Microcavity-enhanced quantum dot transcolor structure and its preparation method

Abstract

This invention relates to a microcavity-enhanced quantum dot color conversion structure, comprising a substrate, a first reflective layer, a blue emitting layer, a quantum dot conversion layer, and a second reflective layer stacked sequentially. The blue emitting layer emits blue light, and the quantum dot conversion layer converts the blue light into red or green light. A microcavity structure is formed between the first and second reflective layers, creating stable blue and red light resonance conditions within the microcavity structure. Light is reflected within the microcavity structure to form blue and red standing waves. In the thickness direction, the blue emitting layer is located at the peak of the blue standing wave, and the quantum dot conversion layer is located at the overlap of the peaks of the red and blue standing waves. The blue excitation material and the red and green quantum dots are all located in the region of strongest light field, enhancing the excitation efficiency of blue light and simultaneously increasing the luminous intensity of red light; similarly, it also enhances the luminous intensity of green light, thereby effectively improving the color conversion efficiency of the quantum dot conversion layer.

Description

Technical Field

[0001] This invention relates to the field of full-color display technology, and in particular to a microcavity enhanced quantum dot color conversion structure and its preparation method. Background Technology

[0002] In display technology, especially in the field of Mini-LED / Micro-LED full-color displays, quantum dots are widely used as a highly efficient color conversion material. Quantum dots (QDs) exhibit unique advantages in light-emitting and display applications due to their high color purity, tunable emission color, high fluorescence quantum yield, and excellent stability. Traditional quantum dot color conversion typically employs methods such as inkjet printing and photolithography; however, these methods show limitations in high-resolution displays and small-sized pixels, making it difficult to meet the ever-increasing demands for display performance.

[0003] To improve the color conversion efficiency of quantum dots, researchers have introduced microcavity structures. The resonant characteristics of microcavities can enhance the light field, strengthening it at specific frequencies and thus improving the luminous efficiency and color purity of quantum dots. However, existing microcavity enhancement structures have some problems. For example, uneven light field distribution may lead to uneven excitation efficiency of quantum dots, affecting the overall color conversion effect. Furthermore, quantum dots are prone to photodegradation under high-intensity light excitation, affecting the lifespan and performance stability of displays. This phenomenon is particularly pronounced under high-resolution and high-brightness display requirements. Therefore, optimizing the intensity distribution of blue light in microcavity structures and rationally designing the distribution of quantum dots and the position of the light field to improve color conversion efficiency, uniformity, and device stability have become key technical challenges that need to be addressed. Summary of the Invention

[0004] The present invention provides a microcavity-enhanced quantum dot color conversion structure and its preparation method. By optimizing the intensity distribution of blue light in the microcavity and rationally designing the distribution of quantum dots and the position of the light field, the color conversion efficiency, uniformity and stability of the microcavity-enhanced quantum dot color conversion structure are improved.

[0005] First aspect

[0006] This invention discloses a microcavity-enhanced quantum dot color conversion structure, comprising a substrate, a first reflective layer, a blue emitting layer, a quantum dot conversion layer, and a second reflective layer stacked sequentially. The blue emitting layer emits blue light, and the quantum dot conversion layer can convert the blue light into red or green light. A microcavity structure is formed between the first reflective layer and the second reflective layer. The first reflective layer and the second reflective layer are configured to form stable resonance conditions for blue and green light or stable resonance conditions for blue and red light in the microcavity structure.

[0007] In this configuration, light is reflected within the microcavity structure to form blue and red standing waves. Along the length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave; the quantum dot conversion layer is located at the overlap of the peaks of the red and blue standing waves. Alternatively, light is reflected within the microcavity structure to form blue and green standing waves. Along the length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave; the quantum dot conversion layer is located at the overlap of the peaks of the green and blue standing waves.

[0008] In one embodiment, the microcavity-enhanced quantum dot color conversion structure includes a first isolation layer, which is stacked between the quantum dot conversion layer and the blue emitting layer along the cavity length extension direction of the microcavity structure; and / or,

[0009] The microcavity-enhanced quantum dot color conversion structure includes a second isolation layer, which is stacked and disposed between the quantum dot conversion layer and the second reflection layer along the cavity length extension direction of the microcavity structure.

[0010] In one embodiment, both the first reflective layer and the second reflective layer are DBR reflective layers.

