Based on single lanthanide Er 3+ Color display system and display method for regulating ion excited state population

Abstract

The present invention discloses a method based on single lanthanide Er 3+ A color display system and a display method for regulating the ion excited state population, belonging to the technical field of nano-optical display equipment, including a single lanthanide Er 3+ Three-dimensional / two-dimensional color solid display matrix of ion-doped NaYF4 nanoparticle / polymer composite material, optical lens group, 980 / 1973nm cooperative excitation laser system and laser scanner; the present invention realizes single lanthanide Er through 980 / 1973nm near-infrared light cooperative excitation 3+ The layout of the excited state of ions is regulated, and dynamic multi-color up-conversion luminescence regulation from green to yellow-green, yellow, orange, and finally red is achieved by increasing the 1973nm near-infrared light excitation power. Finally, by making the NaYF4:Er up-conversion nanomaterial based on dynamic multi-color luminescence changes into a display medium, three-dimensional / two-dimensional color display imaging with high optical resolution is achieved. The present invention improves the color purity and pixels of multi-color up-conversion luminescence, and realizes true three-dimensional stereoscopic display with nanometer-level resolution.

Description

Technical Field

[0001] The present invention belongs to the technical field of nano-optical display devices, and specifically relates to a nano-optical display device based on a single lanthanide Er 3+ A color display system and a display method for regulating ion excited state population. Background Art

[0002] Multicolor upconversion luminescence has broad application prospects in the fields of color display, multicolor optical coding, advanced anti-counterfeiting, multicolor fluorescence imaging and treatment. The realization of precise and controllable multicolor upconversion luminescence has important research significance and application value. In the past few decades, researchers have conducted a lot of research on the regulation of upconversion multicolor luminescence, such as obtaining multicolor upconversion luminescence by co-doping with multiple lanthanide luminescent ions, layering different lanthanide luminescent ions through core-shell structures, or mixing multiple luminescent nanomaterials. However, these methods based on multiple lanthanide luminescent ions usually cause problems such as excitation light crosstalk, mutual interference of multiple luminescence processes, and harmful energy transfer, resulting in overlapping of multicolor upconversion luminescence, uneven luminescence color, and inconsistent brightness, which seriously limits the color pixels and optical resolution of color display imaging, and hinders the application and development of multicolor upconversion luminescent materials in the display field.

[0003] Therefore, it is of great significance to develop a simpler method for regulating multicolor upconversion luminescence based on a single lanthanide ion. Summary of the invention

[0004] In view of the problems that the methods based on multiple lanthanide luminescent ions in the prior art usually cause crosstalk of excitation light, mutual interference of multiple luminescence processes, harmful energy transfer, etc., the present invention provides a method based on a single lanthanide Er 3+ A color display system and a display method for regulating the ion excited state population. The color display matrix of the display system of the present invention is based on a single lanthanide Er 3+ Ion-doped NaYF4 nanomaterials are used as luminescent media, polymer materials are used as three-dimensional display solid media, and nanocrystal / polymer composite materials with high transparency are prepared by doping or copolymerization. 3+ The multicolor luminescence regulation of ions (green, yellow-green, yellow, orange, red) can obtain high color purity and multicolor up-conversion luminescence of pixels, providing a basis for realizing three-dimensional / two-dimensional color display imaging with high optical resolution; the present invention is based on the synergistic excitation of 980 / 1973nm near-infrared laser, by fixing the excitation power of 980nm excitation light (200mW) and gradually increasing the excitation power of 1973nm excitation light (0-1200mW), in a single lanthanide Er 3+ The excited state population pathway from the green light emission level is realized in ion-doped NaYF4 nanomaterials 2H 11 / 2 / 4 S 3 / 2 To the red emission level 4 F 9 / 2 regulation.

