A single-layer blended polymer, a preparation method thereof and a manufacturing method of an organic light emitting diode

Abstract

This invention discloses a single-layer blended polymer, relating to the field of optoelectronic devices. It is formed by blending a shallow HOMO level polymer and a deep LUMO level polymer, with a blending ratio of 90:10 to 10:90. The invention also discloses a method for preparing this single-layer blended polymer, in which the shallow HOMO level polymer and the deep LUMO level polymer are blended to obtain the blended polymer. The generation ratio of the excitocomplex is controlled by adjusting the blending ratio of the shallow HOMO level polymer and the deep LUMO level polymer. Furthermore, this invention provides a method for fabricating an organic light-emitting diode (OLED): S1, blending the shallow HOMO level polymer and the deep LUMO level polymer to obtain a blended polymer solution; S2, dissolving the blended polymer solution in an organic solvent; S3, fabricating the light-emitting layer of the light-emitting device using a spin-coating or inkjet printing solution processing method. This invention controls the generation of the excitocomplex by adjusting the blending ratio of the two polymers, simplifying the processing flow and facilitating industrialization.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic device technology, and in particular to a single-layer blend polymer, its preparation method, and a method for fabricating organic light-emitting diodes. Background Technology

[0002] After years of development, organic light-emitting diodes (OLEDs) have been industrialized. White OLEDs can achieve full-color display using filters, serving as backlights for liquid crystal displays, and can also be used as white lighting sources. Polymer-based white light devices have attracted particular attention because they can be fabricated using wet processing techniques (such as inkjet printing), reducing costs and making them suitable for large-area flat panel displays. White light emission requires a broad emission spectrum, typically requiring three primary colors (blue, green, and red) or two complementary colors.

[0003] Currently, various methods and technologies can be used to achieve white light emission from small organic molecules and polymer materials. Small molecule white light diodes are generally achieved by sequentially depositing red, green, and blue light-emitting materials under high vacuum; polymer white light diodes typically utilize a blue light-emitting material as the main body, doped with appropriate amounts of red and green light-emitting materials, through monolayer solution processing. All of these white light devices utilize the superposition of light emitted from materials with different emission spectra; therefore, high-quality white light emission can only be achieved when the three primary colors or binary complementary color materials have good spectral complementarity. Due to the strong interaction between the two molecules in the excited state of excitocomplexes formed by intermolecular charge transfer, new excited states emerge, emitting emission spectra different from the original materials. Generally, the energy levels of the formed excitocomplexes are low, resulting in the loss of fine spectral structure, spectral broadening, and a redshift. Utilizing the broader and redshifted emission spectrum of the excitocomplexes, a monochromatic white light device with complementary excitocomplexes can be realized.

[0004] Junji Kido et al. (Adv. Mater. 2014, 26, 1612-1616) reported the formation of a blue-green light-emitting excitocomposite based on the hole transport material TAPC and the hole blocking material BTPS. They deposited a two-layer structure using thermal evaporation, utilizing the shallow HOMO level of TCTA and the deep LUMO level of BTPS to form an excitocomposite between the layers, achieving emission from the pure excitocomposite. Zhang Tianyou et al. (Appl. Mater. Interfaces 2014, 6, 11907-11914) used m-MTDATA and Bphen to form a yellow-green light-emitting excitocomposite, ultimately achieving a maximum current efficiency and a maximum external quantum efficiency of 20.9 cd / cm². 2And 7.79% of organic light-emitting devices. Zheng Yanru et al. (Macromolecules 2011, 44, 5968-5976) utilized the hole transport material DV-OM-TPD assembled by their own research group to form an effective red light excimer complex emission between it and a blue-green light-mixing emitting layer, obtaining a color coordinate of (0.32, 0.42) and a current efficiency of 5.28 cd / cm. 2 White light devices without red light materials.

[0005] In summary, current luminescence using excimer composites is based on the formation of interfaces between different organic layers. Multi-layer processing of polymer organic layers in solution fabrication is quite difficult, thus limiting the utilization of polymer-type excimer composites. Single-layer blending solution processing can solve the technological challenges of multi-layer solution processing and simultaneously enable the utilization of luminescence from polymer-type excimer composites. This simple and easy-to-implement processing method allows polymer-type excimer composites to be better applied in organic white light devices. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a single-layer blended polymer, its preparation method, and a method for fabricating organic light-emitting diodes. The invention involves fully contacting a shallow HOMO energy level polymer and a deep LUMO energy level polymer to form an excitocomplex. By controlling the proportion of the blended polymer, the proportion of excitocomplex formation is adjusted, ultimately obtaining a white light device that is complementary to blue light and the excitocomplex. This technical solution can simplify the processing technology and increase the selectivity of materials for preparing white light devices.