[0011] In one embodiment, the blue emitting layer includes an n-electrode, an n-GaN, a blue light multi-quantum well layer, a p-GaN, and a p-electrode stacked sequentially, wherein the blue light multi-quantum well emits the blue light; the n-electrode is stacked on the first reflective layer, and the p-electrode is stacked on the quantum dot conversion layer.

[0012] In one embodiment, the quantum dot conversion layer includes red quantum dots for converting blue light into red light, and the cavity length of the microcavity structure is an integer multiple of both the half-wavelength of the blue light and the half-wavelength of the red light; and / or, the quantum dot conversion layer includes green quantum dots for converting blue light into green light, and the cavity length of the microcavity structure is designed to be an integer multiple of both the half-wavelength of the blue light and the half-wavelength of the green light.

[0013] In one embodiment, the color-transfer structure of the microcavity enhanced quantum dot includes a black glue filling layer, which covers the periphery of the color-transfer structure of the microcavity enhanced quantum dot.

[0014] Second aspect

[0015] This invention discloses an application of a microcavity enhanced quantum dot color conversion structure, which applies the microcavity enhanced quantum dot color conversion structure described in any of the preceding embodiments to Mini-LED / Micro-LED full-color display devices.

[0016] Third aspect

[0017] This invention discloses a method for preparing a microcavity-enhanced quantum dot color-changing structure, comprising the following steps:

[0018] A first reflective layer is deposited, a substrate is prepared, and the first reflective layer is stacked on one side of the substrate;

[0019] A blue light-emitting layer is deposited, the blue light-emitting layer is prepared and processed and stacked on the side of the first reflective layer away from the substrate, and the blue light-emitting layer emits blue light;

[0020] A quantum dot conversion layer is deposited and stacked on one side of the blue light-emitting layer, which can convert the blue light into red or green light.

[0021] A second reflective layer is deposited, and the second reflective layer is stacked on the side of the quantum conversion layer opposite to the blue light-emitting layer.

[0022] A microcavity structure is formed between the first reflective layer and the second reflective layer, and the first reflective layer and the second reflective layer are configured to form stable resonance conditions for blue light and green light or stable resonance conditions for blue light and red light in the microcavity structure.

[0023] In this configuration, light is reflected within the microcavity structure to form blue and red standing waves. Along the length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave, and the quantum dot conversion layer is located at the overlap of the peaks of the red and blue standing waves. Alternatively, light is reflected within the microcavity structure to form blue and green standing waves. Along the length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave, and the quantum dot conversion layer is located at the overlap of the peaks of the green and blue standing waves.

[0024] In one embodiment, prior to the step of depositing the quantum dot conversion layer, a first isolation layer is fabricated and stacked on the light-emitting surface of the blue light-emitting layer, and microcavity structures with different cavity lengths are obtained by spin-coating the first isolation layer of different thicknesses; and / or, prior to the step of depositing the second reflective electrode, a second isolation layer is fabricated and stacked on the light-emitting surface of the quantum dot conversion layer, and microcavity structures with different cavity lengths are obtained by spin-coating the second isolation layer of different thicknesses.

[0025] In one embodiment, in the step of depositing the first reflective layer, a multilayer high and low refractive index dielectric material is deposited on one side of the substrate using electron beam luminescence to form a DBR reflective layer as the first reflective layer; and / or, in the step of depositing the second reflective layer, a multilayer high and low refractive index dielectric material is deposited on the side of the quantum dot conversion layer opposite to the blue light-emitting layer using electron beam luminescence to form a DBR reflective layer as the second reflective layer.

[0026] As can be seen from the above technical solutions, the embodiments of the present invention have at least the following advantages and positive effects:

[0027] This invention provides a microcavity-enhanced quantum dot color conversion structure. A microcavity structure is formed between a first reflective layer and a second reflective layer, creating a high-reflectivity region. Stable blue and red light resonates within the microcavity structure, and the reflected light forms blue and red standing waves. Along the cavity length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave, and the quantum dot conversion layer is located at the overlap of the peaks of the red and blue standing waves. Both the blue excitation material and the red and green quantum dots are located in the region of strongest light field, enhancing the excitation efficiency of blue light and simultaneously increasing the luminous intensity of red light; similarly, the luminous intensity of green light is also enhanced, thereby effectively improving the color conversion efficiency of the quantum dot conversion layer. This microcavity-enhanced quantum dot color conversion structure can be applied to Mini-LED / Micro-LED full-color display devices to improve their optical performance.