[0005] The multicolor upconversion luminescence regulation mechanism of the present invention is as follows:

[0006] Under 980nm near-infrared light excitation, Er 3+ Ions absorb 980nm photons from the ground state 4 I 15 / 2 Energy level transition to 4 F 7 / 2 energy level, followed by non-radiative relaxation to the green light emitting level 2 H 11 / 2 / 4 S 3 / 2 , and finally through 2 H 11 / 2 / 4 S 3 / 2 → 4 I 15 / 2 When 980nm near-infrared light is combined with 1973nm near-infrared light for synergistic excitation, increasing the excitation power of 1973nm near-infrared light promotes Er 3+ Ions populate the red emission level via a 980 / 1973nm two-photon process 4 F 9 / 2 energy level, and then radiatively relaxes back to 4 I 15 / 2 The ground state produces red light emission. The single lanthanide Er is excited by the power-adjustable 980 / 1973nm near-infrared light synergistic excitation. 3+ By regulating the population of ion excited states, we ultimately obtain dynamic multi-color upconversion luminescence that is adjustable from green to yellow-green, yellow, orange, and then to red.

[0007] The present invention is achieved through the following technical solutions:

[0008] A single lanthanide Er-based 3+ Ion excited state population regulation to achieve multicolor upconversion luminescence display system, including single lanthanide Er 3+A three-dimensional / two-dimensional color solid display matrix of ion-doped NaYF4 nanoparticle / polymer composite material, an optical lens group, a 980 / 1973nm cooperative excitation laser system and a laser scanner; the optical lens group includes a laser collimating lens and a telephoto lens; the 980 / 1973nm cooperative excitation laser system is formed by coupling a 980nm near-infrared continuous laser and a 1973nm near-infrared continuous laser through a wavelength division multiplexer; the two coupled laser beams are converged at a fixed point position in the three-dimensional / planar space of the three-dimensional / two-dimensional color solid display matrix through a telephoto lens, and color display imaging is performed by adjusting the excitation power of the 980 / 1973nm cooperative excitation and using a laser scanner; the laser scanner is used to control the laser convergence point to scan in the three directions of the X, Y and Z axes in the color solid display matrix according to the set three-dimensional image data, and a color three-dimensional display image composed of countless nano-body pixel points can be obtained by adjusting the excitation power of the 980 / 1973nm cooperative excitation and using the persistence effect of human eye vision.

[0009] Furthermore, the focal length of the convex lens is 5-25 mm, and the focal length of the telephoto lens is 3-15 cm.

[0010] Furthermore, the three-dimensional / two-dimensional color solid display matrix is ​​a three-dimensional / two-dimensional color solid display matrix based on NaYF4:Er / polymer composite material with high transparency, which is prepared by doping or copolymerization using NaYF4:Er (1-20%) upconversion nanomaterials as the luminescent medium and polymer materials as the three-dimensional display solid medium.

[0011] Furthermore, the polymer material is epoxy resin AB glue, polymethyl methacrylate or polydimethylsiloxane.

[0012] Furthermore, the single lanthanide Er 3+ The ion-doped NaYF4 nanoparticles are prepared by a thermal coprecipitation method, which specifically comprises the following steps:

[0013] A 50mL two-necked round-bottom flask was used as a reaction container, and 3mL of oleic acid and 7mL of octadecene were added to an aqueous solution of Y(CH3COO)3 and Er(CH3COO)3 in a predetermined ratio with a total amount of 0.4mmol. The resulting mixture was stirred at 150°C for 60 minutes to remove water and low-boiling solvent molecules to form an oleic acid complex precursor; after the resulting mixture was cooled to room temperature, 4mL of NH4F (0.4moL / L) and 2mL of NaOH (0.5moL / L) methanol solution were added and the mixture was heated to 50°C and stirred continuously for 30 minutes, then heated to 100°C and kept under vacuum for 10 minutes to remove methanol, and then heated to 290°C under inert gas protection for 90 minutes; after the reaction was completed, it was cooled to room temperature, the prepared nanoparticles were precipitated by centrifugal separation, and then washed repeatedly with cyclohexane and ethanol several times, and finally the product was dispersed in cyclohexane.

[0014] Furthermore, the single lanthanide Er 3+ The preparation method of the three-dimensional / two-dimensional color solid display matrix of ion-doped NaYF4 nanoparticles / polymer composite material comprises the following specific steps:

[0015] A cyclohexane solution containing NaYF4:Er nanoparticles (30 mg / mL) was dispersed in an epoxy resin, stirred at room temperature for 20 minutes, and then a curing agent was added and stirred at room temperature for 30 minutes; wherein the volume ratio of the cyclohexane solution of the nanoparticles, the epoxy resin and the curing agent was 1:2.5:1; after being completely and fully mixed, the mixture was centrifuged for 5 minutes to remove bubbles, and then poured into a silicone mold and heated to 50°C in a vacuum drying oven for curing for 48 hours, and then demolded after cooling to room temperature to obtain a nanomaterial / epoxy resin AB glue composite color solid display matrix.