[0007] To achieve the above objectives, the present invention provides a single-layer blend polymer formed by blending a shallow HOMO level polymer and a deep LUMO level polymer, wherein the blending ratio of the shallow HOMO level polymer and the deep LUMO level polymer is 90:10 to 10:90.

[0008] In the above technical solution, the shallow HOMO energy level polymer is FATPA-C8OTPA, FATPA-C8OTPA, FATPA-C8F, or FATPA-EHCz.

[0009] In the above technical solution, the deep LUMO energy level polymer is FSO10, PFSO10, PPF-SO25, or PFSO5.

[0010] The present invention also provides a method for preparing a monolayer blended polymer, wherein a shallow HOMO level polymer and a deep LUMO level polymer are blended to obtain a blended polymer, wherein an excitocomplex will be formed in part during the blending process of the shallow HOMO level polymer and the deep LUMO level polymer, and the formation ratio of the excitocomplex is controlled by adjusting the blending ratio of the shallow HOMO level polymer and the deep LUMO level polymer.

[0011] This invention also provides a method for fabricating an organic light-emitting diode, comprising the following steps:

[0012] S1. Blend a shallow HOMO energy level polymer and a deep LUMO energy level polymer to obtain a blended polymer solution, wherein the blended polymer solution contains a blended polymer matrix and an excitocomplex.

[0013] S2. Dissolve the blended polymer solution in an organic solvent;

[0014] S3. Prepare the light-emitting layer of polymer light-emitting devices using solution processing methods such as spin coating or inkjet printing.

[0015] In the above technical solution, the organic solvent in step S2 is toluene, 1,2-xylene, or chlorobenzene.

[0016] In the above technical solution, the concentration of the organic solution is 10 mg / ml.

[0017] In the above technical solution, complementary color material is added to the blended polymer solution in step S1.

[0018] In the above technical solution, the complementary color material is Ir(piq)3 or MEH-PPV or

[0019] PPF-SO15-DHTBT10.

[0020] In the above technical solution, the content of the complementary color material is 0.05% to 1% based on the entire quality system.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. The two polymers selected in this invention have light HOMO and deep LUMO values, respectively. By utilizing the energy level characteristics of the two polymers, a suitable intermolecular distance is achieved through mixing, forming an effective excitocomplex. Since the optical band gap of the excitocomplex is narrower than that of the two blended polymers, the spectral emission exhibits a redshift compared to the emission of a single polymer. By adjusting the proportion of the blended polymers, the proportion of excitocomplex formation can be adjusted, thereby adjusting the emission ratio of the blended host and the excitocomplex. Ultimately, the emission of complementary binary white light from a monochromatic host and excitocomplex is obtained. By using the blended excitocomplex as the host and incorporating another complementary color material, and by adjusting the addition ratio, high-quality ternary white light emission can be achieved. This can optimize the performance of white light devices while also increasing the selectivity of organic light-emitting device materials.

[0023] 2. The polymer light-emitting device provided by the present invention uses two polymers as blending raw materials, which eliminates the need for molecular design, simplifies the raw material processing flow, and uses solution processing technology to prepare the light-emitting layer from the blended polymers. The preparation process is simple, the manufacturing cost is low, and it is conducive to industrialization. Attached Figure Description

[0024] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figures 1a-1f The chemical structural formulas are FATPA-C8OTPA, PFSO5, PFSO10, PPF-SO25, MEH-PPV, and Ir(piq)3, respectively.

[0026] Figure 2 These are structural diagrams of the organic light-emitting diodes used in each example;

[0027] Figure 3 This is an energy level diagram of an organic light-emitting diode (OLED) with a blend of PFSO10 and FATPA-C8OTPA and an OLED with a single polymer as the active layer.

[0028] Figure 4 These are the electroluminescence spectra of organic light-emitting diodes with PFSO10 and FATPA-C8OTPA blends and those with a single polymer as the active layer.

