White light device with high communication rate and preparation method thereof

Abstract

The invention discloses a white light device with a high communication rate and a preparation method thereof, and the white light device comprises a light-emitting diode chip which is used for emitting exciting light; the color conversion layer is located on the light-emitting diode chip and used for forming white light through excitation of exciting light, the color conversion layer comprises at least two kinds of photoluminescence fluorescent materials, and fluorescence resonance energy transfer occurs between the different kinds of photoluminescence fluorescent materials; and an organic polymer encapsulation layer on the color conversion layer. According to the white light wireless communication device, the fluorescence lifetime of a fluorescent substance serving as a donor is reduced through fluorescence resonance energy transfer of at least two fluorescent materials so as to improve the modulation bandwidth, and it is verified that the mixed fluorescent substance in the color conversion layer has better communication performance than a single fluorescent substance.

Description

Technical Field

[0001] The present invention relates to the technical field of optical wireless communication, and in particular to a white light device with a high communication rate and a preparation method thereof. Background Art

[0002] With the continuous development of information technology, people's demand for wireless communication is growing. Traditional radio frequency wireless communication faces problems such as limited spectrum resources and limited transmission rate. In order to solve these problems, optical wireless communication technology (Optical Wireless Communication, OWC) has gradually emerged as a new type of wireless communication technology. Optical wireless communication uses visible light or infrared light to transmit information in free space. Compared with traditional radio frequency communication technology, optical wireless communication technology has more abundant spectrum resources, no need for spectrum license, higher bandwidth and transmission rate, good security, strong anti-interference ability and other advantages. In order to achieve a higher transmission rate, the transmitter in the optical wireless communication system must first meet the high-speed transmission requirements.

[0003] As the transmitting end light source of the optical wireless communication system, the white light emitting diode (WLED) has the advantages of stable light source, long life and low power consumption, and has become the first choice for the transmitting end light source of the optical wireless communication system. There are two main ways to make traditional white light emitting diodes. One is to use phosphors in combination with a single light emitting diode to form white light, and the other is to use a mixture of blue, green and red three-primary color light emitting diodes to produce white light. However, the phosphors used in the current white light emitting diodes are mainly aluminates, silicates and nitrogen (oxy) compounds. These phosphors have a long fluorescence life ranging from tens of microseconds to hundreds of microseconds, which leads to a very low modulation bandwidth of the phosphors, and the corresponding maximum communication rate that can be achieved in optical wireless communication is limited to less than ten megabits. On the other hand, although the white light emitting diodes using a mixed package of blue, green and red three-primary color light emitting diodes can improve their communication capabilities in optical wireless communication by reducing the size of the light emitting diode chip, such a solution faces problems such as high production process requirements, high production costs, poor heat dissipation and complex control circuits. These problems limit the application of white light emitting diodes in the field of optical wireless communication.

[0004] In order to overcome the above problems, in recent years, quantum dots, as a new type of light conversion material, have gradually been applied to white light emitting diode devices due to their advantages such as adjustable luminescence spectrum, narrow-band emission spectrum, good color rendering, high photoluminescence efficiency, good stability and short fluorescence lifetime. The quantum dot color conversion layer can convert the excitation light emitted by the light emitting diode chip into light of a longer wavelength band, and mix it with the excitation light to form white light with high color rendering and adjustable color temperature. Compared with traditional phosphor conversion technology, quantum dot color conversion technology has the advantages of higher conversion efficiency, wider spectral bandwidth, better color purity, higher modulation bandwidth, etc. White light emitting diodes using quantum dots as color conversion layers are more suitable for use in the transmitting end of optical wireless communication systems.