[0028] On the other hand, this application provides a method for fabricating a microcavity-enhanced quantum dot color conversion structure. The design of this microcavity structure ensures optimized distribution of the light field within the cavity, enabling effective enhancement and feedback of blue and red-green light within the same microcavity. Through reasonable cavity length and material selection, the microcavity structure not only significantly improves the light conversion efficiency of quantum dots but also reduces light leakage and crosstalk, resulting in a purer and more stable display effect. Compared to traditional display technologies with fixed structures, this application offers greater design flexibility and can be widely applied to various display needs. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the overall structure of a microcavity-enhanced quantum dot color-conversion structure according to an embodiment of this application;

[0031] Figure 2 A schematic diagram of the structure for converting blue light to red light;

[0032] Figure 3 A schematic diagram showing the distribution of blue and red standing waves in a microcavity structure for converting blue light to red light;

[0033] Figure 4 A schematic diagram of the blue-to-green color conversion structure;

[0034] Figure 5 This is a schematic diagram of the standing wave mode distribution of different colors of light in a microcavity structure.

[0035] Figure 6 This is a spectral diagram of the microcavity structure formed by the TiO2 / SiO2 DBR reflective layer in this application;

[0036] Figure 7 This is a flowchart of the preparation process for the color-transfer structure.

[0037] The annotations in the attached figures are explained as follows:

[0038] 10. Color conversion structure; 100. Substrate; 101. Microcavity structure; 200. First reflective layer; 300. Blue light-emitting layer; 310. n-electrode; 320. n-GaN; 330. Blue light multi-quantum well layer; 340. p-GaN; 350. p-electrode; 400. Quantum dot conversion layer; 410. Red quantum dot; 420. Green quantum dot; 500. Second reflective layer; 205. DBR reflective layer; 600. Isolation layer; 610. First isolation layer; 620. Second isolation layer; 700. Black glue filling layer. Detailed Implementation

[0039] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0040] 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 one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "setup," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] refer to Figure 1 This application provides a microcavity enhanced quantum dot color conversion structure 10 (hereinafter referred to as: color conversion structure 10). The color conversion structure 10 is a hierarchical structure including a substrate 100, a first reflective layer 200, a blue light-emitting layer 300, a quantum dot conversion layer 400 and a second reflective layer 500 stacked sequentially. The blue light-emitting layer 300 emits blue light, and the quantum dot conversion layer 400, as a color conversion layer, can convert blue light into red light or green light. A microcavity structure 101 is formed between the first reflective layer 200 and the second reflective layer 500. The vertical distance between the first reflective layer 200 and the second reflective layer 500 along the thickness direction of the hierarchical structure is the cavity length of the microcavity structure 101.

[0043] Reference Figure 2 and Figure 3 In one embodiment, the quantum dot conversion layer 400 includes a red quantum dot 410 for converting blue light into red light, and the first reflective layer 200 and the second reflective layer 500 are configured to form stable blue and red light resonance conditions in the microcavity structure 101. Figure 3 The diagram illustrates that light forms blue and red standing waves within the microcavity structure 101, with the peaks of the blue and red standing waves overlapping at specific locations within the microcavity structure. Along the cavity length of the microcavity structure 101, the blue emitting layer 300 is located at the peak of the blue standing wave, maximizing the light field intensity at this position and ensuring the luminous efficiency and excitation intensity of the blue light. The quantum dot conversion layer 400 converts blue light into red light. The quantum dot conversion layer 400, containing red quantum dots 410, is located at the overlapping peaks of the blue and red standing waves. Through the superposition of the standing waves at this location, the red quantum dots 410 absorb more blue light, achieving more efficient light conversion and improving the color conversion rate of the red quantum dots 410.

[0044] refer to Figure 4In one embodiment, the quantum dot conversion layer 400 includes green quantum dots 420, which convert blue light into green light. The first reflective layer 200 and the second reflective layer 500 are configured to form stable resonance conditions for blue and green light in the microcavity structure 101. The light forms blue and green standing waves in the microcavity structure 101, and the peaks of the blue and red standing waves overlap at specific locations within the microcavity structure. Along the cavity length of the microcavity structure 101, the blue emitting layer 300 is located at the peak of the blue standing wave, where the light field intensity is maximized, ensuring the luminous efficiency and excitation intensity of the blue light. The quantum dot conversion layer 400 can convert blue light into green light. The quantum dot conversion layer 400 with green quantum dots 420 is located at the position where the peaks of the blue light standing wave and the green light standing wave overlap. Through the superposition of the standing waves of blue light and red light wavelengths at this position, the red quantum dot 410 can absorb more blue light, thereby achieving more efficient light conversion and improving the color conversion rate of the green quantum dot.

