Organic long-lasting luminescent material with narrow-band emission characteristic and application of organic long-lasting luminescent material

Abstract

The invention discloses an organic long-lasting luminescent material with a narrow-band emission characteristic and application thereof, and belongs to the field of organic long-lasting luminescent materials. The donor comprises one or more of the following materials; the receptor includes:.

Description

Technical Field

[0001] This invention relates to the field of organic long-lasting luminescent materials, specifically to an organic long-lasting luminescent material with narrow-band emission characteristics and its applications. Background Technology

[0002] Organic long-lasting luminescence (OLPL) materials refer to a class of materials that continue to emit light even after the removal of the external excitation source, with afterglow lasting for tens of minutes or even tens of hours. They have wide applications in high-contrast bioimaging, emergency lighting, anti-counterfeiting, and information encryption. Reports of organic long-lasting luminescence can be traced back to the 1930s, when Clapp observed that tetraphenylsilane and its derivatives emitted a bright afterglow lasting approximately 23 seconds in a crystalline state at room temperature, with colors ranging from blue to green. At that time, he believed the luminescence was mainly due to the presence of trace impurities in the crystal. In 2013, the Adachi research group in Japan successfully achieved efficient and persistent afterglow in air using pure organic amorphous host-guest materials. By using amorphous rigid steroidal compounds as the host matrix, they significantly reduced the quenching of long-lived triplet excitons interacting with the host matrix and oxygen. Furthermore, the deuteration of the guest matrix reduced the nonradiative decay rate of the material. In 2015, our research group proposed a fundamental design principle for controlling exciton lifetime in organic materials. This principle involves stabilizing triplet excitons through molecular H-aggregation, providing an effective pathway for ultralong visible lifetime luminescence of various pure organic molecules at room temperature. By adjusting the molecular structure, the color of ultralong phosphorescence can be tuned from green (515 nm) to red (644 nm), achieving a luminescence lifetime as high as 1.35 s under ambient conditions, several orders of magnitude longer than that of traditional organic fluorophores. The rapid development of OLPL materials can be traced back to 2017, when Adachi and colleagues reported an OLPL lasting up to one hour through organic donor-acceptor (DA) hybridization. Since then, various high-performance multicolor OLPL material systems, including crystalline, amorphous host-guest small molecules, and polymers, have been developed. However, current OLPL materials mainly rely on DA-addition complex strategies. Due to inherent charge transfer characteristics, this basic design paradigm inherently leads to a broad emission spectrum and limited color tunability of OLPL materials, which greatly limits their practical applications. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention proposes an organic long-lasting luminescent material with narrowband emission characteristics and its applications.

[0004] The objective of this invention can be achieved through the following technical solutions: A first aspect of the present invention relates to a luminescent material, comprising an acceptor and a donor; The donor includes one or more of the following materials: ; The receptors include: .

[0005] Optionally, the molar ratio of the binary dopant t-DABNA to DBTSPO is 0.01:1; the molar ratio of the binary dopant BNCzPXZ to DBTSPO is 0.33:1; the molar ratio of the binary dopant TPABO-DICz to DBTSPO is 0.33:1; and the molar ratio of the binary dopant BN3 to DBTSPO is 0.5:1.

[0006] Optionally, the molar ratio of the ternary dopant t-DABNA, PPT and m-MTDATA is 0.01:1:0.01; the molar ratio of the ternary dopant BNCzPXZ, PPT and m-MTDATA is 0.005:1:0.005; and the molar ratio of the ternary dopant BN3, PPT and m-MTDATA is 0.005:1:0.005.

[0007] Optionally, it also includes a hole trapping agent with the following structural formula: .

[0008] A second aspect of the present invention relates to a product having a fluorescent label, comprising the aforementioned luminescent material.

[0009] A third aspect of the present invention relates to a method for preparing a luminescent material, comprising the following steps: The donor and acceptor materials are heated to a molten state and then solidified to obtain the luminescent material. The donor includes one or more of the following materials: ; The receptors include: .

[0010] Optionally, the temperature of the molten state is 150 to 250 degrees Celsius.

[0011] Optionally, the donor and acceptor are ground before melting, and the grinding time is ≥10 s.

[0012] Optionally, oxygen is isolated during the melting process.

[0013] A fourth aspect of the present invention relates to the application of the above-described luminescent material or the luminescent material prepared by the above-described preparation method in emergency lighting products, afterglow display products, and anti-counterfeiting encryption labels.

[0014] The beneficial effects of this invention are: This invention overcomes the problems of excessively broad emission spectra and limited color tunability in traditional excimer complex systems based on host-guest doping. By rationally constructing and using multiple resonant thermally activated delayed fluorescent materials as donors, a full-color narrowband OLPL was achieved, with a maximum duration of up to 44 hours. The developed organic long-lasting luminescent material with narrowband emission characteristics has broad application prospects in emergency lighting, afterglow displays, and anti-counterfeiting encryption. Attached Figure Description

[0015] The invention will now be further described with reference to the accompanying drawings.