[0005] However, existing white light emitting diode devices still have some problems. The fluorescence lifetime of existing perovskite quantum dots, II-VI semiconductor quantum dots, IV-VI semiconductor quantum dots and organic dyes ranges from 3 nanoseconds to 20 nanoseconds, and the modulation bandwidth is from 10 MHz to 50 MHz. The modulation bandwidth of light-emitting diodes can be increased to more than 100 MHz by reducing the chip size, so the long fluorescence lifetime of the fluorescent material used in the color conversion layer of white light emitting diode devices still restricts the communication performance of white light emitting diode devices in optical wireless communication. Therefore, the development of a white light emitting diode device with high conversion efficiency, high color rendering, adjustable color temperature, high stability and high communication performance is of great significance to promote the development of optical wireless communication technology. Summary of the invention

[0006] In response to the existing technical problems, the present invention provides a white light device with a high communication rate. The white light wireless communication device reduces the fluorescence lifetime of the fluorescent substance as a donor to improve the modulation bandwidth through fluorescence resonance energy transfer between at least two photoluminescent fluorescent materials, and verifies that the mixed fluorescent substance in the color conversion layer has better communication performance than a single fluorescent substance.

[0007] The present invention provides a white light device with a high communication rate, comprising: A light emitting diode chip, used for emitting excitation light; A color conversion layer, located on the light-emitting diode chip, is used to generate white light through the excitation of the excitation light, wherein the color conversion layer includes at least two photoluminescent fluorescent materials, and fluorescence resonance energy transfer occurs between different photoluminescent fluorescent materials; The organic polymer encapsulation layer is located on the color conversion layer.

[0008] The present invention utilizes fluorescence resonance energy transfer between different types of photoluminescent fluorescent materials, and can efficiently transfer the energy of the fluorescent material as a donor to the fluorescent object as an acceptor in a non-radiative form, so that photons with longer wavelengths are emitted, thereby attenuating the fluorescence lifetime of the fluorescent material as the donor and thereby increasing the modulation bandwidth and communication rate of the fluorescent material's luminescence, thereby achieving high-speed white light wireless communication.

[0009] At the same time, the light emitted by the fluorescent material as the acceptor can complement the color of the light emitted by the fluorescent material as the donor, effectively utilizing the energy of the excitation light to obtain the required white light, that is, the present invention forms white light by mixing the long-wavelength light emitted by the photoluminescent material and the excitation light. By adjusting the ratio and concentration of the acceptor and the donor, the spectrum and color temperature of the white light can be adjusted.

[0010] Preferably, the photoluminescent fluorescent material is II-VI semiconductor quantum dots, IV-VI semiconductor quantum dots, organic light-emitting quantum dots, organic light-emitting dye molecules, carbon quantum dots or silicon quantum dots.

[0011] The above-mentioned photoluminescence efficiency quantum yield provided by the present invention is high, the fluorescence lifetime is short, and the modulation bandwidth is high. The color conversion layer formed by any combination thereof can further shorten the fluorescence lifetime and increase the modulation bandwidth. Its luminescence spectrum is in the 350-800 nanometer band and can receive the excitation light emitted by the light-emitting diode chip.

[0012] Preferably, the distance between any photoluminescent materials in the color conversion layer is 2 nanometers to 10 nanometers.

[0013] Preferably, the color conversion layer comprises a donor material and an acceptor material, the donor material and the acceptor material are different and both are from photoluminescent fluorescent materials, and the molar concentration ratio of the acceptor material to the donor material is 0.5-1.5.

[0014] The present invention utilizes the light of the acceptor material to supplement the color of the light of the donor material, and by controlling the molar concentration ratio and concentration, the spectrum and color temperature of white light can be adjusted to form white light with a high communication rate.

[0015] Further preferably, the donor material is perovskite quantum dots. Since the fluorescence lifetime of perovskite quantum dots is short, when used as donor materials, the fluorescence lifetime is further shortened, thereby significantly improving the modulation bandwidth and communication rate.

[0016] Preferably, the light emitting diode chip is a semiconductor with a light wave band of 380 nanometers to 480 nanometers, and is used to emit blue or purple excitation light.

[0017] Preferably, the material of the light emitting diode chip is gallium nitride (GaN), indium gallium nitride (InGaN), aluminum nitride (AlN), zinc sulfide (ZnS) or zinc selenide (ZnSe).

[0018] Preferably, the light transmittance of the organic polymer encapsulation layer is greater than 80%. It is used to encapsulate the light-emitting diode chip and the color conversion layer to improve the stability and service life of the device.

[0019] Preferably, the color conversion layer has a thickness of 50 nanometers to 200 micrometers, and the organic polymer encapsulation layer has a thickness of 100 micrometers to 2 millimeters.