[0016] On the other hand, the present invention also provides a single lanthanide Er 3+ The display method of the display system for realizing multi-color up-conversion luminescence by regulating the ion excited state population specifically comprises the following steps:

[0017] Step 1: Combine NaYF4:Er nanomaterials with epoxy resin AB glue by doping or copolymerization, pour into silicone molds of various geometric shapes (such as cuboids and rectangles) for curing, and prepare a high-transparency color display matrix based on nanocrystal / polymer composite materials;

[0018] Step 2: A laser system formed by coupling a 980nm near-infrared continuous laser and a 1973nm near-infrared continuous laser through a wavelength division multiplexer is used as a pump source, and the coupled laser is focused at a fixed point in the three-dimensional / two-dimensional color solid display matrix through a telephoto lens;

[0019] Step 3: Output image data through 3D modeling software, use the laser scanner main controller to receive signals, control the laser convergence point to scan in the color solid display matrix in the X, Y, and Z axis directions, and obtain a color three-dimensional display image composed of countless nano-body pixels by adjusting the excitation power of 980 / 1973nm co-excitation and utilizing the persistence effect of human vision.

[0020] Furthermore, the excitation power of the 980 / 1973nm cooperative excitation is adjusted by fixing the excitation power of the 980nm excitation light at 200mW and gradually increasing the excitation power range of the 1973nm excitation light to 0-1200mW, thereby achieving dynamic multi-color upconversion luminescence regulation from green to yellow-green, yellow, orange, and finally red in the NaYF4:Er upconversion nanomaterial.

[0021] Furthermore, the specific control method for adjusting the excitation power of 980 / 1973nm cooperative excitation includes the following contents:

[0022] When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 0mW, green upconversion luminescence is generated;

[0023] When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 220mW, yellow-green upconversion luminescence is generated;

[0024] When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 460mW, yellow up-conversion luminescence is generated;

[0025] When the power of the 980nm laser is 200mW and the power of the 1973nm laser is 620mW, orange upconversion luminescence is generated;

[0026] When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 1200mW, red up-conversion luminescence is generated.

[0027] Compared with the prior art, the advantages of the present invention are as follows:

[0028] The present invention is based on single lanthanide Er 3+ The color display system and display method regulated by ion excited state population avoid problems such as excitation light crosstalk, mutual interference of multi-color luminescence or harmful energy transfer caused by doping with multiple lanthanide ions, can improve the color purity and pixels of multi-color up-conversion luminescence, and can achieve three-dimensional color display with high optical resolution and body pixels. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0030] Figure 1 :Schematic diagram of the green luminescence mechanism of NaYF4:Er upconversion nanomaterials under 980nm wavelength excitation;

[0031] Figure 2 :Schematic diagram of the red luminescence mechanism of NaYF4:Er upconversion nanomaterials under the synergistic excitation of 980 / 1973nm near-infrared light;

[0032] Figure 3 : Transmission electron microscopy (TEM) images and particle size distribution of NaYF4:Er upconversion nanomaterials;

[0033] As can be seen from the figure, the prepared nanoparticles are monodisperse, spherical with uniform morphology, and the average size is 28 nm;

[0034] Figure 4 :High-resolution transmission electron microscopy (HRTEM) image based on NaYF4:Er upconversion nanomaterials;

[0035] As can be seen from the figure, the spacing of the lattice fringes is 0.52 nm, corresponding to the (100) plane of the hexagonal phase NaYF4, indicating that the prepared nanomaterial is a highly crystallized hexagonal NaYF4 crystal;

[0036] Figure 5 : Scanning transmission electron microscopy (STEM) images of three randomly adjacent NaYF4:Er nanoparticles and the corresponding F, Y, and Er element distribution maps;

[0037] As can be seen from the figure, these elements are evenly distributed throughout the nanoparticles;

[0038] Figure 6 :EDX spectrum based on NaYF4:Er upconversion nanomaterials;

