluorescent composite structure.

[0019] The beneficial effects of the present invention include at least one of the following:

[0020] 1. By focusing a polarized laser inside a glass substrate and controlling the molar fraction of silicon dioxide and / or germanium dioxide in the glass substrate, a nanograting can be inscribed inside the glass substrate by the polarized laser.

[0021] 2. By adjusting the polarization angle of the polarized laser, the tilt angle of the nanograting can be changed, thereby synthesizing a nanograting with an ideal pattern.

[0022] 3. When polarized laser light enters the interior of a glass substrate, it can create a gradient temperature field, which in turn promotes the reaction of lead halide and cesium salt in the glass substrate to form perovskite with fluorescent properties.

[0023] 4. The combination of perovskite and nanograting can form polarized fluorescence, eliminating the need to synthesize anisotropic perovskite and reducing the requirements for perovskite synthesis. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the front view of the polarization-fluorescence composite structure in Embodiment 1 of the present invention;

[0025] Figure 2 This is a schematic diagram of the preparation apparatus in Embodiment 3 of the present invention;

[0026] Figure 3 This is a scanning electron micrograph of the polarized fluorescence composite structure in backscatter mode in Embodiment 3 of the present invention;

[0027] Figure 4 These are SEM images of the nanograting at different rotation angles of the half-wave plate in Embodiment 3 of the present invention.

[0028] Figure 5 The degree of polarization of the polarized laser generated by the half-wave plate at different rotation angles in Embodiment 3 of the present invention;

[0029] Figure 6 The photoluminescence spectrum of the polarized fluorescent composite structure in Example 1 of this invention;

[0030] Figure 7 These are photographs of the polarized fluorescence composite structure after laser irradiation at different repetition frequencies in Example 5 of this invention.

[0031] Figure 8 This is a SEM image of the polarized fluorescence composite structure formed under the irradiation of polarized lasers with different pulse energies in Embodiment 3 of the present invention within xoz.

[0032] Figure 9 These are photographs of the polarized fluorescence composite structure after laser irradiation with different pulse energies in Embodiment 5 of the present invention.

[0033] Figure label:

[0034] 1. Glass substrate; 11. First surface; 2. Nanograting; 3. Perovskite; 41. Laser; 42. Glan prism; 43. Attenuator; 44. First drive unit; 45. Camera; 46. Dichroic mirror; 47. Objective lens; 48. Support stage; 49. Controller. Detailed Implementation

[0035] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0041] Example 1:

[0042] See Figure 1 This embodiment provides a polarization fluorescence composite structure, including a glass substrate 1, a perovskite 3, and a nanograting 2.

[0043] The glass substrate 1 is flat, and its outer wall includes a first surface 11 and a second surface. Both the first surface 11 and the second surface are planes, wherein the normal of the first surface 11 extends along a first direction, and the first surface 11 and the second surface are arranged opposite to each other in the first direction.

[0044] Specifically, the raw materials of the glass matrix 1 include a mol silicon dioxide, b mol germanium dioxide, c mol lead halide, d mol cesium salt and e mol auxiliary materials, wherein a≥0, b≥0, c>0, d>0, e≥0, and (a+b) / (a+b+c+d+e)≥0.7.

[0045] Silica and germanium dioxide are the main raw materials constituting the glass substrate 1, and they can be substituted for each other. Therefore, the raw materials of the glass substrate 1 can contain both silica and germanium dioxide, or only one of them. Thus, it is only necessary to satisfy a + b > 0, where a or b can be equal to 0. Common choices are a = 0, b > 0, or b = 0, a > 0, or a > 0, b > 0.

[0046] Perovskite 3 is located within the glass substrate 1 and is generally planar. In this embodiment, perovskite 3 is generally parallel to the first surface 11. In this embodiment, perovskite 3 is synthesized from lead halide and cesium salt within the glass substrate 1; therefore, the specific chemical formula of perovskite 3 is determined by lead halide and cesium salt. In this embodiment, cesium carbonate is used as the cesium salt. The synthesized perovskite 3 exhibits fluorescent properties but does not require anisotropy, thus its synthesis is relatively simple.

[0047] The nanograting 2 is also located within the glass substrate 1 and is distributed in a planar manner. The nanograting 2 is also parallel to the first surface 11 and is positioned between the first surface 11 and the perovskite 3. Thus, the fluorescence generated by the perovskite 3 can form polarized fluorescence under the action of the nanograting 2.

[0048] See Figure 6 32W / cm is used on the second surface. 2 The perovskite was irradiated with ultraviolet light, and its emission spectrum was collected every 5 minutes. The peak value and intensity of the perovskite did not change significantly within 30 minutes.

[0049] Example 2:

[0050] This embodiment provides a method for preparing a polarized fluorescence composite structure to synthesize the polarized fluorescence composite structure in Example 1. The preparation method includes the following steps:

[0051] Step S1: A glass substrate 1 is prepared by sintering a mol silicon dioxide, b mol germanium dioxide, c mol lead halide, d mol cesium salt, and e mol auxiliary materials. The substrate is then annealed and polished, causing a portion of the outer wall surface of the glass substrate 1 to be converted into the first surface. The auxiliary materials include, but are not limited to, one or more of other raw materials such as zinc oxide and sodium halide.