[0020] On the other hand, the present invention also provides a method for preparing the white light device with high communication rate, comprising: (1) ultrasonically cleaning the surface of the light-emitting diode chip, and at the same time mixing and shaking at least two photoluminescent material solutions to obtain a mixed solution; (2) spin coating the mixed solution on the cleaned light-emitting diode chip to form a color conversion layer; (3) A polymer encapsulation layer is formed on the color conversion layer to obtain a white light device with a high communication rate.

[0021] In view of the defects of poor color rendering, low modulation bandwidth, and low communication rate of white light emitting diodes used as transmitters in current optical wireless communication systems, the present invention provides a white light emitting device based on fluorescence resonance energy transfer to improve the rate of white light wireless communication. The white light can achieve high luminous efficiency, adjustable color temperature, high color rendering index, and high modulation bandwidth, and the device can be used to achieve high communication rate in optical wireless communication systems.

[0022] The white light wireless communication device provided by the present invention contains perovskite quantum dots, II-VI semiconductor quantum dots, IV-VI semiconductor quantum dots, organic light-emitting quantum dots, carbon quantum dots, silicon quantum dots, organic light-emitting dye molecules, carbon quantum dots, silicon quantum dots, etc. with photoluminescent properties, which can absorb the excitation light emitted by the purple light-emitting diode chip or the blue light-emitting diode chip, and can match the different characteristic bands of the photodiode, APD detector, and PIN diode as the optical signal receiver and achieve higher responsiveness.

[0023] The fluorescent substance as the energy transfer donor in the color conversion layer of the white light wireless communication device provided by the present invention can regulate the fluorescence lifetime of the donor fluorescent substance by mixing with the fluorescent substance as the acceptor at different molar concentration ratios and transferring fluorescence energy. By selecting a suitable molar concentration ratio to mix the donor fluorescent substance and the acceptor fluorescent substance, and taking a suitable molar amount of the mixed solution to spin-coat on a blue light emitting diode or a purple light diode to form a color conversion layer, part of the excitation light emitted by the light emitting diode chip can be converted into a suitable proportion of longer wavelength light to mix with the remaining excitation light to form white light with adjustable color temperature and high color rendering, and the device can be used to achieve high communication rate in an optical wireless communication system.

[0024] The white light wireless communication device provided by the present invention uses fluorescent materials with high photoluminescence efficiency, good stability and short fluorescence lifetime, so as to achieve white light with high conversion efficiency, high color rendering index (>80) and adjustable color temperature between 2700K and 8000K. This advantage enables the present invention to significantly improve the luminous efficiency and signal quality, and can more effectively send high-speed signals as a transmitting end in an optical wireless communication system.

[0025] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a white light emitting device that attenuates the fluorescence lifetime of a fluorescent substance serving as a donor by regulating fluorescence resonance energy transfer between different fluorescent substances, further utilizing the mixed fluorescent substance as a color conversion layer of a blue light emitting diode or a purple light emitting diode to convert part of the excitation light into light of a longer wavelength to be mixed to form white light, thereby realizing high-speed communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a white light emitting device for improving the white light wireless communication rate through fluorescence resonance energy transfer in the present invention, and the accompanying drawings are marked as follows: 1. organic polymer encapsulation layer, 2. color conversion layer, 3. light emitting diode chip; Figure 2 The absorption and emission spectra of the green light CsPbBr3 quantum dots and the red light CdSe / ZnS quantum dots prepared in Example 1 of the present invention; Figure 3 The emission spectra of mixed solutions of green light CsPbBr3 quantum dots and red light CdSe / ZnS quantum dots in different proportions prepared in Example 1 of the present invention under 405 nanometer excitation; Figure 4 This is a quantum dot morphology image of the color conversion layer prepared in Example 1 of the present invention; Figure 5 This is a light emission spectrum diagram of the white light wireless communication device prepared in Example 1 of the present invention; Figure 6This is a color coordinate diagram of the white light wireless communication device obtained in Example 1 of the present invention; Figure 7 The fluorescence lifetime curve of CsPbCl3 quantum dots in mixed solutions of blue light CsPbCl3 quantum dots and yellow light CdSe / ZnS quantum dots in different proportions prepared in Example 3 of the present invention; Figure 8 The -3dB modulation bandwidth diagram of CsPbCl3 quantum dots in mixed solutions of blue light CsPbCl3 quantum dots and yellow light CdSe / ZnS quantum dots in different proportions prepared in Example 3 of the present invention; Fig. 9 This is a communication rate curve based on OOK coding of the white light wireless communication device prepared in Example 4 of the present invention. DETAILED DESCRIPTION