[0039] It can be seen from the figure that the elements Na, Y, F, and Er are present in the synthesized nanoparticles, which is consistent with the elements of the raw materials used to prepare the nanoparticles;

[0040] Figure 7 : X-ray diffraction patterns of upconversion nanomaterials based on NaYF4:x%Er (x=1, 2, 5, 8, 10, 12, 15 and 20 mol%);

[0041] It can be seen from the figure that the prepared 3+ The diffraction peaks of upconversion nanoparticles with different ion doping concentrations correspond to the standard cards one by one, indicating that the synthesized upconversion nanomaterials are pure hexagonal NaYF4 nanocrystals;

[0042] Figure 8 : Upconversion emission spectra of upconversion nanomaterials based on NaYF4:x%Er (x=1, 2, 5, 8, 10, 12, 15 and 20 mol%) under 980 nm wavelength excitation;

[0043] As can be seen from the figure, when Er 3+ When the ion doping concentration is 8 mol%, the green emission peak is the strongest under 980nm near-infrared light excitation, and the luminescence effect is the best;

[0044] Fig. 9 :Luminescence photos based on NaYF4:Er upconversion nanomaterials under 980 / 1973nm near-infrared light synergistic excitation;

[0045] As can be seen from the figure, by fixing the excitation power of 980nm excitation light (200mW) and gradually increasing the excitation power of 1973nm excitation light (0-1200mW), in a single lanthanide Er 3+ Dynamic multicolor upconversion luminescence photos from green to yellow-green, yellow, orange, and finally red were achieved in ion-doped NaYF4 nanoparticles;

[0046] Fig.10 :Upconversion emission spectrum of NaYF4:Er upconversion nanomaterials under 980 / 1973nm near-infrared light synergistic excitation;

[0047] As can be seen from the figure, by fixing the excitation power of 980nm excitation light (200mW) and gradually increasing the excitation power of 1973nm excitation light (0-1200mW), in a single lanthanide Er 3+ Dynamic multicolor upconversion emission from green to yellow-green, yellow, orange, and finally red is achieved in ion-doped NaYF4 nanoparticles;

[0048] Fig.11 :CIE color coordinate diagram of multicolor upconversion emission based on NaYF4:Er upconversion nanomaterials under 980 / 1973nm near-infrared light synergistic excitation;

[0049] It can be seen from the figure that with the increase of 1973nm near-infrared light excitation power, in the single lanthanide Er 3+ Dynamic multicolor upconversion luminescence regulation from green to yellow-green, yellow, orange, and finally red is achieved in ion-doped NaYF4 nanoparticles;

[0050] Fig.12 :The relationship between the red / green upconversion luminescence intensity and the excitation power based on NaYF4:Er upconversion nanomaterials under the synergistic excitation of 980 / 1973nm near-infrared light;

[0051] As can be seen from the figure, both green and red emission under cooperative excitation conform to the two-photon upconversion process;

[0052] Fig.13 : Schematic diagram of the 980nm coupled 1973nm laser system of the present invention;

[0053] Fig.14 :(a) Schematic diagram of a three-dimensional color display system based on a 980nm coupled 1973nm laser cooperative excitation system equipped with a synchronous galvanometer scanning device;

[0054] (b) Photograph of the prepared three-dimensional display solid medium based on NaYF4:Er upconversion nanomaterial / epoxy resin AB glue composite material;

[0055] (c) Photograph of the prepared two-dimensional display solid medium based on NaYF4:Er upconversion nanomaterial / epoxy resin AB glue composite material;

[0056] (d) A three-dimensional color display solid medium display system using a hollow hexagonal prism to display a three-dimensional color stereoscopic image under the cooperative excitation of 980 / 1973nm near-infrared light;

[0057] (e) A color two-dimensional plane display image of the letter “Nano” under the synergistic excitation of 980 / 1973nm near-infrared light by a display system based on a two-dimensional color display solid medium;

[0058] (f) The display system based on two-dimensional color display solid medium shows a colorful two-dimensional plane display image of the letters "UCNPs" under the synergistic excitation of 980 / 1973nm near-infrared light. DETAILED DESCRIPTION

