High-speed fluorescent antenna device based on template transfer and preparation method thereof

Abstract

A high-speed fluorescent antenna device based on template transfer and a preparation method thereof, the device comprising a substrate and a fluorescent conversion layer, the fluorescent conversion layer being located on the substrate, characterized in that the fluorescent conversion layer comprises fluorescent powder, a separation layer and regular metal nanoparticles; the regular metal nanoparticles are formed on the surface of the substrate by template transfer, and are metal nanostructures arranged in a periodic array in a horizontal direction; the separation layer is located between the regular metal nanoparticles and the fluorescent powder, and is used for balancing the radiation decay rate and the fluorescence quenching effect, and the regular metal nanoparticles and the fluorescent powder are coupled through surface plasmon resonance. The present application changes the non-radiative loss of quantum dots, realizes the ultrafast radiation of fluorescent materials, and finally shortens the fluorescent light-emitting life.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optoelectronic detection technology, specifically to a high-speed fluorescent antenna device based on template transfer and its fabrication method. Background Technology

[0002] Visible light communication technology, as a wireless communication technology, features unlicensed operation, high security, environmental friendliness, and no electromagnetic radiation. It easily achieves ultra-high-speed communication and can also function as an illumination device. The channel capacity of a visible light communication system is related to the channel bandwidth and the signal-to-noise ratio (SNR) at the receiver. A wider channel bandwidth theoretically allows for the transmission of more information; conversely, a higher SNR at the receiver allows for the accurate decoding of more information. In visible light communication systems, the photosensitive surface of the receiver detector (such as a photodiode) is typically small, resulting in a lower SNR. Furthermore, there is a trade-off between the active area of ​​the detector (i.e., the region that responds to light) and the bandwidth: increasing the active area may reduce the bandwidth, while increasing the bandwidth may require reducing the active area.

[0003] To address the issue of low signal-to-noise ratio at the receiver, a common approach is to combine a focusing system or a compound parabolic concentrator in front of the high-speed detector to focus the light onto a small active area of ​​the detector—that is, an optical antenna. The optical antenna, placed in front of the detector, increases the light-receiving area, thereby maximizing the reception of light energy, increasing the system's signal-to-noise ratio, and improving the bit error rate of the communication system.

[0004] However, traditional optical antennas are limited by the conservation of optical spread, and the amount of incident light is restricted by the field of view of the receiving beam. Therefore, precise field-of-view design of the system is required, as well as ensuring the alignment accuracy between the focusing system and the detector. These requirements make low-cost, dense deployment of communication systems challenging. It is evident that while traditional optical antennas can improve the system's signal-to-noise ratio to some extent, their limited field of view and stringent alignment requirements restrict their application in low-cost, dense deployment scenarios. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a high-speed fluorescent antenna device based on template transfer and its fabrication method. By introducing a localized surface plasmon resonance effect through a metal nanoarray structure, the fluorescence emission lifetime is shortened.

[0006] The objective of this invention is achieved through the following technical solution: A high-speed fluorescent antenna device based on template transfer includes a substrate and a fluorescence conversion layer. The fluorescence conversion layer is disposed on the substrate and includes regular metal nanoparticles, a spacer layer, and phosphor. The regular metal nanoparticles are disposed on the substrate and are transferred from a template to form a periodic metal nanostructure distributed in an array in the horizontal direction. The spacer layer fills the middle and upper layers of the periodic metal nanostructure. The phosphor is disposed on the spacer layer to form surface plasmon resonance.

[0007] Preferably, the smallest array unit of the periodic metal nanostructure is a (rectangular), polygonal, or honeycomb structure.

[0008] Preferably, the center-to-center spacing between two adjacent metal particles in the smallest array unit of the periodic metal nanostructure is 50–3000 nm.

[0009] Preferably, the diameter of the regular metal nanoparticles is 20–500 nm.

[0010] Preferably, the height of the regular metal nanoparticles is 0.5 to 1000 nm.

[0011] Preferably, the shape of the regular metal nanoparticles is any one of nanopillars, nanocones, nanohemispheres, cuboid nanostructures, polygonal nanostructures, and U-shaped nanostructures.

[0012] Preferably, the regular metal nanoparticles include any one or any combination of gold, indium, copper, iron, cobalt, nickel, zinc, aluminum, titanium, vanadium, chromium, manganese, platinum and lead.

[0013] Preferably, the diameter of the regular metal nanoparticles is reduced by annealing.

[0014] Preferably, the phosphor is made of CsPbBr3 / CdSe colloidal quantum dot material.

[0015] Preferably, the substrate is made of glass, quartz, or sapphire.