[0027] The existing research on white light emitting diode devices still has the following problems to be solved: the fluorescence lifetime of the fluorescent material used in the color conversion layer of the white light emitting diode device is still relatively high, which limits the communication performance of the white light emitting diode device in optical wireless communication; Since the modulation bandwidth of the light-emitting diode is closely related to its chip size. The smaller the chip size of the light-emitting diode, the shorter the diffusion distance of the carriers in the chip, thereby shortening the carrier life, making the light-emitting diode faster in response and having a higher modulation bandwidth. On the other hand, the smaller the chip size of the light-emitting diode, the smaller its capacitance, thereby reducing the influence of capacitance on the response speed of the light-emitting diode. The fluorescence lifetime of existing perovskite quantum dots, II-VI semiconductor quantum dots, IV-VI semiconductor quantum dots and organic dyes ranges from 3 nanoseconds to 20 nanoseconds, and the modulation bandwidth is from 10 megahertz to 50 megahertz, while micron-sized light-emitting diodes with chip sizes of tens of microns can achieve a modulation bandwidth of more than one hundred megahertz. The color conversion layer restricts the communication performance of white light-emitting diode devices in optical wireless communications, so there is an urgent need to develop new white light-emitting diode devices to enhance their communication capabilities in optical wireless communications.

[0028] Fluorescence resonance energy transfer is a non-radiative energy transfer process that occurs between a donor molecule in an excited state and an acceptor molecule in a ground state. The donor molecule usually emits at a shorter wavelength and overlaps with the absorption spectrum of the acceptor. This energy transfer process does not involve the generation of photons and is the result of long-range dipole-dipole interactions between the donor and acceptor molecules, which causes the molecules in the excited state to release energy and transition back to the ground state at a faster rate. Using different fluorescent materials as donors and acceptors for fluorescence resonance energy transfer can regulate the attenuation of the fluorescence lifetime of the fluorescent material used as the donor, thereby improving its communication capability in optical wireless communications.

[0029] The specific embodiment of the present invention can efficiently transfer the energy of the fluorescent substance serving as a donor to the fluorescent substance serving as an acceptor in a non-radiative form through fluorescence resonance energy transfer between different fluorescent substances, so as to emit photons with a longer wavelength, thereby achieving the controlled attenuation of the luminescence lifetime of the fluorescent substance serving as the donor, thereby improving the modulation bandwidth and communication rate of the luminescence of the fluorescent substance.

[0030] A specific embodiment of the present invention proposes a new type of white light emitting device using a fluorescence resonance energy transfer color conversion layer, which overcomes the shortcomings of existing white light emitting devices in terms of modulation bandwidth and low communication rate, and achieves white light with high light conversion efficiency, high color purity, high color rendering, adjustable color temperature, and high modulation bandwidth. The device effectively improves the communication capability of white light wireless communication technology.

[0031] A white light emitting device provided by a specific embodiment of the present invention is Figure 1 As shown, it includes a light-emitting diode chip 1, a color conversion layer 2 and an organic polymer encapsulation layer 3; the light-emitting diode chip 1 is a purple light-emitting diode or a blue light-emitting diode, and the light-emitting wavelength is between 380 nanometers and 480 nanometers; the color conversion layer 2 is located on the light-emitting diode chip 1, and there are at least two fluorescent substances in the color conversion layer 2, which can be photoexcited by a light source of 380 nanometers to 480 nanometers and have a light-emitting spectrum in the wavelength range of 350-800 nanometers, and perovskite quantum dots, II-VI semiconductor quantum dots, and IV-VI semiconductor quantum dots are selected. , organic light-emitting quantum dots, organic light-emitting dye molecules, carbon quantum dots, silicon quantum dots, etc., there is fluorescence resonance energy transfer between different types of fluorescent substances, located on the emission surface of the light-emitting diode chip 1, and is used to convert the excitation light emitted by the light-emitting diode chip into long-wavelength light and mix it with the excitation light to form white light; the thickness of the color conversion layer is between 50 nanometers and 500 nanometers, and the thickness of the organic polymer encapsulation layer 3 is between 100 microns and 2 millimeters; the organic polymer encapsulation layer 3 is located on the color conversion layer 2, and the light transmittance of the organic polymer encapsulation layer 3 is higher than 90%.