[0045] In one embodiment, the first reflective layer 200 and the second reflective layer 500 are configured to simultaneously form stable blue and red light, and stable blue and green light resonance conditions within the microcavity structure 101. The light forms blue, red, and green standing waves within the microcavity structure 101, and the peaks of the blue and red or green standing waves can overlap at specific locations within the same microcavity structure 101. Along the cavity length of the microcavity structure 101, the blue emitting layer 300 is located at the peak of the blue standing wave, and the quantum dot conversion layer 400 can be located either at the overlap of the peaks of the blue and red standing waves, or at the overlap of the peaks of the blue and green standing waves, depending on the color conversion requirements. That is, the same color conversion structure 10 can achieve both blue-to-red and blue-to-green color conversion functions.

[0046] It should be noted that for structures that do not require color conversion, i.e., only need to emit blue light, it is only necessary to form a stable blue light standing wave in the microcavity structure 101 and place the blue light-emitting layer 300 at the peak of the blue light standing wave to enhance the excitation efficiency of blue light and improve the light efficiency and intensity.

[0047] Preferably, in one embodiment, in the blue-to-red light conversion structure 10, the stable resonance conditions for blue and red light can be satisfied, and the cavity length of the microcavity structure 101 is simultaneously equal to an integer multiple of the half wavelength of blue light and the half wavelength of red light, as shown in formula (1).

[0048] L = 1 / 2.n.λ B =1 / 2.m.λ R............................................ (1)

[0049] In the formula, L is the cavity length of the microcavity structure 101; n and m are both positive integers; λ BThe wavelength of blue light; λ R The wavelength is red light; the unit of each parameter is nm. In one embodiment, the blue light wavelength is 400 nm, the red light wavelength is 600 nm, and the cavity length L of the microcavity structure 101 is designed to be an integer multiple of 600 nm (which is the least common multiple of the half wavelength of blue light and the half wavelength of red light), so that stable resonance conditions of blue light and red light can be formed in the microcavity structure 101.

[0050] Preferably, in one embodiment, in the blue-to-green light conversion structure 10, the resonance conditions for forming stable blue and green light can be satisfied, and the cavity length of the microcavity structure 101 is simultaneously equal to an integer multiple of the half wavelength of blue light and the half wavelength of green light, as shown in formula (2).

[0051] L = 1 / 2.n.λ B =1 / 2.m.λ G............................................ (2)

[0052] In the formula, L is the cavity length of the microcavity structure 101; n and m are both positive integers; λ B The wavelength of blue light; λ G The wavelength is green light; all parameters are in nm.

[0053] Preferably, in one embodiment, in the color conversion structure 10 that simultaneously satisfies blue light to red light and blue light to green light, the cavity length of the microcavity structure 101 is equal to an integer multiple of the half wavelength of blue light, the half wavelength of red light and the half wavelength of green light, as shown in formula (3).

[0054] L = 1 / 2.n.λ B =1 / 2.m.λ R =1 / 2.i.λ G............................................ (3)

[0055] In the formula, L is the cavity length of the microcavity structure 101; n, m, and i are all positive integers; λ B The wavelength of blue light; λ R λ is the wavelength of red light. G The wavelength is green light; the unit of each parameter is nm. The cavity length L of the microcavity structure 101 is equal to the smallest integer multiple of the half wavelength of blue light and the half wavelength of green light.

[0056] refer to Figure 5The cavity length L of the aforementioned microcavity structure 101 is set to an integer multiple of the half-wavelength of different light waves. This ensures that light of different color wavelengths forms a stable standing wave distribution within the microcavity structure 101. Placing the luminescent material layer at the peak of the corresponding standing wave, i.e., the position of strongest light field, improves luminous efficiency. It should be noted that the cavity length of the microcavity structure 101 is not limited to an integer multiple of the half-wavelength of the light wave. Any principle or formula ensuring a stable standing wave distribution of light of different color wavelengths within the microcavity structure 101 should be within the scope of this application.

[0057] Preferably, refer to Figure 1 In one embodiment, the color-transfer structure 10 includes an isolation layer 600 (spacer), which includes a first isolation layer 610. The first isolation layer 610 is stacked and disposed between the quantum dot conversion layer 400 and the blue light-emitting layer 300 along the cavity length extension direction of the microcavity structure 101. The color-transfer structure 10 also includes a second isolation layer 620, which is stacked and disposed between the quantum dot conversion layer 400 and the second reflective layer 500 along the cavity length extension direction of the microcavity structure 101.