[0016] Preferably, the template is an ultra-thin AAO template, i.e., a porous anodized aluminum template.

[0017] Preferably, the spacer layer material is an organic compound called PMMA.

[0018] Preferably, the thickness of the spacer layer is 1 nm to 100 nm.

[0019] Preferably, each hole in the template is in the shape of a column, cone, hemisphere, cuboid, polygon, or U.

[0020] Preferably, the center-to-center spacing of the template holes is 50 nm to 3000 nm.

[0021] Preferably, the diameter of the template hole is 30nm to 500nm.

[0022] Preferably, the template film thickness is 0.5 nm to 1000 nm.

[0023] Preferably, this high-speed fluorescent antenna device based on template transfer obtains a periodic metal nanostructure array based on the ultrathin AAO template transfer. Through the annealing operation, the absorption resonance peak of the array is modulated to the vicinity of the quantum dot to regulate the spontaneous emission rate. The spacer layer is placed between the periodic metal nanostructure array and the phosphor to balance the radiation decay rate and fluorescence quenching effect. When the phosphor is located in the near field of the surface of the regular metal nanoparticles, the metal nanostructure introduces a local plasmon resonance effect through strong resonant coupling with photons to regulate the electromagnetic environment of the quantum dot location and enhance the surrounding electromagnetic field. Through energy and charge transfer between the phosphor and the regular metal nanoparticles, the photon density of states is regulated, the non-radiative loss of the quantum dot is changed, and ultrafast emission of the fluorescent material is achieved, ultimately resulting in a shortened fluorescence emission lifetime. A method for fabricating a high-speed fluorescent antenna device based on template transfer, characterized by the following steps: a) Select and prepare the substrate; b) Form a periodic array structure of regular metal nanoparticles on the substrate using template transfer technology; c) Remove the template and anneal the metal nanoparticles to adjust their size to match the emission wavelength of quantum dots; d) Spin-coating an isolation layer material onto the surface of the regular metal nanoparticles; e) Fill the isolation layer with phosphor to form a surface plasmon resonance structure. Preferably, in step b), the template transfer technology uses an ultrathin AAO template, and the shape, size and array distribution of the metal nanoparticles are controlled by adjusting the template parameters. Preferably, in step c), the isolation layer is formed by deposition techniques such as spin coating, sputtering, or evaporation. Preferably, in step d), the phosphor is filled onto the isolation layer by solution method, vapor deposition method or sputtering method.

[0024] Compared with the prior art, the present invention has at least one of the following beneficial effects: (1) By introducing the local surface plasmon resonance effect through the metal nanoarray structure, the electromagnetic field around the fluorescent material is enhanced, thereby increasing the spontaneous emission rate of the material and the modulation bandwidth of the device, making the device potentially valuable for high-speed photoelectric detection and communication. (2) The size of metal nanoparticles is modified and changed by annealing to achieve the optimal state of surface plasmon resonance, which further shortens the fluorescence lifetime and improves the response speed of the device. (3) An organic spacer layer is set between the periodic metal nanostructure array and the phosphor, so that the phosphor is located in the near field of the surface of the regular metal nanoparticles. This not only balances the radiation decay rate and fluorescence quenching effect, but also enhances the stability and lifespan of the device, making the device more reliable and durable in practical applications. Attached Figure Description

[0025] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the structure of an embodiment of the high-speed fluorescent antenna device based on template transfer according to the present invention.

[0027] Figure 2 This is a schematic diagram of a periodic metal nanostructure in an embodiment of the present invention.

[0028] Figure 3 This is a comparison chart of the bandwidth of devices with and without periodic metallic nanostructures.

[0029] Figure 4 This is a fluorescence lifetime diagram of devices with and without periodic metallic nanostructures.

[0030] In the figure, 1 is phosphor, 2 is organic isolation layer, 3 is regular metal nanoparticles, 4 is substrate, and 5 is array unit. Detailed Implementation

[0031] The embodiments of the present invention are described in detail below: These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

[0032] like Figure 1As shown, this example provides a high-speed fluorescent antenna device based on template transfer, including: a substrate and a fluorescence conversion layer. The fluorescence conversion layer is disposed on the substrate and includes phosphor 1, an isolation layer 2, and regular metal nanoparticles 3. The regular metal nanoparticles 3 are spatially periodically arrayed on the surface of the isolation layer 2, forming a periodic metal nanostructure arrayed in the horizontal direction. The isolation layer 2 is located between the regular metal nanoparticles 1 and the phosphor 3, balancing the radiation attenuation rate and fluorescence quenching effect, and forming surface plasmon resonance with the filled phosphor 3.

