Silicon-based oled microdisplay

Abstract

The application relates to the technical field of silicon-based OLED micro-displays, and discloses a silicon-based OLED micro-display which comprises a silicon-based backboard, an organic light-emitting layer and an encapsulating layer; the organic light-emitting layer is internally provided with a double-layer blue light-emitting layer and a buffer layer; the blue light-emitting material in the double-layer blue light-emitting layer is doped with a rare earth element; a thin film encapsulating material layer in the encapsulating layer is formed by alternately depositing inorganic materials and organic materials; the silicon-based backboard is used for bearing and integrating a driving circuit; the organic light-emitting layer is used for realizing image display under current driving; and the encapsulating layer is used for protecting the organic light-emitting layer and blocking water and oxygen. In the application, the double-layer blue light-emitting layer can make the blue light-emitting layers have reasonable energy transmission and charge distribution mechanisms, thereby improving the problem that the molecular structure of the blue light-emitting material in the traditional OLED material is relatively unstable and the service life is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon-based OLED micro-displays, in particular to a silicon-based OLED micro-display. BACKGROUND

[0002] OLED micro-displays are an advanced display technology. OLED stands for Organic Light-Emitting Diode, and micro-display refers to a display with a relatively small size. Structurally, it achieves light emission through an organic material coating on a base material. This display has the characteristic of self-emission, and does not require a backlight source. Compared with traditional liquid crystal displays, it can be made thinner. Its pixels can be independently controlled to emit light, which enables it to present deep black and extremely high contrast, and the colors are more vivid and lively, with a very wide viewing angle, almost clear from all angles. In application fields, OLED micro-displays play a key role in virtual reality (VR) and augmented reality (AR) devices. Because of its high resolution and small size, it can provide a clear visual experience in a compact head-mounted device. At the same time, it is also widely used in some high-end electronic viewfinders, micro projectors and other devices, which can display high-quality images in a small space, and has promoted the progress of these devices in performance and portability.

[0003] The molecular structure of blue light-emitting materials in traditional OLED materials is relatively unstable. During current passing and long-term use, the chemical bonds inside the molecules are prone to breakage or rearrangement, leading to a decrease in the light-emitting performance of the material, and thus a decrease in the service life. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a silicon-based OLED micro-display, which solves the problem of the relatively unstable molecular structure of blue light-emitting materials in traditional OLED materials, which leads to a decrease in the light-emitting performance of the material and thus a decrease in the service life during current passing and long-term use.

[0005] To achieve the above purpose, the present application is implemented by the following technical scheme: a silicon-based OLED micro-display, comprising a silicon-based backplane, an organic light-emitting layer and an encapsulation layer, the organic light-emitting layer is provided with a double-layer blue light-emitting layer and a buffer layer, the blue light-emitting material in the double-layer blue light-emitting layer is doped with a rare earth element, the thin film encapsulation material layer in the encapsulation layer is formed by alternately depositing inorganic materials and organic materials, the silicon-based backplane is used to carry and integrate a driving circuit, the organic light-emitting layer is used to realize image display under current driving, and the encapsulation layer is used to protect the organic light-emitting layer and block water and oxygen.

[0006] Preferably, the silicon-based backplane comprises a single-crystal silicon substrate for providing a physical support platform for circuits and devices in the silicon-based OLED micro-display, CMOS driving circuits for precisely controlling the light-emitting state of each pixel in the silicon-based OLED micro-display, a metal interconnection layer for connecting different circuit elements and regions on the silicon-based backplane of the silicon-based OLED micro-display, and a passivation layer for protecting the circuit elements on the silicon-based backplane.

[0007] Preferably, the organic light-emitting layer further comprises an anode for injecting holes, a hole transport layer for transporting the holes injected from the anode to the light-emitting layer, an electron transport layer for transporting electrons from the cathode to the light-emitting layer, and a cathode for injecting electrons.

[0008] Preferably, the encapsulation layer further comprises a sealing adhesive layer for tightly adhering the thin-film encapsulation material layer to the glass cover plate, and a glass cover plate for providing physical protection for the silicon-based OLED micro-display.

[0009] Preferably, the blue light-emitting material is 9,10-bis(2-naphthyl)anthracene, the rare earth element is terbium triflate, the weight ratio of 9,10-bis(2-naphthyl)anthracene to terbium triflate is 95-99:0.1-5, and the rare earth element is doped by a solution method.

[0010] Preferably, the buffer layer is located between the hole transport layer and the blue light-emitting material, and the buffer layer material is tris(4-carbazoyl-9-ylphenyl)amine (TCTA) with a thickness controlled at 5-15 nanometers.

[0011] Preferably, the inorganic material in the thin-film encapsulation material layer is silicon nitride, and the organic material is parylene, and the weight ratio of silicon nitride to parylene is 40-60:45-65.