[0058] It should be noted that, in this application, the isolation layer 600 serves two purposes. First, it protects the functional hierarchical structure in the color-conversion structure 10 from damage during processing and deposition, or from mutual erosion due to direct contact between functional layers. The first isolation layer 610 protects the blue emitting layer 300 from damage during the processing and deposition of the quantum dot conversion layer 400, and the second isolation layer 620 protects the quantum dot conversion layer 400 from damage during the processing and deposition of the second electrode layer. Second, the isolation layer 600 provides necessary mechanical support for the microcavity structure 101. Moreover, by adjusting the thickness of the isolation layer 600, the cavity length of the microcavity structure 101 can be changed, thereby altering the optical performance of the microcavity structure 101. Of course, in other embodiments, the cavity length of the microcavity structure 101 can also be changed by altering the thickness of other functional layers in the color-conversion structure 10, but this is more difficult to achieve. In addition, the material of the isolation layer 600 is selected from inorganic inert materials such as silicon dioxide, silicon nitride, alumina, and silicon carbide, which have advantages such as good optical transparency, chemical stability, insulation, and mechanical properties. It is understood that in this application, the presence or absence of a first isolation layer 610 is not limited. In this application, it is sufficient to achieve the condition that the microcavity structure 101 enhances the color conversion rate of the quantum dot conversion layer 400, that is, a stable standing wave is formed in the microcavity structure 101, the blue light emitting layer 300 is located at the peak of the blue light standing wave, and the quantum dot conversion layer 400 is located at the position where the peak of the blue light standing wave overlaps with the peaks of the red and green standing waves.

[0059] Preferably, in one embodiment, in conjunction with reference to Figure 1 and Figure 6Both the first reflective layer 200 and the second reflective layer 500 are DBR reflective layers 205 (Bragg emission mirrors). The microcavity structure 101 forms a high-reflection area with the upper and lower DBR reflective layers 205 to ensure efficient light feedback. Here, the DBR reflective layer 205 is composed of multiple layers of high and low refractive index TiO2 / SiO2 stacked together. The refractive index of TiO2 is 2.5, the refractive index of SiO2 is 1.45, and the refractive index inside the microcavity structure 101 is 1.8. Figure 6 This illustrates that the width of the high-reflectivity region between the upper and lower DBR reflective layers 205 can reach 200 nm, effectively reflecting light and forming a high-quality light field. Furthermore, the DBR reflective layer 205 can stably form resonance conditions for blue and red-green light without considering changes in refractive index with wavelength. This embodiment uses a distributed Bragg reflector (DBR) composed of TiO2 / SiO2 as the high-reflectivity region, combined with a precisely adjusted cavity length gauge, enabling it to adapt to light sources of different wavelengths, especially the coexistence of blue and red-green light. The high reflectivity of the DBR ensures multiple optical feedbacks within the microcavity structure 101, thereby achieving targeted enhanced feedback for different wavelengths.

[0060] It should be noted that in this application, the first reflective layer 200 and the second reflective layer 500 are not necessarily DBR reflective layer 205. Any reflective layer (such as a metal mirror) that can form a high reflective area and create stable resonance conditions for blue and red-green light inside the microcavity structure 101 should be included. In addition, the material selection for the DBR reflective layer 205 is not limited to TiO2 / SiO2; other high and low refractive index material layers such as Ta2O5 / SiO2 and HfO2 / SiO2 can also be selected.

[0061] Preferably, refer to Figure 1 In one embodiment, the blue light-emitting layer 300 uses a commercially available blue LED, including an n-electrode 310, an n-GaN 320, a blue light-emitting multi-quantum-well layer 330, a p-GaN 340, and a p-electrode 350 stacked sequentially. The blue light-emitting multi-quantum-well layer 330 emits blue light. One of the n-electrode 310 and the p-electrode 350 is stacked on the first reflective layer 200, and the other is stacked on the quantum dot conversion layer 400. If a first isolation layer 610 is provided, the other is stacked on the first isolation layer 610. It should be noted that in this application, the blue light-emitting layer 300 does not necessarily use a blue LED; any layered material structure capable of emitting blue light is within the scope of protection of this application.