[0033] The periodic minimum array units of the regular metal nanoparticles are rectangular, polygonal, or honeycomb structures.

[0034] The term "regular metal nanoparticles" refers to metal materials whose particles are nanoscale and arranged in a regular, orderly manner.

[0035] The period refers to the repeated arrangement of the smallest particle arrangement unit.

[0036] Preferably, the center-to-center spacing between two adjacent metal particles in the smallest array unit of the periodic metal nanostructure is 50–3000 nm.

[0037] Preferably, the diameter of the regular metal nanoparticles is 20–500 nm.

[0038] Preferably, the height of the regular metal nanoparticles is 0.5 to 1000 nm.

[0039] Preferably, the shape of the regular metal nanoparticles is any one of nanopillars, nanocones, nanohemispheres, cuboid nanostructures, polygonal nanostructures, and U-shaped nanostructures.

[0040] Preferably, the regular metal nanoparticles include any one or any combination of gold, indium, copper, iron, cobalt, nickel, zinc, aluminum, titanium, vanadium, chromium, manganese, platinum and lead.

[0041] Preferably, the diameter of the regular metal nanoparticles is reduced by annealing.

[0042] Preferably, the phosphor is made of CsPbBr3 / CdSe colloidal quantum dot material.

[0043] Preferably, the substrate is made of glass, quartz, or sapphire.

[0044] Preferably, the template is an ultra-thin AAO template, i.e., a porous anodized aluminum template.

[0045] Preferably, the spacer layer material is an organic compound called PMMA.

[0046] Preferably, the thickness of the spacer layer is 1 nm to 100 nm.

[0047] Preferably, each hole in the template is in the shape of a column, cone, hemisphere, cuboid, polygon, or U.

[0048] Preferably, the center-to-center spacing of the template holes is 50 nm to 3000 nm.

[0049] Preferably, the diameter of the template hole is 30nm to 500nm.

[0050] Preferably, the template film thickness is 0.5 nm to 1000 nm.

[0051] Preferably, this high-speed fluorescent antenna device based on template transfer obtains a periodic metal nanostructure array based on the ultrathin AAO template transfer. Through the annealing operation, the absorption resonance peak of the array is modulated to the vicinity of the quantum dot to regulate the spontaneous emission rate. The spacer layer is placed between the periodic metal nanostructure array and the phosphor to balance the radiation decay rate and fluorescence quenching effect. When the phosphor is located in the near field of the surface of the regular metal nanoparticles, the metal nanostructure introduces a local plasmon resonance effect through strong resonant coupling with photons to regulate the electromagnetic environment of the quantum dot location and enhance the surrounding electromagnetic field. Through energy and charge transfer between the phosphor and the regular metal nanoparticles, the photon density of states is regulated, the non-radiative loss of the quantum dot is changed, and ultrafast emission of the fluorescent material is achieved, ultimately resulting in a shortened fluorescence emission lifetime.

[0052] In a specific embodiment of the present invention, the plasmon effect is obtained by designing the particle size, spacing, and arrangement of specific metal nanomaterials using a transfer template, thereby controlling the resonance frequency and the quantum dot emission position to achieve resonance, thereby improving the device bandwidth and shortening the fluorescence lifetime.

[0053] The technical solutions provided by the above embodiments of the present invention will be further described below with reference to the accompanying drawings and specific application examples.

[0054] like Figure 1 and Figure 2 As shown, this specific example provides a high-speed fluorescent antenna device based on template transfer, including a substrate 4 and a fluorescence conversion layer composed of phosphor 1, an isolation layer 2, and regular metal nanoparticles 3. The regular metal nanoparticles are disposed on the substrate in a laterally periodic array. The isolation layer fills around the regular metal nanoparticles and separates the phosphor from the regular metal nanoparticles, balancing the radiation decay rate and fluorescence quenching effect. The phosphor is located above the isolation layer and forms surface plasmon resonance with the regular metal nanoparticles, ultimately increasing the spontaneous emission rate and shortening the fluorescence lifetime.

[0055] The fabrication of this high-speed fluorescent antenna device based on template transfer includes the following steps: (1) The cleaned SiO2 substrate is subjected to hydrophilic treatment.

[0056] (2) Transfer the template flat onto the substrate, such as an AAO template, with a hole center spacing of 450nm and a hole diameter of 260-340nm.

[0057] (3) A regular array of metal nanoparticles, such as silver, is deposited on a substrate by vapor deposition or sputtering, and then the AAO template is removed. The size of the metal nanoparticles is then changed by annealing to obtain silver particles with a radius of 70 nm.