[0052] Where a≥0, b≥0, c>0, d>0, e≥0, (a+b) / (a+b+c+d+e)≥0.7.

[0053] Step S2: Control the polarized laser to be incident perpendicularly from the first surface into the interior of the glass substrate along the first direction and focus it to form a focal point, thereby obtaining a polarized fluorescence composite structure.

[0054] The portion of the glass substrate between the focal point and the first surface is gradually transformed into a nanograting under the action of polarized laser etching. The working principle is that the polarized laser induces the self-organization behavior of oxygen defects, and the deflection angle of the nanograting is related to the polarization angle of the polarized laser. By changing the polarization angle of the polarized laser, the nanograting can form different deflection angles.

[0055] Polarized lasers can convert the portion of a glass substrate between the focal point and the first surface into a nanograting, which depends on the relationship (a+b) / (a+b+c+d+e)≥0.7. That is, if this relationship is not satisfied, polarized lasers cannot form a nanograting inside the glass substrate.

[0056] A polarized laser simultaneously creates a temperature field within the glass matrix, which induces phase separation within the glass matrix. The polarized laser has the highest energy at the focal point, thus inducing the reaction of lead halide and cesium salt at the focal point to form perovskite.

[0057] The nanograting is located between the first surface of the glass and the perovskite. The perovskite fluoresces under ultraviolet light excitation, and the fluorescence is modulated when it shines on the nanograting. Due to the presence of a temperature field, there is also a transition layer between the layered nanograting and the perovskite, which is composed of a mixture of the nanograting and the perovskite.

[0058] In this embodiment, both the nanograting and the perovskite inside the glass substrate are generated by polarized laser. Therefore, the nanograting and the perovskite are opposite each other in the first direction, and the nanograting is completely projected onto the perovskite in the first direction, and the perovskite is also completely projected onto the nanograting in the first direction.

[0059] Example 3:

[0060] See Figure 2 This embodiment provides a preparation apparatus that can implement the preparation method of the polarized fluorescence composite structure in Example 2 to obtain the polarized fluorescence composite structure in Example 1.

[0061] The fabrication apparatus includes a laser 41, a Glan prism 42, an attenuator 43, a half-wave plate, a dichroic mirror 46, an objective lens 47, a camera 45, a support stage 48, a controller 49, a first drive unit 44, and a second drive unit.

[0062] The laser 41, Glan prism 42, attenuator 43, half-wave plate, dichroic mirror 46, objective lens 47 and support stage 48 are arranged sequentially along the direction of light propagation.

[0063] The glass substrate 1 obtained in step S1 of Example 2 is placed on the support stage 48, with its first surface facing the objective lens 47. A half-wave plate is mounted on a first driving unit 44, which controls the rotation of the half-wave plate. In this example, the first direction is the z-axis direction. The second driving unit can not only move the support stage 48 along the z-axis, but also move it along the x and y axes.

[0064] In this embodiment, laser 41 is a femtosecond laser with a center wavelength of 1030 nm, a power of 10 W, an adjustable pulse width range of 190 fs to 10 fs, and a maximum repetition frequency of 1000 kHz. The pulsed laser emitted by laser 41 is modulated into polarized laser by a half-wave plate, and objective lens 47 focuses the polarized laser into the glass substrate 1, thereby simultaneously forming a nanograting and perovskite within the glass substrate 1. (See [reference]). Figure 3 In this way, a polarized fluorescence composite structure was obtained.

[0065] When the second drive unit controls the support stage 48 to move in the z-axis direction, the distance between the glass substrate 1 and the objective lens 47 on the z-axis will also change. As a result, the focusing position of the polarized laser in the glass substrate 1 will also change, and correspondingly, the formation depth of the nanograting in the glass substrate 1 will also change. Based on this, in conjunction with the movement of the support stage 48 in the x-axis and y-axis directions, three-dimensional polarized fluorescence pattern writing in the glass substrate 1 can be controllably realized.

[0066] Furthermore, the rotation of the half-wave plate is controlled by the first drive unit 44, see [link / reference]. Figure 4 and Figure 5 This allows us to change the polarization degree of the polarized laser, thereby altering the deflection angle of the nanograting.

[0067] Based on this, both the first driving unit 44 and the second driving unit are electrically connected to the controller 49. The controller 49 controls the movement of the glass substrate 1 to match the rotation of the half-wave plate, thereby forming a target patterned nanograting structure within the glass substrate 1. Thus, the nanograting in the polarized fluorescence composite structure possesses not only three-dimensional position information but also deflection angle information. When the fluorescence generated by the perovskite irradiates the nanograting, the position and deflection angle information of the nanograting can be used to encode and decode information. Therefore, the polarized fluorescence composite structure can be used for information storage.

[0068] If the laser pulse energy is too high, perovskite will also form between the nanograting and the first surface. As a result, when ultraviolet light is irradiated at the second surface, the fluorescence generated by the perovskite between the nanograting and the first surface may be emitted directly from the first surface without being modulated by the nanograting. The attenuator 43 limits the power of the laser pulse, which can effectively avoid the above situation.