[0062] Preferably, refer to Figure 1The color-transfer structure 10 includes a black adhesive filling layer 700, which covers the periphery of the layered structure of the color-transfer structure 10. The black adhesive filling layer 700 extends from the first reflective layer 200 to the second reflective layer 500, that is, the black adhesive filling layer 700 is disposed on the periphery of the microcavity structure 101. It should be noted that in this application, the presence or absence of the black adhesive filling layer 700 is not limited. In other embodiments, other passivation layers or buffer layers may also be used to fill and cover the periphery of the microcavity structure 101.

[0063] Secondly, this application provides an application of the microcavity-enhanced quantum dot color conversion structure 10, which is used in Mini-LED / Micro-LED full-color display devices. Here, a full-color display device can be formed simply by arranging multiple blue emitting layers 300, the blue-to-green color conversion structure 10, and the blue-to-red color conversion structure 10 in a simple RGB array. The microcavity structure 101 design in the color conversion structure 10 not only significantly improves the color conversion rate of the quantum dots and the performance of the full-color device, but also reduces light leakage and crosstalk, resulting in a purer and more stable display effect. The color conversion structure 10 can also be used to realize Resonant CavityLED devices or LaserDiode devices.

[0064] Thirdly, in conjunction with reference Figure 1 and Figure 7 This application also provides a method for preparing a microcavity enhanced quantum dot color-changing structure 10, comprising the following steps:

[0065] S10. Deposit the first reflective layer 200, prepare the substrate 100 as a substrate, and process and stack the first reflective layer 200 on one side of the substrate 100.

[0066] S20. Deposit a blue light-emitting layer 300. Prepare the blue light-emitting layer 300 and process and stack it on the side of the first reflective layer 200 away from the substrate 100. The blue light-emitting layer 300 emits blue light.

[0067] S30. Deposit quantum dot conversion layer 400. The quantum dot conversion layer 400 is processed and stacked on the side of the blue light-emitting layer 300 that emits light. The quantum dot conversion layer 400 can convert blue light into red light or green light.

[0068] S40, deposit the second reflective layer 500, and process and stack the second reflective layer 500 on the side of the quantum dot conversion layer 400 away from the blue light-emitting layer 300;

[0069] A microcavity structure 101 is formed between the first reflective layer 200 and the second reflective layer 500. The first reflective layer 200 and the second reflective layer 500 are configured to form stable resonance conditions for blue and green light, or stable resonance conditions for blue and red light, within the microcavity structure 101. Specifically, light forms blue and red standing waves in the microcavity structure 101. Along the cavity length of the microcavity structure 101, the blue emitting layer 300 is designed to be located at the peak of the blue standing wave, and the quantum dot conversion layer 400 is designed to be located at the overlap of the peaks of the red and blue standing waves. Alternatively, light forms blue and green standing waves in the microcavity structure 101. Along the cavity length of the microcavity structure 101, the blue emitting layer 300 is designed to be located at the peak of the blue standing wave, and the quantum dot conversion layer 400 is designed to be located at the overlap of the peaks of the green and blue standing waves.

[0070] Preferably, in one embodiment, before depositing the quantum dot conversion layer 400, a first isolation layer 610 is fabricated and stacked on the light-emitting surface of the blue light-emitting layer 300. Microcavity structures 101 with different cavity lengths are obtained by spin-coating the first isolation layer 610 of different thicknesses to adjust the optical performance of the microcavity structure 101. Of course, the first isolation layer 610 also protects the quantum dot conversion layer 400 from direct contact with the light-emitting surface of the blue light-emitting layer 300 during fabrication, thus preventing damage to the corresponding contact functional layer and providing protection for both the blue light-emitting layer 300 and the quantum dot conversion layer 400. Similarly, before depositing the second reflective layer 500, a second isolation layer 620 can be fabricated and stacked on the light-emitting surface of the quantum dot conversion layer 400. Microcavity structures 101 with different cavity lengths are obtained by spin-coating the second isolation layer 620 of different thicknesses to adjust the optical performance of the microcavity structure 101. The second isolation layer 620 can also protect the second reflective layer 500 from direct contact with the light-emitting surface of the quantum dot conversion layer 400 during the processing, thus preventing damage to the corresponding contact functional layer and playing a protective role for the quantum dot conversion layer 400 and the second reflective layer 500.