[0016] Figure 1 The images show the steady-state photoluminescence and delayed photoluminescence spectra of different host-guest binary doped systems in Example 1.

[0017] Figure 2 This is a kinetic lifetime diagram of different host-guest binary doped systems in Example 1.

[0018] Figure 3 The images show the OLPL spectra of different host-guest binary doped systems in Example 1.

[0019] Figure 4 The image shows the afterglow diagrams of different host-guest binary doped systems in Example 1.

[0020] Figure 5 The optimized concentrations of BN3, PPT, and m-MTDATA for the ternary doped system are shown, along with the best steady-state photoluminescence and delayed photoluminescence spectra of the ternary doped system.

[0021] Figure 6 The OLPL spectra of the optimal ternary doped system BN3, PPT, and m-MTDATA are shown.

[0022] Figure 7 The afterglow diagrams of PPT and m-MTDATA for the optimal ternary doped system BN3.

[0023] Figure 8 The optimal ternary doped systems are BN3, PPT, and m-MTDATA; the ternary doped systems are BN3, DBTSPO, and m-MTDATA; and the kinetic lifetime comparison diagrams of the binary doped systems BN3 and DBTSPO are shown.

[0024] Figure 9 For afterglow display applications of organic long-lasting luminescent materials with narrow-band emission characteristics. Detailed Implementation

[0025] 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 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.

[0026] Unless otherwise specified, all materials and reagents required for the following examples are commercially available.

[0027] It should be noted that some of the materials in the embodiments of this application are from the following sources: DBTSPO and PPT were synthesized according to the method described in the literature "Developing stable organic radical anions to achieve longpersistent luminescence for afterglow lighting"; TPABO-DICZ was synthesized according to the method described in the literature "Precise Regulation of Multiple Resonance Distribution Regions of a B,N-Embedded Polycyclic Aromatic Hydrocarbon to Customize Its BT2020 Green Emission"; BNCzPXZ was purchased from Zhengzhou Alpha; t-DABNA and BN3 were purchased from PURE Materials; m-MTDATA was purchased from Hanfeng Materials.

[0028] Example 1 The weighed 2 mg t-DABNA and 118 mg DBTSPO; 0.85 mg BNCzPXZ and 180 mg DBTSPO; 1.35 mg TPABO-DICz and 180 mg DBTSPO; and 2.68 mg BN3 and 180 mg DBTSPO were thoroughly ground and placed into the custom-made grooves. The groove is placed in a glove box and heated to melt at a temperature of 150°C (DBTSPO is the main body, and its melting temperature is 150°C). Seal the heated and melted sample with adhesive and cure it with ultraviolet light.

[0029] Example 2 The weighed 1.1 mg t-DABNA, 100 mg PPT and 1.34 mg m-MTDATA; 0.47 mg BNCzPXZ, 100 mg PPT and 0.68 mg m-MTDATA; 1 mg BN3, 100 mg PPT and 0.35 mg m-MTDATA were thoroughly ground and placed into the custom-made grooves. The groove is placed in a glove box and heated to melt at a temperature of 250℃ (PPT is the main body, and its melting temperature is 250℃). Seal the heated and melted sample with adhesive and cure it with ultraviolet light.

[0030] Example 3 The weighed 1 mg BN3, 100 mg DBTSPO, and 0.35 mg m-MTDATA were thoroughly ground and placed into the custom-made grooves; The groove is placed in a glove box and heated to melt at a temperature of 150°C (DBTSPO is the main body, and its melting temperature is 150°C). Seal the heated and melted sample with adhesive and cure it with ultraviolet light.

[0031] To verify the performance of the luminescent material prepared in the above embodiments, the following experimental methods were used: Steady-state photoluminescence and delayed photoluminescence spectra of different host-guest doped systems were tested on an FLS1000 using xenon lamps and microsecond lamps, respectively.

[0032] The kinetic lifetime plots of different host-guest doped systems were tested on an FLS1000 using a 365 nm UV lamp.

[0033] LPL spectra of different host-guest doped systems were tested on an FLS1000 using a 365 nm UV lamp.

[0034] Afterglow images of different host-guest doped systems were captured using a Canon EOS R5 with a 365 nm UV lamp.

[0035] Experimental results The optimal doping ratios of t-DABNA, BNCzPXZ, TPABO-DICZ, and BN3-doped DBTPSO films were 1, 0.33, 0.33, and 0.5 mol%, respectively, all exhibiting narrow-band SSPL and delayed PL, which originated from the multiple resonance thermally activated delayed phosphor donor. After 1 min of irradiation with a 365 nm UV lamp, the t-DABNA, BNCzPXZ, TPABO-DICZ, and BN3-doped DBTPSO films showed blue, green, yellow, and red OLPL, with emission peaks at ~481, ~541, ~527, and ~611 nm, respectively, and afterglow lifetimes lasting for tens of minutes. With the introduction of m-MTDATA, the full width at half maximum (FWHM) of BN3, PPT, and m-MTDATA decreased to as low as 48 nm, with the longest duration reaching 44 h.