[0029] Figure 5 This is an energy level diagram of an organic light-emitting diode (OLED) with a PPF-SO25 and FATPA-C8F blend system and a single polymer as the active layer.

[0030] Figure 6 Electroluminescence spectra of PPF-SO25 and FATPA-C8F blend systems and organic light-emitting diodes with a single polymer as the active layer;

[0031] Figure 7 Energy level diagrams for PPF-SO25 and FATPA-EHCz blends and organic light-emitting diodes with a single polymer as the active layer;

[0032] Figure 8 Electroluminescence spectra of PPF-SO25 and FATPA-EHCz blends and organic light-emitting diodes with a single polymer as the active layer;

[0033] Figure 9 Energy level diagrams for PPF-SO25 and FATPA-C8OTPA blends and organic light-emitting diodes with a single polymer as the active layer;

[0034] Figure 10 Electroluminescence spectra of PPF-SO25 and FATPA-C8OTPA blend systems and organic light-emitting diodes with a single polymer as the active layer;

[0035] Figure 11 Energy level diagrams for organic light-emitting diodes (OLEDs) with PFSO5 and FATPA-C8F blends and single polymers as active layers;

[0036] Figure 12 These are the electroluminescence spectra of organic light-emitting diodes with PFSO5 and FATPA-C8F blends and those with a single polymer as the active layer.

[0037] Figure 13 Energy level diagram of an organic light-emitting diode with PFSO10, FATPA-C8OTPA and Ir(piq)3 system as active layer;

[0038] Figure 14 Electroluminescence spectra of organic light-emitting diodes with PFSO10, FATPA-C8OTPA and Ir(piq)3 system as active layers;

[0039] Figure 15 Energy level diagram of an organic light-emitting diode with PPF-SO25, FATPA-C8F and Ir(piq)3 system as active layer;

[0040] Figure 16 Electroluminescence spectra of organic light-emitting diodes with PPF-SO25, FATPA-C8F and Ir(piq)3 system as active layers;

[0041] Figure 17 Energy level diagram of an organic light-emitting diode with PPF-SO25, FATPA-EHCz and Ir(piq)3 system as active layer;

[0042] Figure 18 Electroluminescence spectra of organic light-emitting diodes with PPF-SO25, FATPA-EHCz and Ir(piq)3 system as active layers;

[0043] Figure 19 Electroluminescence spectra of organic light-emitting diodes with PFSO10, FATPA-C8OTPA and MEH-PPV systems as active layers;

[0044] Figure 20 Electroluminescence spectra of organic light-emitting diodes with PFSO10, FATPA-C8OTPA and PPF-SO15-DHTBT10 systems as active layers;

[0045] Figure 21 This is a schematic diagram of the structure of an excitocomplex formed by blending a shallow HOMO level polymer and a deep LUMO level polymer. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0047] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0048] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0050] Existing organic light-emitting diodes (OLEDs) that utilize excitation complexes for light emission are all multilayer structures formed by excitation complexes at the interfaces between different layers. The complexity of these multilayer structures makes fabrication difficult; furthermore, for solution-processed OLEDs, interlayer erosion easily occurs during the fabrication of multilayer structures, leading to a degradation in device performance.

[0051] The purpose of this invention is to overcome the complexity of fabrication processes for multilayer devices by utilizing a blended monolayer structure to form an excimer complex for light emission. By blending two polymers capable of forming an excimer complex, the two polymers can be brought into full contact, resulting in more efficient excimer complex formation and simplified processing.

[0052] Another objective of this invention is to adjust the proportion of excitocomplex formation by controlling the proportion of blended polymers, thereby ultimately obtaining a white light device that is complementary to blue light and excitocomplex, thus increasing the selectivity of materials for preparing white light devices.

[0053] Therefore, this technical solution provides a single-layer blend polymer formed by blending a shallow HOMO level polymer and a deep LUMO level polymer, wherein the blending ratio of the shallow HOMO level polymer to the deep LUMO level polymer is 90:10 to 10:90. The shallow HOMO level polymer is...

[0054] FATPA-C8OTPA, FATPA-C8OTPA, FATPA-C8F, or FATPA-EHCz. Deep LUMO level polymers are PFSO10, PPF-SO25, or PFSO5.