[0071] Preferably, in one embodiment, in the step of depositing the first reflective layer 200, a multilayer high- and low-refractive-index dielectric material is deposited on one side of the substrate 100 using electron beam luminescence to form a DBR reflective layer 205 as the first reflective layer 200. In the step of depositing the second reflective layer 500, a multilayer high- and low-refractive-index dielectric material is deposited on the side of the quantum dot conversion layer 400 opposite to the blue light-emitting layer 300, or on the side of the second isolation layer opposite to the quantum dot conversion layer 400, using electron beam luminescence to form a DBR reflective layer 205 as the first reflective layer 200. The high- and low-refractive-index dielectric materials here include, but are not limited to, TiO2 / SiO2. 2， Ta2O5 / SiO2, HfO2 / SiO2.

[0072] It should be noted that this application utilizes the vernier effect, that is, by precisely locating the peaks of the light field and the peaks of the standing waves, the blue emitting layer 300 is positioned at the peak of the blue light standing wave, while simultaneously searching for another peak of the blue light standing wave so that it coincides with the peaks of the red and green light standing waves. A quantum dot conversion layer 400 (red quantum dot 410 or green quantum dot 420) is placed at this overlapping position. Through this design, both the blue emitting layer 300 (blue emitting material) and the quantum dot conversion layer 400 (red and green emitting material) are located in the region of strongest light field, enhancing the excitation efficiency of blue light and also increasing the luminous intensity of red and green light, thereby effectively improving the color conversion rate of the quantum dot conversion layer 400.

[0073] This invention provides a microcavity-enhanced quantum dot color conversion structure 10. A microcavity structure 101 is formed between a first reflective layer 200 and a second reflective layer 500, creating a high-reflectivity region. Stable blue and red light resonance conditions are formed within the microcavity structure 101, and light is reflected within the microcavity structure 101 to form blue and red standing waves. Along the cavity length extension direction of the microcavity structure 101, the blue emitting layer 300 is located at the peak of the blue standing wave, and the quantum dot conversion layer 400 is located at the overlapping peaks of the red and blue standing waves. Both the blue excitation material and the red and green quantum dots are located in the region of strongest light field, enhancing the excitation efficiency of blue light and simultaneously increasing the luminous intensity of red light; similarly, it also enhances the luminous intensity of green light, thereby effectively improving the color conversion efficiency of the quantum dot conversion layer 400. This microcavity-enhanced quantum dot color conversion structure 10 can be applied to Mini-LED / Micro-LED full-color display devices to improve the optical performance of these devices.

[0074] On the other hand, this application provides a method for fabricating a microcavity-enhanced quantum dot color conversion structure 10. The design of this microcavity structure 101 ensures optimized distribution of the light field within the cavity, enabling effective enhancement feedback of blue light and red / green light within the same microcavity. Through reasonable cavity length and material selection, the microcavity structure 101 not only significantly improves the light conversion efficiency of quantum dots but also reduces light leakage and crosstalk, resulting in a purer and more stable display effect. Compared to traditional display technologies with fixed structures, this application offers greater design flexibility and can be widely applied to various display needs.

[0075] Although the invention has been described with reference to several typical embodiments, it should be understood that the terminology used is illustrative and exemplary, and not restrictive. Since the invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A microcavity-enhanced quantum dot color-shifting structure, characterized in that, The device comprises a substrate, a first reflective layer, a blue emitting layer, a quantum dot conversion layer, and a second reflective layer stacked sequentially. The blue emitting layer emits blue light, and the quantum dot conversion layer can convert the blue light into red or green light. A microcavity structure is formed between the first reflective layer and the second reflective layer. The quantum dot conversion layer includes red quantum dots used to convert blue light into red light. The cavity length of the microcavity structure is simultaneously equal to an integer multiple of both the half-wavelength of the blue light and the half-wavelength of the red light. Alternatively, the quantum dot conversion layer includes green quantum dots used to convert blue light into green light. The cavity length of the microcavity structure is designed to be simultaneously equal to an integer multiple of both the half-wavelength of the blue light and the half-wavelength of the green light. The first reflective layer and the second reflective layer are configured to form stable resonance conditions for blue and green light or stable resonance conditions for blue and red light within the microcavity structure. In this configuration, light is reflected within the microcavity structure to form blue and red standing waves. Along the length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave; the quantum dot conversion layer is located at the overlap of the peaks of the red and blue standing waves. Alternatively, light is reflected within the microcavity structure to form blue and green standing waves. Along the length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave; the quantum dot conversion layer is located at the overlap of the peaks of the green and blue standing waves.