[0059] In order to clearly and completely describe the technical solution and its specific working process of the present invention, the specific implementation methods of the present invention are as follows in conjunction with the accompanying drawings of the specification:

[0060] Example 1

[0061] This embodiment provides a single lanthanide Er 3+ Ion excited state population regulation to achieve multicolor upconversion luminescence display system, including single lanthanide Er 3+A three-dimensional / two-dimensional color solid display matrix of ion-doped NaYF4 nanoparticles / polymer composite materials, an optical lens group, a 980 / 1973nm cooperative excitation laser system and a laser scanner. The optical lens group includes a laser collimator lens and a telephoto lens; the 980 / 1973nm cooperative excitation laser system is formed by coupling a 980nm near-infrared continuous laser and a 1973nm near-infrared continuous laser through a wavelength division multiplexer; the optical lens group specifically includes a laser collimator lens with a focal length range of 5 to 25 mm and a telephoto lens with a focal length range of 3 to 15 cm. The display system outputs image data through 3D modeling software, uses a laser scanner main controller to receive signals, uses a 980nm coupled 1973nm near-infrared laser system as a pump source, and converges the coupled two laser beams through a telephoto lens at a fixed point in the three-dimensional / planar space of a three-dimensional / two-dimensional color solid display matrix. By fixing the excitation power of the 980nm excitation light (200mW) and gradually increasing the excitation power of the 1973nm excitation light (0-1200mW), dynamic multi-color up-conversion luminescence regulation from green to yellow-green, yellow, orange, and finally red is achieved in the NaYF4:Er up-conversion nanomaterial; by programmatically controlling the laser convergence point to scan in the color solid display matrix in three directions of X, Y, and Z axes, by adjusting the excitation power of the 980 / 1973nm co-excitation and utilizing the persistence effect of human vision, a color three-dimensional display image composed of countless nano-body pixels can be obtained.

[0062] In this embodiment, the color solid display matrix is ​​composed of NaYF4:Er (8%) upconversion nanomaterials as the luminescent medium; polymer materials as the three-dimensional display solid medium; a three-dimensional / two-dimensional color solid display matrix based on NaYF4:Er / polymer composite materials with high transparency is prepared by doping or copolymerization; wherein the polymer material is epoxy resin AB glue, polymethyl methacrylate or polydimethylsiloxane.

[0063] The working principle of a display system based on NaYF4:Er upconversion nanomaterials in this embodiment is as follows:

[0064] The display system of this embodiment uses a 980nm coupled 1973nm near-infrared laser system as a pump source; the two coupled laser beams are converged at a fixed point in the three-dimensional / two-dimensional color solid display matrix through a telephoto lens, and the excitation power of the 980nm excitation light is fixed (200mW) and the excitation power of the 1973nm excitation light is gradually increased (0-1200mW), so that dynamic multi-color up-conversion luminescence control light from green to yellow-green, yellow, orange, and finally red is realized in the NaYF4:Er up-conversion nanomaterial; due to NaYF4:Er upconversion luminescent nanomaterials are distributed in the spatial area of ​​the three-dimensional display solid medium. Through selective fixed-point excitation, upconversion luminescence can be generated inside the three-dimensional display solid medium. The nanocrystal at the fixed-point luminescent position is equivalent to a nanobody pixel point. Through programmed control of the laser convergence point, scanning in the three directions of X, Y, and Z axes in the color solid display matrix, by adjusting the excitation power of 980 / 1973nm co-excitation and utilizing the persistence effect of human vision, a color three-dimensional display image composed of countless nanobody pixels can be obtained.

[0065] The display system of this embodiment benefits from the lanthanide luminescence Er 3+ The ion-rich energy level structure and long-lived excited state energy level can achieve Er by changing the 980 / 1973nm cooperative excitation wavelength and power. 3+ Green light emitting level 2 H 11 / 2 / 4 S 3 / 2 To the red emission level 4 F 9 / 2 The regulation of two different upconversion processes can be achieved, and finally in a single lanthanide Er 3+ Multicolor upconversion luminescence is achieved in ion-doped NaYF4 nanomaterials. Hexagonal β-NaYF4 is selected as the matrix material in this nanomaterial because it has lower phonon energy and can weaken Er 3+ The radiationless relaxation process of ions improves the upconversion luminescence; the single lanthanide luminescent Er is selected 3+ Ions act as sensitizers to absorb the energy of 980nm and 1973nm near-infrared light in turn; at the same time, the Er 3+ The ions act as activators to produce two different upconversion processes based on the energy level distribution of green and red excited states; by fixing the excitation power of 980nm excitation light (200mW) and gradually increasing the excitation power of 1973nm excitation light (0-1200mW), the single lanthanide Er 3+ Dynamic multicolor upconversion luminescence regulation from green to yellow-green, yellow, orange, and finally red was achieved in ion-doped NaYF4 nanomaterials.