[0032] The color conversion layer provided in the specific embodiment of the present invention includes at least two different fluorescent substances. When the two fluorescent substances satisfy the emission spectrum of the fluorescent substance emitting short-wavelength photons and the absorption spectrum of the fluorescent substance emitting long-wavelength photons, and the distance between the two fluorescent substances is between 2 nanometers and 10 nanometers, fluorescence resonance energy transfer will occur between the two fluorescent substances, wherein the fluorescent substance emitting short-wavelength photons serves as the donor of fluorescence resonance energy transfer, and the fluorescent substance emitting long-wavelength photons serves as the acceptor of fluorescence resonance energy transfer. Fluorescence resonance energy transfer is a non-radiative process, in which no photons are generated, and the energy of the donor is directly transferred to the acceptor through the long-distance dipole-dipole interaction between the donor molecule and the acceptor molecule. This process is shorter than the time for the fluorescent substance to emit photons, so the fluorescence lifetime of the fluorescent substance as the donor can be attenuated. By regulating the ratio of the fluorescent substances as the donor and the acceptor, the efficiency of fluorescence resonance energy transfer between the donor and the acceptor can be regulated, thereby regulating the fluorescence lifetime of the donor and the photoluminescence spectrum of the donor and the acceptor. By selecting a suitable donor-acceptor ratio, the excitation light emitted by the light-emitting diode can be made to form white light after exciting the color conversion layer while attenuating the donor fluorescence lifetime, thereby achieving white light with high light conversion efficiency, high color purity, high color rendering, adjustable color temperature, and high modulation bandwidth.

[0033] The preparation method of the high communication rate white light device provided in the specific embodiment of the present invention has a simple and convenient preparation process, can be quickly prepared at room temperature, and the color conversion layer in the prepared white light emitting device has an absorption conversion rate of up to 90% for the excitation light emitted by the light emitting diode (wherein the fluorescent materials are CsPbBr3 quantum dots and Cdse / ZnS quantum dots, and the light emitting diode is a blue light GaN light emitting diode chip), which verifies that the prepared white light emitting device has a high luminous efficiency.

[0034] The optical wireless communication system combined with white light emitting devices that improve the white light wireless communication rate through fluorescence resonance energy transfer was tested for communication performance on a communication test platform, verifying that the white light emitting devices prepared by this method can achieve high-speed white light wireless communication, which is expected to break through the limitations of existing optical wireless communications and show excellent application potential.

[0035] Example 1: This example illustrates how to prepare a white light emitting device that improves the white light wireless communication rate through fluorescence resonance energy transfer based on a blue light emitting diode chip, green light CsPbBr3 quantum dots and red light CdSe / ZnS quantum dots, and completes the communication performance test: (1) Ultrasonic cleaning of blue light emitting diode chips using GaN as the light emitting material to ensure the cleanliness of the chip surface.

[0036] (2) Using the hot injection method, green CsPbBr3 quantum dot solutions and red CdSe / ZnS quantum dot solutions with uniform size distribution, high photoluminescence efficiency, and photoexcitation by a light source of 350 nm to 480 nm were prepared; the photoluminescence efficiency of the prepared quantum dots was tested using an integrating sphere and was found to be above 90%; the emission and absorption spectra of the prepared quantum dots were tested using a spectrometer and a spectrophotometer. Figure 2 shown.

[0037] (3) The two quantum dot solutions prepared above were mixed at a certain molar concentration ratio, and the mixed solution was fully shaken to make the two quantum dots evenly distributed in the mixed solution. The luminescence spectra of the mixed quantum dot solutions with single CsPbBr3 quantum dots and acceptor-donor ratios of 0.25, 0.5, 1.0 and 2.0 were excited at 405 nm. Figure 3 shown.

