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CN-121975515-A - Quantum dot color conversion fluorescence enhancement method and gold nanorod-quantum dot composite film

CN121975515ACN 121975515 ACN121975515 ACN 121975515ACN-121975515-A

Abstract

The application discloses a quantum dot color conversion fluorescence enhancement method and a gold nanorod-quantum dot composite film, the method comprises providing a gold nanorod with a core-shell structure, wherein the gold nanorod with the core-shell structure comprises a gold nanorod core and a shell layer arranged on the surface of the gold nanorod core; providing a quantum dot solution, mixing the quantum dot solution with gold nanorods with a core-shell structure to form a gold nanorod-quantum dot solution, enabling the wavelength of the quantum dot to be matched with the length-diameter ratio of the gold nanorod core, enabling plasmon resonance peaks of the gold nanorod core and luminescence peaks of the quantum dots to reach coupling resonance, applying an electric field to the gold nanorod-quantum dot solution to induce the gold nanorods to be arranged in a directional mode, and naturally airing and solidifying to form the gold nanorod-quantum dot composite film. The fluorescence enhancement of the quantum dots is induced by the anisotropic local surface plasmon resonance effect of the gold nanorods which are arranged in a directional manner, so that the fluorescence conversion strength, the polarization degree and the light-emitting efficiency of the quantum dot luminescent film are improved.

Inventors

  • HUANG XIAOPING
  • WAN WEIHAO

Assignees

  • 电子科技大学长三角研究院(湖州)

Dates

Publication Date
20260505
Application Date
20260205

Claims (10)

  1. 1. The quantum dot color conversion fluorescence enhancement method is characterized by comprising the following steps of: providing a gold nanorod with a core-shell structure, wherein the gold nanorod with the core-shell structure comprises a gold nanorod core and a shell layer arranged on the surface of the gold nanorod core; Providing a quantum dot solution, mixing the quantum dot solution with the gold nanorods with the core-shell structure to form a gold nanorod-quantum dot solution, wherein the wavelength of the quantum dot light of the quantum dot solution is matched with the length-diameter ratio of the gold nanorod core, so that the plasmon resonance peak of the gold nanorod core and the luminescence peak of the quantum dot reach coupling resonance; And preparing the gold nanorod-quantum dot composite film by using the gold nanorod-quantum dot solution, and applying an electric field to the gold nanorod-quantum dot solution to induce the gold nanorod to be arranged directionally in the process of forming the gold nanorod-quantum dot composite film.
  2. 2. The quantum dot color conversion fluorescence enhancement method according to claim 1, wherein the gold nanorods of the core-shell structure are subjected to structural optimization driven by simulation to determine an aspect ratio and determine a thickness of a shell layer, the thickness of the shell layer is used for regulating and controlling a distance between the quantum dot and a core of the gold nanorods, and the structural optimization driven by the gold nanorods of the core-shell structure comprises the following steps: Providing a gold nanorod, designing a modeling scheme of the gold nanorod by using a finite difference time domain method, and matching a longitudinal surface plasmon resonance peak of the gold nanorod with an excitation light source and a quantum dot absorption spectrum by adjusting the length-diameter ratio of the gold nanorod so as to obtain a maximum local field enhancement factor; Preparing a shell layer on the surface of the gold nanorod to form a gold nanorod with a core-shell structure, performing near-field optical simulation on the nanorod with the core-shell structure by using a finite difference time domain method, performing parameter scanning by changing the thickness of the shell layer on the basis of fixing the length-diameter ratio of the gold nanorod core, calculating local field enhancement change conditions under different thicknesses by using simulation, and selecting the optimal cladding thickness.
  3. 3. The method for enhancing fluorescence of quantum dot color conversion according to claim 1 or 2, wherein the length-diameter ratio of the gold nanorod core is 1.5:1 to 7:1, and the longitudinal surface plasmon resonance peak of the gold nanorod core is matched with the excitation light source and the quantum dot absorption spectrum, so that the maximum local field enhancement factor is obtained.
  4. 4. The quantum dot color conversion fluorescence enhancement method according to claim 3, wherein the particle size of the gold nanorod cores is 30 nm-50 nm, and the length of the gold nanorod cores is 80 nm-200 nm.
  5. 5. The method for enhancing the color conversion fluorescence of the quantum dots according to claim 1 or 4, wherein the thickness of the shell layer is 3 nm-10 nm; The shell layer comprises silicon dioxide, or alternatively, the shell layer comprises a CTAB bilayer.
  6. 6. The quantum dot color conversion fluorescence enhancement method according to claim 1 is characterized in that the step of forming the gold nanorod-quantum dot solution comprises the steps of firstly mixing the gold nanorod with the core-shell structure and the quantum dot solution for 20-30 minutes in an ultrasonic state according to the volume ratio of 1:100-5:100, and then standing the mixed solution for 3-8 minutes to obtain the gold nanorod-quantum dot solution.
  7. 7. The method for enhancing fluorescence of color conversion of quantum dots according to claim 1 or 6, wherein the quantum dot solution is InP quantum dot solution, cdSe quantum dot solution or InAs quantum dot solution, and the luminescence peak of the quantum dot solution reaches coupling resonance.
  8. 8. The method for enhancing fluorescence of color conversion of quantum dots according to claim 7, wherein the quantum dot solution is an InP quantum dot solution, and the luminescence wavelength of InP quantum dots in the InP quantum dot solution is 610 nm to 660 nm; the length-diameter ratio of the gold nanorod core is 2:1 to 3:1, and the thickness of the shell layer is 5 nm-6 nm; at this time, the longitudinal plasmon resonance peak of the gold nanorod core and the luminescence peak of the InP quantum dot reach coupling resonance, and the field enhancement condition and the fluorescence radiation recombination rate reach the cooperative gain degree.
  9. 9. The method for enhancing fluorescence of quantum dot color conversion according to claim 1, wherein in the process of forming the gold nanorod-quantum dot composite film, an alternating electric field is applied to the gold nanorod-quantum dot solution to induce the gold nanorod long axis to be aligned along the direction of an electric field line, and the gold nanorod long axis is cured into a film after natural drying; and the method further comprises the step of carrying out ultrasonic oscillation on the gold nanorod-quantum dot solution, wherein the ultrasonic oscillation damages agglomeration among the nanoparticles so as to prevent the agglomeration among the nanoparticles from weakening fluorescence intensity.
  10. 10. The gold nanorod-quantum dot composite film is characterized in that the gold nanorod-quantum dot composite film is prepared by using the quantum dot color conversion fluorescence enhancement method according to any one of claims 1-9.