[0055] Therefore, this technical solution provides a method for preparing a single-layer blend polymer, which involves light-colored...

[0056] HOMO level polymers and deep LUMO level polymers are blended to obtain blended polymers. During the blending process, some excitocomplexes will form between the shallow HOMO level polymer and the deep LUMO level polymer. The formation ratio of excitocomplexes is controlled by adjusting the blending ratio of the shallow HOMO level polymer to the deep LUMO level polymer. Preferably, the blending ratio of the shallow HOMO level polymer to the deep LUMO level polymer is 90:10 to 10:90. (See also...) Figures 1a-1f The shallow HOMO energy level polymer can be FATPA-C8OTPA or FATPA-C8OTPA or

[0057] FATPA-C8F or FATPA-EHCz, with deep LUMO level polymers being FSO10, PFSO10, PPF-SO25, or PFSO5.

[0058] Please see Figure 21 The two polymers selected in this invention possess shallow HOMO and deep LUMO energy levels, respectively. Utilizing the energy level characteristics of the two polymers, mixing them to achieve a suitable intermolecular distance allows for the formation of an effective exciton complex. The specific light-emitting process is as follows: electrons and holes are injected and transported to the active layer via the cathode and anode, respectively. Due to the energy level characteristics of the blended polymers, most electrons are confined to the LUMO of the deep LUMO polymer, while most holes are confined to the HOMO of the shallow HOMO polymer. Therefore, during exciton radiative transitions, due to the formation of the exciton complex, some excitons will have electrons migrating back from the LUMO of the deep LUMO polymer to the HOMO of the shallow HOMO polymer, emitting photons. Therefore, this exciton complex formed by blending shallow HOMO and deep LUMO polymers can be applied to the light-emitting layer of light-emitting devices such as organic light-emitting diodes and flat panel displays.

[0059] Because the optical band gap of the excimer complex is narrower than that of the two blended polymers, its spectral emission exhibits a redshift compared to that of the single polymer. By adjusting the proportion of the blended polymers, the proportion of the excimer complex can be adjusted, thereby regulating the emission ratio between the blended host and the excimer complex, ultimately achieving the emission of complementary binary white light from the monochromatic host and excimer complex.

[0060] Therefore, the process of fabricating the light-emitting layer of an organic light-emitting diode includes the following steps:

[0061] S1. A light HOMO level polymer and a deep LUMO level polymer are blended to obtain an excimer complex solution. The production ratio of the excimer complex can be controlled by adjusting the blending ratio of the light HOMO level polymer and the deep LUMO level polymer, thereby obtaining binary complementary white light of the excimer complex type and optimizing white light performance. Preferably, the blending ratio of the light HOMO level polymer and the deep LUMO level polymer is 90:10 to 10:90. The light HOMO level polymer is FATPA-C8OTPA, FATPA-C8OTPA, FATPA-C8F, or FATPA-EHCz. The deep LUMO level polymer is FSO10, PFSO10, PPF-SO25, or PFSO5. Furthermore, a complementary color material is preferably added to the blended polymer solution. The complementary color material can be...

[0062] Ir(piq)3, MEH-PPV, or PPF-SO15-DHTBT10, etc., are not limited to these. The content of the complementary color material is preferably 0.05% to 1% based on the entire mass system. In this technical solution, by adjusting the blending ratio of the light HOMO energy level polymer and the deep LUMO energy level polymer and the amount of complementary color material added, the luminescence performance of white light is optimized, thereby achieving high-quality white light emission.

[0063] S2. Dissolve the blended excitosome complex in an organic solvent, which can be toluene, p-xylene, or chlorobenzene, and the concentration of the organic solution is 10 mg / ml.

[0064] S3. Prepare the light-emitting layer of organic light-emitting diodes using solution processing methods such as spin coating or inkjet printing.