[0038] (4) Spin-coat the mixed quantum dot solution with the acceptor-donor ratio of 1.0 on the light-emitting diode chip to form a color conversion layer, so that the two quantum dots are evenly mixed and distributed in the color conversion layer, and observe the morphology of the quantum dots in the color conversion layer using a transmission electron microscope. Figure 4 shown.

[0039] (5) Polymethyl methacrylate was used to encapsulate the light-emitting diode chip and the color conversion layer, and the luminescence spectrum and color coordinates of the prepared device were tested using a spectrometer. Figure 5 and Figure 6 shown.

[0040] In this example, a white light emitting device is used to improve the white light wireless communication rate by fluorescence resonance energy transfer between green light CsPbBr3 quantum dots and red light CdSe / ZnS quantum dots. The photoluminescence performance test using an integrating sphere proves that the device prepared by the method has high luminous efficiency. The transmission electron microscope proves that different fluorescent substances in the color conversion layer are evenly distributed.

[0041] Example 2: This example illustrates how to prepare a white light emitting device that improves the white light wireless communication rate through fluorescence resonance energy transfer based on purple light emitting diode chips, blue light CsPbCl3 quantum dots, green light CdSe / CdS quantum dots and red light CdSe / ZnS quantum dots, and complete the communication performance test: (1) Ultrasonic cleaning of ultraviolet light-emitting diode chips using GaN as the light-emitting material to ensure the cleanliness of the chip surface.

[0042] (2) The blue light CsPbCl3 quantum dot solution, green light CdSe / CdS quantum dot solution and red light CdSe / ZnS quantum dot solution with uniform size distribution, high photoluminescence efficiency and photoexcitation by 350nm to 480nm light source were prepared by hot injection method. The photoluminescence efficiency of the prepared quantum dots was tested by integrating sphere and reached more than 90%.

[0043] (3) The three quantum dot solutions prepared above were mixed at a molar concentration ratio of 3:1.5:1, and the mixed solution was fully shaken to ensure that the three quantum dots were evenly distributed in the mixed solution.

[0044] (4) Spin-coating a mixed quantum dot solution mixed in a specific ratio onto a light-emitting diode chip to form a color conversion layer, so that the three quantum dots are evenly mixed and distributed in the color conversion layer.

[0045] (5) Use polycarbonate to encapsulate the light-emitting diode chip and the color conversion layer.

[0046] This example shows that the device proposed in the present invention can be prepared by exciting different fluorescent materials in the mixed blue, green and red light emission bands through a purple light emitting diode chip, thereby proving the universality of the present invention.

[0047] Example 3: This example illustrates how to prepare a white light emitting device that improves the white light wireless communication rate through fluorescence resonance energy transfer based on purple light emitting diode chips, blue light CsPbCl3 quantum dots and yellow light CdSe / ZnS quantum dots, and complete the communication performance test: (1) Ultrasonic cleaning of ultraviolet light-emitting diode chips using GaN as the light-emitting material to ensure the cleanliness of the chip surface.

[0048] (2) The blue light CsPbCl3 quantum dot solution and the yellow light CdSe / ZnS quantum dot solution with uniform size distribution and high photoluminescence efficiency, which can be photoexcited by 350nm to 480nm light source, were prepared by hot injection method. The photoluminescence efficiency of the prepared quantum dots was over 90% when tested by integrating sphere.

[0049] (3) The two quantum dot solutions prepared above were mixed at a donor-acceptor molar concentration of 0.1-2.0, and the mixed solution was fully shaken to make the two quantum dots evenly distributed in the mixed solution. The fluorescence lifetime of the donor CsPbCl3 quantum dots after single CsPbCl3 quantum dots and CsPbCl3 quantum dots and CdSe / ZnS quantum dots were mixed at a donor-acceptor molar concentration ratio of 0.1-2.0 was tested using a femtosecond laser, a spectrometer and a streak camera. Figure 7 As shown in Figure 2, with the increase of CdSe / ZnS quantum dot content, the fluorescence lifetime of the donor CsPbCl3 quantum dots decreases. The -3dB modulation bandwidth of single CsPbCl3 quantum dots and CsPbCl3 quantum dots mixed with CdSe / ZnS quantum dots at different molar concentration ratios were tested using a vector network analyzer and an APD detector. Figure 8 As shown in the figure, with the increase of CdSe / ZnS quantum dot content, the modulation bandwidth shows an upward trend.