Description

Quantum dot color conversion fluorescence enhancement method and gold nanorod-quantum dot composite film Technical Field The application relates to the technical field of quantum dot display, in particular to a quantum dot color conversion fluorescence enhancement method and a gold nanorod-quantum dot composite film. Background With continued advances in display technology, industry applications are experiencing paradigm shift. Emerging applications such as ultra-high definition display, heads-up display (HUD), flexible and wearable displays all require display devices with high resolution, high stability and miniature features. Conventional Liquid Crystal Displays (LCDs) are limited in viewing angle and high in power consumption, and Organic Light Emitting Diodes (OLEDs) are limited in environmental stability, which are difficult to fully satisfy the above-mentioned needs. In contrast, micro LEDs (Micro-LEDs) have become the core of the next generation display technology as an inorganic light emitting diode with a size generally smaller than 100 μm, by virtue of their remarkable advantages of high light extraction efficiency, good current spreading capability, low self-heating effect, short response time, and low power consumption. Currently, the dominant approach to achieving Micro-LED full color display is to rely on Quantum Dot (QD) color conversion layers. However, the scheme still has a remarkable bottleneck that the fluorescence conversion intensity and the light-emitting efficiency of the quantum dot luminescent film are not ideal, and the further improvement of the overall display performance is restricted. Disclosure of Invention The application aims to provide a quantum dot color conversion fluorescence enhancement method and a gold nanorod-quantum dot composite film, which utilize LSPR effect of the gold nanorod and directional arrangement induced by an alternating electric field to improve fluorescence conversion intensity, polarization degree and light-emitting efficiency of a quantum dot luminescent film. In order to achieve the above object, an aspect of the embodiments of the present application provides a quantum dot color conversion fluorescence enhancement method, including the following steps: providing a gold nanorod with a core-shell structure, wherein the gold nanorod with the core-shell structure comprises a gold nanorod core and a shell layer arranged on the surface of the gold nanorod core; Providing a quantum dot solution, mixing the quantum dot solution with the gold nanorods with the core-shell structure to form a gold nanorod-quantum dot solution, wherein the wavelength of the quantum dot light of the quantum dot solution is matched with the length-diameter ratio of the gold nanorod core, so that the plasmon resonance peak of the gold nanorod core and the luminescence peak of the quantum dot reach coupling resonance; And preparing the gold nanorod-quantum dot composite film by using the gold nanorod-quantum dot solution, and applying an electric field to the gold nanorod-quantum dot solution to induce the gold nanorod to be arranged directionally in the process of forming the gold nanorod-quantum dot composite film. According to the application, the anisotropic local surface plasmon resonance effect of the gold nanorods which are arranged in a directional manner is used for inducing the fluorescence enhancement of the quantum dots, so that the light extraction efficiency is improved, the heat loss is reduced, the power consumption of the device in operation is effectively reduced, the service life of the display device is prolonged, and the technical trend of green energy conservation and sustainable development is complied. In an alternative embodiment, the gold nanorods of the core-shell structure determine the length-diameter ratio and the thickness of the shell layer through simulation-driven structural optimization, the thickness of the shell layer is used for regulating and controlling the distance between the quantum dots and the gold nanorod cores, and the simulation-driven structural optimization of the gold nanorods of the core-shell structure comprises the following steps: Providing a gold nanorod, designing a modeling scheme of the gold nanorod by using a finite difference time domain method, and matching a longitudinal surface plasmon resonance peak of the gold nanorod with an excitation light source and a quantum dot absorption spectrum by adjusting the length-diameter ratio of the gold nanorod so as to obtain a maximum local field enhancement factor, wherein the selected gold nanorod is used as a gold nanorod core; Preparing a shell layer on the surface of the gold nanorod to form a gold nanorod with a core-shell structure, performing near-field optical simulation on the nanorod with the core-shell structure by using a finite difference time domain method, performing parameter scanning by changing the thickness of the shell layer on the basis of fixing the lengt