2. The microcavity-enhanced quantum dot color-shifting structure according to claim 1, characterized in that, The microcavity-enhanced quantum dot color conversion structure includes a first isolation layer, which is stacked and disposed between the quantum dot conversion layer and the blue emitting layer along the cavity length extension direction of the microcavity structure; and / or The microcavity-enhanced quantum dot color conversion structure includes a second isolation layer, which is stacked and disposed between the quantum dot conversion layer and the second reflection layer along the cavity length extension direction of the microcavity structure.

3. The microcavity-enhanced quantum dot color-shifting structure according to claim 1, characterized in that, Both the first reflective layer and the second reflective layer are DBR reflective layers.

4. The microcavity-enhanced quantum dot color-shifting structure according to claim 1, characterized in that, The blue emitting layer includes an n-electrode, an n-GaN, a blue light multi-quantum well layer, a p-GaN, and a p-electrode stacked sequentially, wherein the blue light multi-quantum well emits the blue light; the n-electrode is stacked on the first reflective layer, and the p-electrode is stacked on the quantum dot conversion layer.

5. The microcavity-enhanced quantum dot color-shifting structure according to claim 1, characterized in that, The color-transfer structure of the microcavity enhanced quantum dot includes a black glue filling layer, which covers the periphery of the color-transfer structure of the microcavity enhanced quantum dot.

6. An application of a microcavity-enhanced quantum dot color-shifting structure, characterized in that, The color-conversion structure of the microcavity enhanced quantum dot described in claims 1 to 5 is applied to Mini-LED / Micro-LED full-color display devices.

7. A method for preparing a microcavity-enhanced quantum dot color-changing structure, characterized in that, Includes the following steps: A first reflective layer is deposited, a substrate is prepared, and the first reflective layer is stacked on one side of the substrate; A blue light-emitting layer is deposited, the blue light-emitting layer is prepared and processed and stacked on the side of the first reflective layer away from the substrate, and the blue light-emitting layer emits blue light; A quantum dot conversion layer is deposited and stacked on one side of the blue light-emitting layer, which can convert the blue light into red or green light. A second reflective layer is deposited, and the second reflective layer is stacked on the side of the quantum conversion layer opposite to the blue light-emitting layer. A microcavity structure is formed between the first reflective layer and the second reflective layer. The quantum dot conversion layer includes red quantum dots, which are used to convert blue light into red light. The cavity length of the microcavity structure is simultaneously equal to an integer multiple of both the half-wavelength of the blue light and the half-wavelength of the red light. Alternatively, the quantum dot conversion layer includes green quantum dots, which are used to convert the blue light into green light. The cavity length of the microcavity structure is designed to be simultaneously equal to an integer multiple of both the half-wavelength of the blue light and the half-wavelength of the green light. The first reflective layer and the second reflective layer are configured to form stable resonance conditions for blue and green light or stable resonance conditions for blue and red light within the microcavity structure. In this configuration, light is reflected within the microcavity structure to form blue and red standing waves. Along the length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave, and the quantum dot conversion layer is located at the overlap of the peaks of the red and blue standing waves. Alternatively, light is reflected within the microcavity structure to form blue and green standing waves. Along the length of the microcavity structure, the blue emitting layer is located at the peak of the blue standing wave, and the quantum dot conversion layer is located at the overlap of the peaks of the green and blue standing waves.

8. The method for preparing the color-changing structure of microcavity-enhanced quantum dots according to claim 7, characterized in that, Before the step of depositing the quantum dot conversion layer, a first isolation layer is processed and stacked on the light-emitting surface of the blue light-emitting layer, and microcavity structures with different cavity lengths are obtained by spin-coating the first isolation layer of different thicknesses; and / or, before the step of depositing the second reflective layer, a second isolation layer is processed and stacked on the light-emitting surface of the quantum dot conversion layer, and microcavity structures with different cavity lengths are obtained by spin-coating the second isolation layer of different thicknesses.

9. The method for preparing the color-changing structure of microcavity-enhanced quantum dots according to claim 7, characterized in that, In the step of depositing the first reflective layer, a multilayer high and low refractive index dielectric material is deposited on one side of the substrate using electron beam enhancement to form a DBR reflective layer as the first reflective layer; and / or, in the step of depositing the second reflective layer, a multilayer high and low refractive index dielectric material is deposited on the side of the quantum dot conversion layer opposite to the blue light-emitting layer using electron beam enhancement to form a DBR reflective layer as the second reflective layer.

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