[0065] Example 1: This example uses two blue polymer luminescent materials, one with a deep LUMO energy level (PFSO10) and the other with a shallow HOMO energy level (FATPA-C8OTPA), as materials for forming the excimer complex. First, the two polymers were dissolved in p-xylene to prepare the required solutions. The two polymers were then mixed according to the following mixing ratios: PFSO10:FATPA-C8OTPA = 100:0, 90:10, 70:30, 50:50, and 0:100. The active layer of the organic light-emitting diode was prepared using a solution spin-coating method. (See [link to relevant documentation]). Figure 2 The device structure of a polymer organic light-emitting diode (OLED) is ITO / PDEOT:PSS (40nm) / active layer (80nm) / CsF (1.5nm) / Al (120nm). From... Figure 3It is known that the two selected polymers have a good HOMO and LUMO energy level difference, which can form a good exciton complex for luminescence. When electrons are injected from the cathode Al, most of them are confined to the LUMO of PFSO10, while when holes are injected from the anode ITO, most of them are confined to the HOMO of FATPA-C8OTPA. Some of the electrons and holes form excitons on the single polymer and undergo radiative transitions to emit blue light, while most of the electrons and holes form excitons different from those of the single polymer due to the formation of the exciton complex, thus emitting a new spectrum when radiative transitions occur.

[0066] from Figure 4 It is known that the emission spectra of the two individual polymers are blue light. A new emission peak appears in the EL spectrum of the blended luminescent layer, located at approximately 520 nm. This new emission peak is redshifted by about 80 nm compared to the emission of the blue material and has a wider emission peak. The new emission peak is due to the formation of a lower-energy excitopolymer complex between PFSO10 at the deep LUMO energy level and FATPA-C8OTPA at the shallow HOMO energy level, resulting in a redshift and emission of green light. By adjusting the ratio of PFSO10 to FATPA-C8OTPA, the emission ratio of the blue material and the excitopolymer complex is balanced, resulting in white light emission from the polymer-type excitopolymer complex. The data in Table 1 show that white light emission can be obtained from both polymers at three different blending ratios, and the color coordinates are relatively close to the ideal white light color coordinates (0.33, 0.33).

[0067] Example 2: This example uses two blue polymer luminescent materials, one with a deep LUMO level (PPF-SO25) and the other with a shallow HOMO level (FATPA-C8F), as materials to form the excimer complex. The active layer of an organic light-emitting diode (OLED) was prepared by dissolving the two polymers in p-xylene at a mass ratio of 50:50 to form a clear solution and then spin-coating the solution. The device structure is the same as in Example 1. Figure 5 It can be seen that both polymers exhibit a large energy level difference in both HOMO and LUMO, which facilitates the confinement of electrons and holes to different polymers and the formation of effective excitocomplexes. From Figure 6 It can be seen that the device derived from the polymer blend exhibits a wide emission spectrum, with the largest emission peak around 519 nm. This peak shows a significant redshift compared to the single blue-light-emitting polymer, indicating the formation of an excimer complex between the two polymers. In addition to the peak around 519 nm, the spectrum also shows a shoulder peak around 451 nm, which likely represents the emission of the narrower bandgap polymer PPF-SO25. This blend system yielded a white light device with a CRI of (0.296, 0.443), representing an excimer complex-type white light system that closely approximates ideal white light emission.

[0068] Example 3: In this example, two blue polymer luminescent materials with deep LUMO levels (PPF-SO25) and shallow HOMO levels (FATPA-EHCz), respectively, were selected as materials for forming the excimer complex. The active layer of an organic light-emitting diode was prepared by dissolving the two polymers in p-xylene at a mass ratio of 50:50 to form a clear solution and then spin-coating the solution. The device structure was the same as in Example 1. Figure 7 It can be seen from this that there is a large energy difference between the HOMO and LUMO energy levels of polymers PPF-SO25 and FATPA-EHCz, which is conducive to the formation of a better excitosome complex for emission. From Figure 8 It can be seen that the device has a broad blue-green light emission, with an emission peak of approximately 526 nm. This indicates that the system can also form a good excimer complex emission, with a shoulder peak in addition to the 526 nm emission peak. This shoulder peak belongs to the emission of the main blue light material. This blend system yielded a white light device with a CRI of (0.311, 0.504).

[0069] Example 4: This example uses two blue polymer luminescent materials, one with a deep LUMO level (PPF-SO25) and the other with a shallow HOMO level (FATPA-C8OTPA), as materials to form the excimer complex. The active layer of an organic light-emitting diode (OLED) is prepared by dissolving the two polymers in p-xylene at a mass ratio of 50:50 to form a clear solution and then spin-coating the solution. The device structure is the same as in Example 1. Figure 9 It can be seen that PPF-SO25 and FATPA-C8OTPA have a large energy level difference in HOMO and LUMO, which can form an effective excitocomplex. Figure 10 This is the electroluminescence spectrum of this example. The spectrum shows a broad emission peak at approximately 555 nm, which belongs to the emission of the excitopolymer complex formed by PPF-SO25 and FATPA-C8OTPA. In addition, there is a shoulder peak at approximately 445 nm, belonging to the emission of the blue light-emitting material. This system yielded a white light device with a CRI of (0.398, 0.511) and a color temperature of 4295°C.