[0050] (4) Spin-coating a mixed quantum dot solution mixed at a molar ratio of 0.9 between the acceptor and the donor on a light-emitting diode chip to form a color conversion layer, so that the two quantum dots are evenly mixed and distributed in the color conversion layer. (5) Polyethylene terephthalate is used for encapsulation on the light-emitting diode chip and the color conversion layer.

[0051] In this example, a white light emitting device is used to improve the rate of white light wireless communication through fluorescence resonance energy transfer between blue light CsPbCl3 quantum dots and yellow light CdSe / ZnS quantum dots. The optical properties of the mixed blue light CsPbCl3 quantum dots and yellow light CdSe / ZnS quantum dots are characterized, and the changing lifespan proves that fluorescence resonance energy transfer exists between different quantum dots, such as Figure 7 By testing the communication performance of mixed blue light CsPbCl3 quantum dots and yellow light CdSe / ZnS quantum dots, it is proved that fluorescence resonance energy transfer can enhance the communication capability of white light, as shown in Figure 2. Figure 8 shown.

[0052] Example 4: This example illustrates how to prepare a white light emitting device that improves the white light wireless communication rate through fluorescence resonance energy transfer based on a blue light emitting diode chip, green light CsPbBr3 quantum dots and red light LR306 organic fluorescent dye, and completes the communication performance test: (1) Ultrasonic cleaning of blue light emitting diode chips using GaN as the light emitting material to ensure the cleanliness of the chip surface.

[0053] (2) A green light CsPbBr3 quantum dot solution with uniform size distribution, high photoluminescence efficiency, and photoexcitation by a 350-nm to 480-nm light source was prepared using a hot injection method. The photoluminescence efficiency of the prepared quantum dots tested using an integrating sphere was over 90%.

[0054] (3) The quantum dot solution prepared above and the LR306 organic fluorescent dye solution were mixed at a donor-acceptor molar concentration ratio of 0.9, and the mixed solution was fully shaken to ensure that the two fluorescent substances were evenly distributed in the mixed solution.

[0055] (4) Spin-coating the mixed solution mixed in a specific ratio onto a light-emitting diode chip to form a color conversion layer, so that the two fluorescent substances are evenly mixed and distributed in the color conversion layer.

[0056] (5) Polysiloxane is used to encapsulate the light-emitting diode chip and the color conversion layer, and the communication capability of the prepared white light-emitting device is tested based on OOK coding using an arbitrary waveform generator, an APD detector and an oscilloscope. Fig. 9 shown.

[0057] This example uses fluorescence resonance energy transfer between green CsPbBr3 quantum dots and red LR306 organic fluorescent dyes to improve the rate of white light wireless communication. By conducting OOK coding-based communication tests on the prepared device, it is shown that the method and device proposed in the present invention can achieve high-speed white light wireless communication. Fig. 9 shown.

[0058] Example 5: This example illustrates how to prepare a white light emitting device that improves the white light wireless communication rate through fluorescence resonance energy transfer based on a blue light emitting diode chip, a green light coumarin 6 organic fluorescent dye, and a red light LR306 organic fluorescent dye, and completes the communication performance test: (1) Ultrasonic cleaning of blue light emitting diode chips using GaN as the light emitting material to ensure the cleanliness of the chip surface.

[0059] (2) The coumarin 6 organic fluorescent dye solution and the LR306 organic fluorescent dye solution were mixed at an acceptor-donor molar concentration ratio of 1.0, and the mixed solution was fully shaken to ensure that the two organic fluorescent dyes were evenly distributed in the mixed solution.

[0060] (4) Spin-coating the mixed solution mixed in a specific ratio onto a light-emitting diode chip to form a color conversion layer, so that the two organic fluorescent dyes are evenly mixed and distributed in the color conversion layer.

[0061] (5) Use polymethyl methacrylate to encapsulate the light-emitting diode chip and the color conversion layer.