[0012] Preferably, the alternating deposition method comprises first depositing a layer of 50-100 nanometer-thick silicon nitride by PECVD, then solution spin-coating a layer of 100-200 nanometer-thick parylene, and repeating the process 3-5 times.

[0013] The present application provides a silicon-based OLED micro-display, which has the following advantages:

[0014] 1. In this invention, the double-layer blue light-emitting layer enables a reasonable energy transfer and charge distribution mechanism between each blue light-emitting layer. When the OLED device is working, it can disperse the total current flowing through the blue light-emitting region, reduce the current density borne by each blue light-emitting layer, reduce the material aging problem caused by high current density, and extend the overall lifespan of the blue light-emitting material. This improves the problem that the molecular structure of the blue light-emitting material in traditional OLED materials is relatively unstable, and the chemical bonds inside the molecules are easily broken or rearranged during current flow and long-term use, which leads to a decrease in the luminescent performance of the material and thus a reduction in lifespan.

[0015] 2. In this invention, rare earth elements are doped into the main blue luminescent organic material. The rare earth elements achieve energy transfer and exciton stabilization during the current flow and luminescence process through their special electronic structure, so as to reduce energy loss, delay material aging, and thus improve luminescence efficiency and stability, and enhance the service life of the blue luminescent material in OLED devices.

[0016] 3. In this invention, a buffer layer is provided between the blue light-emitting layer and the adjacent hole transport layer. The buffer layer material can regulate the rate and quantity of holes and electrons injected into the blue light-emitting layer, so that the holes and electrons injected into the blue light-emitting layer reach a more matched state, reduce the damage to the blue light-emitting material caused by charge accumulation, and extend the life of the blue light-emitting material in the OLED device.

[0017] 4. In this invention, silicon nitride and parylene are used in the thin film encapsulation material layer through alternating deposition. Silicon nitride provides water and oxygen barrier function, while parylene acts as a stress buffer to prevent cracks from appearing in the inorganic layer. Through this multi-layer structure synergistic effect, external water and oxygen are effectively blocked from entering the interior of the OLED device, protecting the blue light-emitting material and extending the service life of the OLED device. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of the present invention. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see the appendix Figure 1The embodiment of the present application provides a silicon-based OLED micro display, which is characterized by comprising a silicon-based backboard, an organic light-emitting layer and an encapsulation layer, the organic light-emitting layer is internally provided with a double-layer blue light-emitting layer and a buffer layer, the blue light-emitting material in the double-layer blue light-emitting layer is doped with a rare earth element, the thin film encapsulation material layer in the encapsulation layer is formed by alternately depositing inorganic materials and organic materials, the silicon-based backboard is used for bearing and integrating a driving circuit, the organic light-emitting layer is used for realizing image display under current driving, and the encapsulation layer is used for protecting the organic light-emitting layer and blocking water and oxygen.

[0021] Specifically, the silicon-based backboard can provide stable physical support for the silicon-based OLED micro display, integrate a driving circuit to accurately control pixel light emission, guarantee signal transmission and improve device performance and stability, the organic light-emitting layer can make electrons and holes combine to occur energy transition under current driving, thereby generating visible light to realize the light-emitting function of image display, the organic light-emitting layer is further provided with a red light-emitting layer, a green light-emitting layer and a white light-emitting layer, the encapsulation layer can effectively block harmful external factors such as water, oxygen and dust, protect the internal device structure, ensure the performance stability of the silicon-based OLED micro display and prolong the service life, the double-layer blue light-emitting layer can improve the blue light-emitting efficiency and enhance the blue light-emitting intensity, and is helpful to adjusting the spectral characteristics of blue light emission, improving the color purity and color stability of blue light, and thereby improving the display quality of the silicon-based OLED micro display, the buffer layer can effectively relieve the stress caused by the difference in thermal expansion coefficient of different materials or external mechanical stress, and can improve the interface characteristics, improve the charge injection and transmission efficiency, and thereby improve the stability and performance of the device, the blue light-emitting material doped with a rare earth element can effectively improve the light-emitting efficiency, improve the color purity, enhance the light-emitting stability and adjust the light-emitting spectrum, and improve the quality of blue display of the silicon-based OLED micro display, and the thin film encapsulation material layer formed by alternately depositing inorganic materials and organic materials can effectively combine the high barrier property of inorganic materials and the flexibility and buffering property of organic materials, significantly improve the barrier effect of harmful factors such as water vapor and oxygen, enhance the encapsulation stability, and prolong the service life of the device.