[0070] Example 5: This example uses two blue polymer light-emitting materials, one with a deep LUMO level (PFSO5) and the other with a shallow HOMO level (FATPA-C8F), as materials to form the excimer complex. The active layer of an organic light-emitting diode (OLED) was prepared by dissolving the two polymers in p-xylene at a mass ratio of 50:50 to form a clear solution and then spin-coating the solution. The device structure is the same as in Example 1. Figure 11 It can be seen that the two blue polymers possess a good HOMO and LUMO energy level difference, which is conducive to the formation of a good excitopolymer complex. From Figure 12It can be seen that the blend device has a broad electroluminescent emission spectrum in the blue-green light band. This emission peak belongs to the excimer complex. In addition, there is a shoulder peak at around 445 nm, which belongs to the blue polymer emission. The CRI of the device obtained by this blend system is (0.225, 0.344).

[0071] Example 6: Two blue polymeric luminescent materials with deep LUMO levels (PFSO10) and shallow HOMO levels (FATPA-C8OTPA) were selected as the luminescent materials for forming the exciton complex, and red material Ir(pig)3 was used as the complementary color material. PFSO10, FATPA-C8OTPA, and Ir(pig)3 were dissolved in p-xylene at mass ratios of 70:30:0 and 70:30:0.1 to prepare a clear mixed solution. The active layer of the organic light-emitting diode was prepared by solution spin-coating. The device structure of the polymeric organic light-emitting diode was ITO / PDEOT:PSS (40nm) / active layer (80nm) / CsF (1.5nm) /

[0072] Al (120nm). From Figure 14 It can be seen that the binary blue polymer blend device has two emission peaks, belonging to the blue polymer PFSO10 and the excimer compound, respectively. After adding an appropriate amount of red light-emitting material to the excimer compound substrate, the device's electroluminescence spectrum shows three emission peaks: the blue portion is from the blue polymer PFSO10, the green portion is from the excimer compound, and the red portion is from the red material Ir(piq)3. The spectrum exhibits a broad emission range in the visible light region. Doping the excimer compound substrate with an appropriate amount of red light-emitting material to achieve incomplete energy transfer from the substrate material yields a white light device with a CIE of (0.347, 0.399). This device has a display index of 86, a significant improvement over the excimer compound white light device, making it a suitable candidate for white light illumination.

[0073] Example 7: PPF-SO25, a polymer with deep LUMO energy levels, and FATPA-C8F, a polymer with shallow HOMO energy levels, were selected as the host materials for the exciton compound. An appropriate amount of red light-emitting material Ir(piq)3 was incorporated into the host material to form a ternary complementary white light emission. A mixture of PPF-SO25, FATPA-C8F, and Ir(piq)3 in a mass ratio of 50:50:0.1 was dissolved in p-xylene, and the active layer of an organic light-emitting diode was prepared using a solution spin-coating method. The device structure was the same as that in Example 1. Figure 15 It can be seen that there is a large energy level difference between the HOMO and LUMO of the two blue polymers, which can form an effective excitocomplex for emission. From Figure 16The results show that the blend matrix exhibits significant excitopolymer emission, with a broad emission range in the blue-green light region. After adding Ir(piq)3, the device's electroluminescence spectrum shows strong emission in the red light region, covering the entire visible light spectrum. The white light device using the ternary blend as the active layer has a CIE of (0.439, 0.387) and a CCT of 2808, indicating it is a high-quality white light device.