[0066] Example 2

[0067] This embodiment provides a method for preparing a color solid display matrix, which specifically includes the following steps:

[0068] Step 1: Preparation of NaYF4:Er (8%) upconversion nanomaterials:

[0069] Take a 50mL two-necked round-bottom flask as a reaction container, add 3mL oleic acid and 7mL octadecene to a predetermined ratio of 0.4mmol of Y(CH3COO)3 (92%) and Er(CH3COO)3 (8%) aqueous solution, stir the resulting mixture at 150°C for 60 minutes to remove water and low-boiling solvent molecules to form an oleic acid complex precursor. After the resulting mixture is cooled to room temperature, add 4mL NH4F (0.4moL / L) and 2mL NaOH (0.5moL / L) methanol solution and heat to 50°C and stir continuously for 30 minutes, then heat to 100°C and keep under vacuum for 10 minutes to remove methanol, then heat to 290°C under inert gas protection for 90 minutes. After the reaction is completed, the mixture is cooled to room temperature, and the prepared nanoparticles are precipitated by centrifugation, and then washed repeatedly with cyclohexane and ethanol for several times, and finally the product is dispersed in cyclohexane to prepare NaYF4:Er (8%) upconversion nanomaterials;

[0070] Step 2: Prepare a color solid display matrix by doping or copolymerization:

[0071] The cyclohexane solution containing NaYF4:Er nanoparticles (90 mg) was dispersed in 7.5 mL of epoxy resin (component A), stirred at room temperature for 20 minutes, and then 3 mL of curing agent (component B) was added and stirred at room temperature for 30 minutes. After being fully mixed, the mixture was centrifuged for 5 minutes to remove bubbles, and then poured into a silica gel mold and heated to 50°C in a vacuum drying oven for curing for 48 hours. After cooling to room temperature, demolding was performed to obtain a nanomaterial / epoxy resin AB glue composite color solid display matrix.

[0072] Example 3

[0073] This embodiment provides a single lanthanide Er 3+The invention discloses a display method for a display system that realizes multicolor upconversion luminescence by regulating the distribution of ion excited states. Specifically, a 980nm coupled 1973nm near-infrared laser system is used as a pump source; the two coupled laser beams are converged at a fixed position in the three-dimensional / two-dimensional space of a three-dimensional / two-dimensional color solid display matrix through a telephoto lens; by fixing the excitation power (200mW) of the 980nm excitation light and gradually increasing the excitation power (0-1200mW) of the 1973nm excitation light, dynamic multicolor upconversion luminescence regulation light from green to yellow-green, yellow, orange, and finally red is realized in the NaYF4:Er upconversion nanomaterial; the nanocrystal at the fixed luminescence position is equivalent to a nanobody pixel point, and a color three-dimensional display image composed of countless nanobody pixels can be obtained by performing fast three-dimensional addressing scanning of a stereoscopic image through a laser scanner.

[0074] The display method specifically comprises the following steps:

[0075] By adjusting the excitation power of 980 / 1973nm co-excitation, Figure 3 The prepared NaYF4:Er (8%) upconversion nanomaterials can produce multi-color upconversion luminescence, such as Fig. 9 As shown;

[0076] Specifically, by adjusting the excitation power of the two laser beams, dynamic multi-color up-conversion luminescence regulation from green to yellow-green, yellow, orange, and finally red can be achieved; the specific regulation scheme is as follows:

[0077] When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 0mW, green upconversion luminescence is generated;

[0078] When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 220mW, yellow-green upconversion luminescence is generated;

[0079] When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 460mW, yellow up-conversion luminescence is generated;

[0080] When the power of the 980nm laser is 200mW and the power of the 1973nm laser is 620mW, orange upconversion luminescence is generated;

[0081] When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 1200mW, red up-conversion luminescence is generated.