[0022] The silicon-based backboard comprises a single crystal silicon substrate, a CMOS driving circuit, a metal interconnection layer and a passivation layer, the single crystal silicon substrate is used for providing a physical support platform for the circuits and devices in the silicon-based OLED micro display, the CMOS driving circuit is used for accurately controlling the light-emitting state of each pixel in the silicon-based OLED micro display, the metal interconnection layer is used for connecting different circuit elements and regions on the silicon-based backboard of the silicon-based OLED micro display, and the passivation layer is used for protecting the circuit elements on the silicon-based backboard.

[0023] Specifically, the single crystal silicon substrate can ensure the integrity of the device structure, serve as a good thermal conduction medium, and facilitate high-precision micro-nano processing, thereby improving the display performance and manufacturing precision. The CMOS driving circuit can accurately control the light emission and intensity of each pixel in the silicon-based OLED micro display, enabling fast and efficient signal conversion and transmission, thereby ensuring high-quality and high-resolution image display. The metal interconnection layer can realize electrical connection between various elements (such as pixel electrodes and driving circuits) in the silicon-based OLED micro display, effectively transmit electrical signals, and ensure signal integrity and stability, thereby ensuring normal operation and performance of the display. The passivation layer can protect the active layer and metal interconnection in the silicon-based OLED micro display from water vapor, chemical substances, and mechanical scratches, while reducing surface charge accumulation and improving device stability and reliability.

[0024] The organic light-emitting layer further includes an anode, a hole transport layer, an electron transport layer, and a cathode. The anode is used to inject holes, the hole transport layer is used to transport holes injected from the anode to the light-emitting layer, the cathode is used to inject electrons, and the electron transport layer is used to transport electrons from the cathode to the light-emitting layer.

[0025] Specifically, the anode can effectively receive holes and inject them into the organic light-emitting layer, while also serving as a current collector and connecting to external circuits. The hole transport layer can promote the effective transport of holes injected from the anode to the organic light-emitting layer, adjust the injection efficiency of holes, and balance the charge distribution in the light-emitting layer, thereby improving the light-emitting efficiency and performance of the device. The electron transport layer can enable electrons to be smoothly transported from the cathode to the organic light-emitting layer and effectively block holes, helping to achieve more efficient recombination of electrons and holes in the light-emitting layer, thereby improving the light-emitting efficiency and brightness uniformity of the silicon-based OLED micro display. The cathode can effectively inject electrons, which recombine with holes injected from the anode and transported through the hole transport layer in the organic light-emitting layer, thereby initiating the light-emitting process and serving as a connection to external circuits and forming a complete circuit loop.

[0026] The encapsulation layer further includes a sealing adhesive layer and a glass cover plate. The glass cover plate is used to provide physical protection for the silicon-based OLED micro display, and the sealing adhesive layer is used to tightly bond the thin film encapsulation material layer and the glass cover plate.

[0027] Specifically, the sealing glue layer can form a sealing structure at the edge of the silicon-based OLED micro display, prevent harmful substances such as water vapor, oxygen and dust from the outside from entering the inside of the display, assist the packaging layer to enhance the overall sealing performance, and protect the stability and service life of the display. The glass cover can provide physical protection for the silicon-based OLED micro display, prevent it from being mechanically damaged or scratched by the outside world, block dust, water vapor and other pollutants, and to some extent reduce external light interference and improve display effect.

[0028] The blue light-emitting material is 9,10-di(2-naphthyl) anthracene, the rare earth element is terbium triflate, and the weight ratio of 9,10-di(2-naphthyl) anthracene to terbium triflate is 95-99:0.1-5. The rare earth element is doped by a solution method.

[0029] Specifically, the blue light-emitting material 9,10-di(2-naphthyl) anthracene can emit blue light with a wavelength of 435-445 nm, has high fluorescence quantum yield, and can effectively realize blue light emission, providing a high-quality blue light source for the silicon-based OLED micro display. The rare earth element is terbium triflate, which can fine-tune the light-emitting performance by energy transfer or changing the electronic structure of the host material to improve the light-emitting efficiency.

[0030] The buffer layer is located between the hole transport layer and the blue light-emitting material, and the buffer layer material is tris(4-carbazol-9-ylphenyl) amine (TCTA) with a thickness of 5-15 nanometers.

[0031] Specifically, the buffer layer located between the hole transport layer and the blue light-emitting material can adjust the injection rate and amount of holes, reduce energy loss and charge accumulation at the interface, optimize the charge injection balance between holes and light-emitting materials, and thus improve the light-emitting efficiency and stability of the silicon-based OLED micro display. The buffer layer material is tris(4-carbazol-9-ylphenyl) amine (TCTA), which can effectively improve the injection efficiency of holes from the hole transport layer to the blue light-emitting material, balance charge transport, reduce interface traps, and thus improve the light-emitting performance and stability of the silicon-based OLED micro display. The thickness is controlled to be 5-15 nanometers, which can ensure effective regulation of charge injection and transport while avoiding increased resistance and prolonged response time due to excessive thickness, or failing to fully play the buffering role due to excessive thinness, thereby optimizing the performance of the silicon-based OLED micro display.