[0058] (4) Spin-coating PMMA onto the metal nanoparticle array. The concentration of PMMA toluene solution used is 0.1wt%. Spin-coating is performed at 6000rpm / min for 60s, followed by heating to 90℃ for 30 minutes, and then cooling to room temperature to form an isolation layer with a thickness of 10nm.

[0059] A 50 μL solution of 0.2 wt% CsPbBr3 / CdSe quantum dot was drop-coated onto the insulating layer and dried under nitrogen to obtain a fluorescent antenna.

[0060] The comparative example of a fluorescent antenna without a template-transfer-based array of regular metal nanoparticles was fabricated using the following steps: (1) The cleaned SiO2 substrate is subjected to hydrophilic treatment.

[0061] (2) PMMA was spin-coated onto the metal nanoparticle array. The concentration of the PMMA toluene solution used was 0.1wt%. The spin-coating was performed at 6000rpm / min for 60s, followed by heating at 90℃ for 30 minutes, and then cooling to room temperature to form an isolation layer with a thickness of 10nm.

[0062] (3) 50 μL of 0.2 wt% CsPbBr3 / CdSe quantum dot solution was drop-coated onto the isolation layer and dried under nitrogen atmosphere to obtain a fluorescent antenna.

[0063] After comparison Figure 3 and Figure 4 Findings: The high-speed fluorescent antenna device based on template transfer provided by this invention has regular metal nanoparticles. Compared with fluorescent antennas with irregular metal nanoparticles, the 3dB bandwidth of the device is increased by 2.4 times, and the fluorescence emission lifetime is reduced from 3.9ns to 2.9ns, which is significantly shortened.

[0064] 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 high-speed fluorescent antenna device based on template transfer, comprising: A substrate and a fluorescence conversion layer, wherein the fluorescence conversion layer is located on the substrate, characterized in that the fluorescence conversion layer comprises a phosphor, an isolation layer, and regular metal nanoparticles; the regular metal nanoparticles are formed on the surface of the substrate by template transfer, and are arranged in a periodic array in a horizontal direction; the isolation layer is located between the regular metal nanoparticles and the phosphor, and is used to balance the radiation decay rate and the fluorescence quenching effect; the regular metal nanoparticles and the phosphor are coupled through surface plasmon resonance.

2. The high-speed fluorescent antenna device based on template transfer according to claim 1, characterized in that, The periodic minimum array unit of the regular metal nanoparticles is cylindrical, hemispherical, rectangular, polygonal, or honeycomb structure.

3. The high-speed fluorescent antenna device based on template transfer according to claim 1, characterized in that, The distance between the centers of adjacent regular metal nanoparticles is 65–3000 nm.

4. The high-speed fluorescent antenna device based on template transfer according to claim 1 or 3, characterized in that, The diameter of the regular metal nanoparticles is 20–400 nm.

5. The high-speed fluorescent antenna device based on template transfer according to claim 1, characterized in that, The regular metal nanoparticles can be any one of the following: nanopillars, nanocones, nanohemisphers, cuboid nanostructures, polygonal nanostructures, and U-shaped nanostructures.

6. The high-speed fluorescent antenna device based on template transfer according to claim 1, characterized in that, The regular metal nanoparticles include any one or any combination of gold, indium, copper, iron, cobalt, nickel, zinc, aluminum, titanium, vanadium, chromium, manganese, platinum and lead.

7. The high-speed fluorescent antenna device based on template transfer according to claim 1, characterized in that, The phosphor is made of CsPbBr3 / CdSe colloidal quantum dot material.

8. The high-speed fluorescent antenna device based on template transfer according to claim 1, characterized in that, The regular metal nanoparticles are obtained by transfer printing with an ultrathin AAO template, and the array absorption resonance peak is modulated to the vicinity of the quantum dot by annealing to control the spontaneous emission rate.

9. The high-speed fluorescent antenna device based on template transfer according to claim 1 or 8, characterized in that, The template has a uniform porous structure, which can be circular, square, polygonal, or U-shaped.

10. A method for fabricating a high-speed fluorescent antenna device based on template transfer, characterized in that, Includes the following steps: a) Select and prepare the substrate; b) A periodic array structure of regular metal nanoparticles is formed on the substrate using template transfer technology; c) Remove the template and anneal the metal nanoparticles to adjust their size to match the quantum dot emission wavelength; d) Spin-coating an isolation layer material onto the surface of the regular metal nanoparticles; e) Fill the isolation layer with phosphor to form a surface plasmon resonance structure.

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