[0082] Will Figure 3The prepared NaYF4:Er (8%) upconversion nanomaterial is dispersed into a transparent three-dimensional display solid medium (epoxy resin AB glue, polymethyl methacrylate or polydimethylsiloxane) by doping or copolymerization to obtain a three-dimensional / two-dimensional color solid display matrix, such as Fig.14 (b) (c)

[0083] By building a three-dimensional color display system, such as Fig.14 As shown in (a), 3D modeling software is used to output image data; a laser scanner main controller is used to receive signals; a 980nm coupled 1973nm near-infrared laser system is used as a pump source; the two coupled laser beams are converged at a fixed position in the three-dimensional / two-dimensional space of the color solid display matrix through a telephoto lens, and by fixing the excitation power of the 980nm excitation light (200mW) and gradually increasing the excitation power of the 1973nm excitation light (0-1200mW), a dynamic multi-color up-conversion luminescence control light from green to yellow-green, yellow, orange, and finally red is realized in the NaYF4:Er up-conversion nanomaterial; the laser convergence point is programmed by the laser scanner to scan in the three directions of the X, Y, and Z axes in the color solid display matrix, and by adjusting the excitation power of the 980 / 1973nm co-excitation and using the persistence effect of human vision, a color three-dimensional display image composed of countless nano-body pixels can be obtained, as shown in FIG. Fig.14 As shown in (d)(e)(f).

[0084] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0085] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0086] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A single lanthanide Er-based 3+ A display system for realizing multicolor upconversion luminescence by regulating the population of ion excited states, characterized in that: Including based on a single lanthanide Er 3+ A three-dimensional / two-dimensional color solid display matrix of ion-doped NaYF4 nanoparticle / polymer composite material, an optical lens group, a 980 / 1973nm cooperative excitation laser system and a laser scanner; the optical lens group includes a laser collimating lens and a telephoto lens; the 980 / 1973nm cooperative excitation laser system is formed by coupling a 980nm near-infrared continuous laser and a 1973nm near-infrared continuous laser through a wavelength division multiplexer; the two coupled laser beams are converged at a fixed point position in the three-dimensional / planar space of the three-dimensional / two-dimensional color solid display matrix through a telephoto lens, and color display imaging is performed by adjusting the excitation power of the 980 / 1973nm cooperative excitation and using a laser scanner; the laser scanner is used to control the laser convergence point to scan in the three directions of the X, Y and Z axes in the color solid display matrix according to the set three-dimensional image data, and a color three-dimensional display image composed of countless nano-body pixel points can be obtained by adjusting the excitation power of the 980 / 1973nm cooperative excitation and using the persistence effect of human eye vision.

2. A method based on a single lanthanide Er as claimed in claim 1. 3+ A display system for realizing multicolor upconversion luminescence by regulating the population of ion excited states, characterized in that: The focal length of the laser collimating lens is 5-25 mm, and the focal length of the telephoto lens is 3-15 cm.

3. A method based on single lanthanide Er as claimed in claim 1. 3+ A display system for realizing multicolor upconversion luminescence by regulating the population of ion excited states, characterized in that: The three-dimensional / two-dimensional color solid display matrix is ​​a three-dimensional / two-dimensional color solid display matrix based on NaYF4:Er / polymer composite material with high transparency, which is prepared by doping or copolymerization with NaYF4:Er upconversion nanomaterials as luminescent media and polymer materials as three-dimensional display solid media.

4. A method based on a single lanthanide Er as claimed in claim 3 3+ A display system for realizing multicolor upconversion luminescence by regulating the population of ion excited states, characterized in that: The polymer material is epoxy resin AB glue, polymethyl methacrylate or polydimethylsiloxane.