[0036] In summary, we proposed an effective strategy to achieve full-color narrowband OLPL by rationally constructing and using multi-resonance thermally activated delayed fluorescent emitters as donors. The longest duration can reach 44 hours. The developed organic long-continuous luminescent material with narrowband emission characteristics has broad application prospects in emergency lighting, afterglow display and anti-counterfeiting encryption.

[0037] 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.

[0038] Specifically, regarding the experimental results shown in the figure, Figure 1 In the figure, steady-state photoluminescence (SSPL) and delayed photoluminescence (DPL) spectra of four different donor / acceptor binary doped systems are shown. These systems all exhibit narrow-band characteristics, and the delayed luminescence originates from the multiple resonant thermally activated delayed fluorescence material (MR-TADF) donor itself.

[0039] Figure 3 This further confirms that the organic long continuous emission (OLPL) of the binary system has narrow-band emission characteristics.

[0040] Figure 4 This study visually demonstrates the successful achievement of full-color OLPL by adjusting the MR-TADF donor. After 1 minute of UV irradiation, these systems exhibited OLPL in blue (t-DABNA), green (BNCzPXZ), yellow (TPABO-DICz), and red (BN3).

[0041] Figure 5 , Figure 6 and Figure 7 The experimental results demonstrate that the duration of OLPL was significantly improved by introducing a third component—the hole trapping agent m-MTDATA.

[0042] Specifically, Figure 5 The left figure in the middle shows a schematic diagram of the kinetic lifetime of BN3 / PPT / m-MTDATA under different doping ratios; Figure 5 The right figure shows the SSPL and Delayed PL spectra of the optimal ternary system (BN3 / PPT / m-MTDATA), demonstrating that its narrowband emission characteristics are maintained even with the introduction of a hole trap. Figure 6 This further confirms that the full width at half maximum (FWHM) of the ternary system can still be as low as 48 nm.

[0043] Figure 6 The changes in the OLPL spectrum of the optimized ternary doped system (BN3 / PPT / m-MTDATA) over long time scales are presented in detail. The results show that the afterglow duration of this system can be extended to 44 hours (h), and the emission signal can still be detected during this ultra-long lifetime.

[0044] Figure 7 (and combination) Figure 6 The spectral data clearly demonstrate that the ternary system still exhibited visually recognizable luminescence after 27 hours.

[0045] like Figure 8 As shown, the decay curve (blue curve) of the doped system (BN3 / m-MTDATA / PPT) is significantly better than all other systems, especially the binary system (BN3 / DBTSPO, green curve) without the introduction of m-MTDATA. The decay rate of BN3 / m-MTDATA / DBTSPO is also significantly slower than that of BN3 / DBTSPO, which shows that the introduction of m-MTDATA can significantly improve the performance of the luminescent material.

[0046] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A luminescent material, comprising an acceptor and a donor; the donor comprises one or more of the following materials: ； the acceptor comprises: 。 2. The light emitting material of claim 1, wherein, the molar ratio of the binary doping of t-DABNA and DBTSPO is 0.01:1; the molar ratio of the binary doping of BNCzPXZ and DBTSPO is 0.33:1; the molar ratio of the binary doping of TPABO-DICz and DBTSPO is 0.33:1; the molar ratio of the doping of BN3 and DBTSPO is 0.5:

1.

3. The light emitting material of claim 1, wherein, the molar ratio of the ternary doping of t-DABNA, PPT and m-MTDATA is 0.01:1:0.01; the molar ratio of the ternary doping of BNCzPXZ, PPT and m-MTDATA is 0.005:1:0.005; the molar ratio of the ternary doping of BN3, PPT and m-MTDATA is 0.005:1:0.

005.

4. The light emitting material of claim 1, wherein, a hole-trapping agent with the structural formula: 。 5. A product with fluorescent identification, comprising the luminescent material of any one of claims 1-4.

6. A preparation method of a luminescent material, comprising the following steps: heating the donor and acceptor materials to a molten state, and solidifying to obtain the luminescent material; the donor comprises one or more of the following materials: ； the acceptor comprises: 。 7. The method of claim 6, wherein the method further comprises the step of: the temperature of the molten state is 150-250 degrees Celsius. ​ 8. The method of claim 6, wherein the method further comprises the step of: the donor and acceptor are ground before being molten, and the grinding time is ≥10 s. ​ 9. The method for preparing the luminescent material according to claim 6, characterized in that, the molten process is carried out in an oxygen-free environment.

10. The luminescent material of any one of claims 1-4 or the luminescent material prepared by the preparation method of any one of claims 6-9, in the application of emergency lighting products, residual display products and anti-counterfeiting encryption identification.

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