[0032] The inorganic material in the thin film encapsulation material layer is silicon nitride, and the organic material is parylene. The weight ratio of silicon nitride to parylene is 40-60:45-65.

[0033] Specifically, by using silicon nitride as the inorganic material in the thin film encapsulation material layer, the excellent gas barrier property (good barrier effect for water vapor and oxygen) of the silicon nitride can effectively protect the internal device structure, improve the stability and service life of the silicon-based OLED micro display, by using polyparaxylylene as the organic material, good flexibility and buffering property can be provided to cover the small unevenness on the surface of the device, assist the inorganic material to enhance the barrier effect of the overall encapsulation, improve the mechanical stress resistance and moisture resistance of the silicon-based OLED micro display, by using the weight ratio of 40-60:45-65 of silicon nitride to polyparaxylylene, a good balance between the high barrier property of the inorganic material and the flexibility of the organic material in the thin film encapsulation material layer can be achieved, the encapsulation quality of the silicon-based OLED micro display can be effectively improved, and the comprehensive performance of resisting water vapor, oxygen penetration and mechanical damage can be enhanced.

[0034] The alternating deposition method is to first deposit a layer of 50-100 nm thick silicon nitride by PECVD, then spin-coat a layer of 100-200 nm thick polyparaxylylene, and repeat 3-5 times.

[0035] Specifically, by using this alternating deposition method, the excellent gas barrier property of silicon nitride and the good flexibility and flatness of polyparaxylylene can be fully combined to form a multi-layer composite encapsulation structure, effectively block the invasion of harmful substances such as water vapor and oxygen, and greatly enhance the stability, reliability and damage resistance of the silicon-based OLED micro display encapsulation.

[0036] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A silicon-based OLED microdisplay, comprising a silicon-based backplane, an organic light-emitting layer, and an encapsulation layer, characterized in that: The organic light-emitting layer comprises a double-layer blue light-emitting layer and a buffer layer. The blue light-emitting material in the double-layer blue light-emitting layer is doped with rare earth elements. The thin-film encapsulation material layer in the encapsulation layer is formed by alternating deposition of inorganic and organic materials. The silicon-based backplane is used to support and integrate the driving circuit. The organic light-emitting layer is used to realize image display under current drive. The encapsulation layer is used to protect the organic light-emitting layer and block water and oxygen. The blue light-emitting material is 9,10-bis(2-naphthyl)anthracene, and the material containing the rare earth elements is terbium trifluoromethanesulfonate. The weight ratio of 9,10-bis(2-naphthyl)anthracene to terbium trifluoromethanesulfonate is 95-99. 0.1-5, the materials containing the rare earth elements are doped by solution method.

2. The silicon-based OLED microdisplay according to claim 1, characterized in that: The silicon-based backplane includes a monocrystalline silicon substrate, a CMOS driving circuit, a metal interconnect layer, and a passivation layer. The monocrystalline silicon substrate is used to provide a physical support platform for the circuits and devices in the silicon-based OLED microdisplay. The CMOS driving circuit is used to precisely control the light emission state of each pixel in the silicon-based OLED microdisplay. The metal interconnect layer is used to connect different circuit elements and areas on the silicon-based backplane of the silicon-based OLED microdisplay. The passivation layer is used to protect the circuit elements on the silicon-based backplane.

3. A silicon-based OLED microdisplay according to claim 1, characterized in that: The organic light-emitting layer further includes an anode, a hole transport layer, an electron transport layer, and a cathode. The anode is used to inject holes, the hole transport layer is used to transport holes injected from the anode to the light-emitting layer, the cathode is used to inject electrons, and the electron transport layer is used to transport electrons from the cathode to the light-emitting layer.

4. A silicon-based OLED microdisplay according to claim 1, characterized in that: The encapsulation layer also includes a sealant layer and a glass cover plate. The glass cover plate is used to provide physical protection for the silicon-based OLED microdisplay, and the sealant layer is used to tightly bond the thin-film encapsulation material layer to the glass cover plate.

5. A silicon-based OLED microdisplay according to claim 3, characterized in that: The buffer layer is located between the hole transport layer and the blue luminescent material. The buffer layer material is tris(4-carbazole-9-ylphenyl)amine (TCTA), and the thickness is controlled at 5-15 nanometers.

6. A silicon-based OLED microdisplay according to claim 1, characterized in that: The inorganic material in the thin-film encapsulation material layer is silicon nitride, and the organic material is parylene.

7. A silicon-based OLED microdisplay according to claim 1, characterized in that: The alternating deposition method involves first depositing a 50-100 nm thick layer of silicon nitride via PECVD, followed by spin-coating a 100-200 nm thick layer of parylene, repeating this process 3-5 times.

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