[0069] See Figure 8 In this embodiment, laser 41 irradiates the glass substrate 1 with lasers of different pulse energies to form a polarized fluorescence composite structure. The x-axis and z-axis constitute the xoz plane. When the glass substrate 1 is irradiated with a 300 nJ laser pulse, only the formation of a nanograting can be observed in the xoz plane, but the formation of perovskite nanocrystals is not observed. However, when the laser pulse energy is increased to 500 nJ and 750 nJ, perovskite nanocrystals and dot-like nanostructures are generated, respectively. It can be seen that the single pulse energy of laser 41 is not less than 500 nJ, which is necessary to enable the polarized laser to simultaneously control the formation of nanogratings and perovskites.

[0070] Example 4:

[0071] This embodiment provides a memory, including the polarization-fluorescence composite structure of Embodiment 1. The polarization-fluorescence composite structure utilizes the three-dimensional position information and deflection angle information of the nanograting to encode and decode fluorescence information, thereby realizing the storage and retrieval of information.

[0072] Example 5:

[0073] This embodiment provides a Micro-LED, comprising a substrate, a circuit board, an encapsulation layer, and a polarized phosphor composite structure stacked from bottom to top. The encapsulation layer contains a GaN light-emitting array.

[0074] See Figure 7 The perovskite in the polarized fluorescence composite structure was irradiated with 405 nm ultraviolet light at repetition frequencies of 80 kHz, 100 kHz, 120 kHz, and 140 kHz, with a pulse duration of 1 ps, a pulse energy of 750 nJ, and a laser scanning speed of 80 μm / s. After modulation by a nanograting, images were captured in optical microscope, birefringence microscope, and fluorescence microscope images, respectively. As can be seen from the images, the nanograting exhibited the best modulation effect when irradiated with a laser at a repetition frequency of 120 kHz.

[0075] See Figure 9 The perovskite in the polarized fluorescence composite structure was irradiated with 405 nm ultraviolet light at a repetition frequency of 120 kHz, a pulse duration of 1 ps, and pulse energies of 300 nJ, 500 nJ, 750 nJ, 1000 nJ, and 1250 nJ, with a laser scanning speed of 80 μm / s. After modulation by a nanograting, images were captured in optical microscope images, birefringence microscope images, and fluorescence images, respectively. As can be seen from the figures, the signal intensity was the highest in the birefringence microscope image when a pulse energy of 750 nJ was used.

[0076] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a polarized fluorescence composite structure, characterized in that, include: A glass matrix is ​​prepared by firing a mol silicon dioxide, b mol germanium dioxide, c mol lead halide, d mol cesium salt and e mol auxiliary materials. The outer wall surface of the glass matrix includes a first surface, wherein a≥0, b≥0, c>0, d>0, e≥0, and (a+b) / (a+b+c+d+e)≥0.

7. A polarized laser is controlled to be incident from the first surface into the interior of the glass substrate and focused to form a focal point. The polarized laser causes lead halide and cesium salt at the focal point to react and form perovskite, and transforms a portion of the glass into a nanograting. The nanograting is located between the first surface of the glass and the perovskite.

2. A polarized fluorescence composite structure, characterized in that, It was prepared using the method described in claim 1 for preparing the polarized fluorescence composite structure.

3. An application of a preparation apparatus, characterized in that, The fabrication apparatus comprises, in sequence along the light propagation direction, a laser, a half-wave plate, an objective lens, and a support stage. A glass substrate containing a mol silicon dioxide, b mol germanium dioxide, c mol lead halide, d mol cesium salt, and e mol excipients is placed on the support stage, wherein a≥0, b≥0, c>0, d>0, e≥0, and (a+b) / (a+b+c+d+e)≥0.

7. The outer wall surface of the glass substrate includes a first surface, which is positioned facing the objective lens. The half-wave plate modulates the laser emitted by the laser into a polarized laser, and the objective lens focuses the polarized laser onto the glass substrate to obtain the polarized fluorescence composite structure as described in claim 2.

4. The application of the preparation apparatus according to claim 3, characterized in that, The normal to the first surface extends along a first direction, and the support platform is movable at least in the first direction.

5. The application of the preparation apparatus according to claim 3, characterized in that, The half-wave plate is rotatably positioned between the laser and the objective lens.

6. The application of the preparation apparatus according to claim 5, characterized in that, The preparation apparatus includes a controller, a first driving unit, and a second driving unit. The first driving unit is used to control the rotation of the half-wave plate, and the second driving unit is used to control the movement of the support platform. Both the first driving unit and the second driving unit are electrically connected to the controller.

7. The application of the preparation apparatus according to claim 3, characterized in that, The fabrication apparatus further includes an attenuator located between the laser and the half-wave plate.

8. The application of the preparation apparatus according to claim 7, characterized in that, The single pulse energy of the laser is not less than 500 nJ.

9. A memory, characterized in that, Includes the polarized fluorescence composite structure as described in claim 2.

10. A Micro-LED, characterized in that, Includes the polarized fluorescence composite structure as described in claim 2.

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