[0062] This example shows a white light emitting device that improves the rate of white light wireless communication through fluorescence resonance energy transfer between green coumarin 6 organic fluorescent dye and red LR306 organic fluorescent dye, which illustrates the feasibility and universality of improving the rate of white light wireless communication through fluorescence resonance energy transfer proposed by the present invention.

[0063] Example 6: This example illustrates how to prepare a white light emitting device that improves the white light wireless communication rate through fluorescence resonance energy transfer based on a blue light emitting diode chip, a green light coumarin 6 organic fluorescent dye, and a red light CdSe / ZnS quantum dot, and completes the communication performance test: (1) Ultrasonic cleaning of blue light emitting diode chips using GaN as the light emitting material to ensure the cleanliness of the chip surface.

[0064] (2) A red light CdSe / ZnS quantum dot solution with uniform size distribution, high photoluminescence efficiency, and photoexcitation by a 350 nm to 480 nm light source was prepared using a hot injection method.

[0065] (3) The quantum dot solution prepared above and the coumarin 6 organic fluorescent dye solution were mixed at a donor-acceptor molar concentration ratio of 0.8, and the mixed solution was fully shaken to make the two fluorescent substances evenly distributed in the mixed solution.

[0066] (4) Spin-coating the mixed solution onto a light-emitting diode chip to form a color conversion layer, so that the two fluorescent substances are evenly mixed and distributed in the color conversion layer.

[0067] (5) Use polymethyl methacrylate to encapsulate the light-emitting diode chip and the color conversion layer.

[0068] This example shows a white light emitting device that improves the rate of white light wireless communication through fluorescence resonance energy transfer between green coumarin 6 organic fluorescent dye and red CdSe / ZnS quantum dots, which illustrates the feasibility and universality of the present invention's method of improving the rate of white light wireless communication through fluorescence resonance energy transfer.

[0069] The above-mentioned specific implementation methods are used to explain the present invention and are only preferred embodiments of the present invention, rather than limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A white light device with high communication rate, It is characterized in that include: A light emitting diode chip, used for emitting excitation light; A color conversion layer, located on the light-emitting diode chip, is used to generate white light through the excitation of the excitation light, wherein the color conversion layer includes at least two photoluminescent fluorescent materials, and fluorescence resonance energy transfer occurs between different photoluminescent fluorescent materials; The organic polymer encapsulation layer is located on the color conversion layer.

2. The high communication rate white light device according to claim 1, It is characterized in that The photoluminescent fluorescent material is II-VI semiconductor quantum dots, IV-VI semiconductor quantum dots, organic light-emitting quantum dots, organic light-emitting dye molecules, carbon quantum dots or silicon quantum dots.

3. The high communication rate white light device according to claim 1, It is characterized in that The distance between any photoluminescent materials in the color conversion layer is 2 nanometers to 10 nanometers.

4. The high communication rate white light device according to claim 1, It is characterized in that The color conversion layer comprises a donor material and an acceptor material, wherein the donor material and the acceptor material are different and both come from the photoluminescent fluorescent material, and the molar concentration ratio of the acceptor material to the donor material is 0.5-1.

5.

5. The high communication rate white light device according to claim 1, It is characterized in that The light emitting diode chip is a semiconductor with a light wave band of 380 nanometers to 480 nanometers, and is used to emit blue or purple excitation light.

6. The high communication rate white light device according to claim 1, It is characterized in that The material of the light emitting diode chip is gallium nitride, indium gallium nitride, aluminum nitride, zinc sulfide or zinc selenide.

7. The high communication rate white light device according to claim 1, It is characterized in that The light transmittance of the organic polymer encapsulation layer is greater than 80%.

8. The high communication rate white light device according to claim 1, It is characterized in that The thickness of the color conversion layer is 50 nanometers to 200 micrometers, and the thickness of the organic polymer encapsulation layer is 100 micrometers to 2 millimeters.

9. A method for preparing a high communication rate white light device according to any one of claims 1 to 8, It is characterized in that include: (1) ultrasonically cleaning the surface of the light-emitting diode chip, and at the same time mixing and shaking at least two photoluminescent material solutions to obtain a mixed solution; (2) spin coating the mixed solution on the cleaned light-emitting diode chip to form a color conversion layer; (3) A polymer encapsulation layer is formed on the color conversion layer to obtain a white light device with a high communication rate.

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