[0074] Example 8: Using PPF-SO25 (a polymer with deep LUMO energy levels) and FATPA-EHCz (a polymer with shallow HOMO energy levels) as the main materials of the excimer composite, white light emission of the ternary blend excimer composite was achieved by adding an appropriate amount of red light-emitting material Ir(piq)3. A mixture of PPF-SO25, FATPA-EHCz, and Ir(piq)3 in a mass ratio of 50:50:0.1 was dissolved in p-xylene, and the active layer of an organic light-emitting diode was prepared using a solution spin-coating method. The device structure was the same as in Example 6. Figure 17 It can be seen that the energy level characteristics of the blue light polymers PPF-SO25 and FATPA-EHCz can form a good excitocomplex. Figure 18 The electroluminescence spectrum also confirms this viewpoint, showing that the two blue light blends exhibit strong excito-complex emission in the green light band. Adding Ir(piq)3 to the blue light blends resulted in a spectrum covering the red, green, and blue bands, achieving incomplete energy transfer and producing good white light emission. The white light device achieved a CIE of (0.511, 0.383) and a CCT of 1929, demonstrating good white light emission.

[0075] Example 9: A blend of PFSO10 and FATPA-C8OTPA in a mass ratio of 70:30 was selected as the main material for an organic light-emitting diode (OLED). 1% (by mass) of the red light-emitting material MEH-PPV (PFSO10) was incorporated into the blend to improve the luminescence performance of the binary white light-emitting device, thus realizing a ternary white light-emitting device of the excimer compound type. A white light-emitting diode device was fabricated using the above blend as the emitting layer, and the device structure was the same as in Example 6. Figure 19 As can be seen from the addition of MEH-PPV, the excimer composite host material achieves partial energy transfer, and the electroluminescence spectrum covers most of the visible light region. White light devices using ternary blend polymers as the active layer achieve CIE and CCT values ​​of (0.389, 0.403) and 3954, respectively, realizing high-quality white light devices.

[0076] Example 10: A blend of PFSO10 and FATPA-C8OTPA in a mass ratio of 70:30 was also used as the main material for the organic light-emitting diode (OLED). 1% (by mass) of red light-emitting material PPF-SO15-DHTBT10, doped with PFSO10, was incorporated into the blend. The blended polymer served as the active layer of the white OLED, and the device structure was identical to that of Example 6. Figure 20 The image shows the electroluminescence spectrum of the organic light-emitting diode (OLED) of this system. The white light device with added PPF-SO15-DHTBT10 exhibits significantly improved emission in the red light region compared to the binary excimer compound. The CIE and CCT of the ternary blend white light device are (0.428, 0.383) and 2979, respectively, achieving high-quality white light emission.

[0077] Appendix 1

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[0079] Appendix 2

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[0081] Appendix 3

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[0083] Appendix 4

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[0085] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A single-layer blend polymer, characterized in that, It is formed by blending a shallow HOMO level polymer and a deep LUMO level polymer, wherein the blending ratio of the shallow HOMO level polymer and the deep LUMO level polymer is 90:10 to 10:

90. The shallow HOMO energy level polymer is FATPA-C8OTPA; The deep LUMO energy level polymer is PFSO10, PPF-SO25, or PFSO5; The above-mentioned method for preparing monolayer blended polymers involves blending a shallow HOMO level polymer and a deep LUMO level polymer to obtain a blended polymer. During the blending process, some of the shallow HOMO level polymer and the deep LUMO level polymer will form excitocomplexes. The ratio of excitocomplex formation can be controlled by adjusting the blending ratio of the shallow HOMO level polymer and the deep LUMO level polymer.

2. A method for fabricating an organic light-emitting diode, characterized in that, Includes the following steps: S1. Blend a shallow HOMO level polymer and a deep LUMO level polymer to obtain a blended polymer solution, wherein the blended polymer solution contains a blended polymer matrix and an excitocomplex, and the blending ratio of the shallow HOMO level polymer and the deep LUMO level polymer is 90:10~10:

90. The shallow HOMO energy level polymer is FATPA-C8OTPA; The deep LUMO energy level polymer is PFSO10, PPF-SO25, or PFSO5. S2. Dissolve the blended polymer solution in an organic solvent; S3. Prepare the light-emitting layer of polymer light-emitting devices using solution processing methods such as spin coating or inkjet printing; In step S1, a complementary color material is added to the blended polymer solution. The complementary color material is Ir(piq)3, MEH-PPV, or PPF-SO15-DHTBT10, and the content of the complementary color material is 0.05% to 1%.

3. The method for fabricating an organic light-emitting diode according to claim 2, characterized in that, The organic solvent in step S2 is toluene, 1,2-xylene, or chlorobenzene.

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