5. A method based on single lanthanide Er as claimed in claim 1 3+ A display system for realizing multicolor upconversion luminescence by regulating the population of ion excited states, characterized in that: The single lanthanide Er 3+ The ion-doped NaYF4 nanoparticles are prepared by a thermal coprecipitation method, which specifically comprises the following steps: A 50 mL two-necked round-bottom flask was used as a reaction container, and 3 mL of oleic acid and 7 mL of octadecene were added to an aqueous solution of Y(CH3COO)3 and Er(CH3COO)3 in a predetermined ratio with a total amount of 0.4 mmol. The resulting mixture was stirred at 150°C for 60 minutes to remove water and low-boiling solvent molecules to form an oleic acid complex precursor; after the resulting mixture was cooled to room temperature, 4 mL of NH4F and 2 mL of NaOH methanol solution were added and the temperature was raised to 50°C and stirred continuously for 30 minutes, then the temperature was raised to 100°C and maintained under vacuum conditions for 10 minutes to remove methanol, and then the temperature was raised to 290°C under inert gas protection for 90 minutes; after the reaction was completed, it was cooled to room temperature, the prepared nanoparticles were precipitated by centrifugal separation, and then washed repeatedly with cyclohexane and ethanol several times, and finally the product was dispersed in cyclohexane.

6. A method based on single lanthanide Er as claimed in claim 1 3+ A display system for realizing multicolor upconversion luminescence by regulating the population of ion excited states, characterized in that: The single lanthanide Er 3+ The preparation method of the three-dimensional / two-dimensional color solid display matrix of ion-doped NaYF4 nanoparticles / polymer composite material comprises the following specific steps: The cyclohexane solution containing NaYF4:Er nanoparticles was dispersed in the epoxy resin, stirred at room temperature for 20 minutes, and then the curing agent was added and stirred at room temperature for 30 minutes; the volume ratio of the nanoparticle cyclohexane solution to the epoxy resin and the curing agent was 1:2.5:1; after being fully mixed, the mixture was centrifuged for 5 minutes to remove bubbles, and then poured into a silicone mold and heated to 50°C in a vacuum drying oven for curing for 48 hours, and then demolded after cooling to room temperature to obtain a nanomaterial / epoxy resin AB glue composite color solid display matrix.

7. A method based on single lanthanide Er as claimed in claim 1. 3+ A display method for a display system that realizes multicolor up-conversion luminescence by regulating the population of ion excited states, characterized in that: The specific steps include: Step 1: Combine NaYF4:Er nanomaterials with epoxy resin AB glue by doping or copolymerization, pour into silicone molds of various geometric shapes for curing, and prepare a color display matrix based on nanocrystal / polymer composite materials with high transparency; Step 2: A laser system formed by coupling a 980nm near-infrared continuous laser and a 1973nm near-infrared continuous laser through a wavelength division multiplexer is used as a pump source, and the coupled laser is focused at a fixed point in the three-dimensional / two-dimensional color solid display matrix through a telephoto lens; Step 3: Output image data through 3D modeling software, use the laser scanner main controller to receive signals, control the laser convergence point to scan in the color solid display matrix in the X, Y, and Z axis directions, and obtain a color three-dimensional display image composed of countless nano-body pixels by adjusting the excitation power of 980 / 1973nm co-excitation and utilizing the persistence effect of human vision.

8. A method based on a single lanthanide Er as claimed in claim 7. 3+ A display method for a display system that realizes multicolor up-conversion luminescence by regulating the population of ion excited states, characterized in that: The excitation power of the 980 / 1973nm cooperative excitation is adjusted by fixing the excitation power of the 980nm excitation light at 200mW and gradually increasing the excitation power of the 1973nm excitation light in the range of 0-1200mW, thereby realizing dynamic multi-color upconversion luminescence regulation from green to yellow-green, yellow, orange, and finally red in the NaYF4:Er upconversion nanomaterial.

9. A method based on a single lanthanide Er as claimed in claim 8 3+ A display method for a display system that realizes multicolor up-conversion luminescence by regulating the population of ion excited states, characterized in that: The specific control method for adjusting the excitation power of 980 / 1973nm cooperative excitation includes the following contents: When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 0mW, green upconversion luminescence is generated; When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 220mW, yellow-green upconversion luminescence is generated; When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 460mW, yellow up-conversion luminescence is generated; When the power of the 980nm laser is 200mW and the power of the 1973nm laser is 620mW, orange upconversion luminescence is generated; When the excitation power of the 980nm laser is 200mW and the excitation power of the 1973nm laser is 1200mW, red up-conversion luminescence is generated.

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