CN106810899B

CN106810899B - Multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye, and synthesis method and application thereof

Info

Publication number: CN106810899B
Application number: CN201710078700.6A
Authority: CN
Inventors: 许辉; 张静; 韩春苗
Original assignee: Heilongjiang University
Current assignee: Heilongjiang University
Priority date: 2017-02-14
Filing date: 2017-02-14
Publication date: 2020-11-17
Anticipated expiration: 2037-02-14
Also published as: CN106810899A

Abstract

A multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye, a synthetic method and application thereof relate to a multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye, a synthetic method and application thereof. The invention aims to solve the technical problem that the performance and stability of a device are poor due to a quenching effect caused by accumulation of excitons of phosphorescent and thermally excited delayed fluorescent dyes. The dye is formed by taking DPPPPPO, DPNAPO or DPAPO as a ligand and coordinating with CuX, and the synthesis method is as follows: mixing 1mmol of polydentate phosphine ligand, CuX and DCM, reacting for 1 hour at 40 ℃, spin-drying, dissolving in DCM, and respectively adding 5-10 mmol of H under ice-water bath₂O₂After reacting for 5 hours, extracting with sodium bisulfite, taking the lower layer, drying with anhydrous sodium sulfate, spin-drying, and purifying by chromatography to obtain the final product; in the invention, the multidentate coordination is utilized to increase the spin-orbit coupling of the ligand to the metal, and the charge transfer from the halogen to the ligand is regulated by the halogen, so that the phosphorescence emission of the copper complex is enhanced.

Description

Multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye, and synthesis method and application thereof

Technical Field

The invention relates to a multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye, a synthetic method and application thereof.

Background

The research on organic light emitting materials and devices has attracted much attention and intensive research. Organic light-emitting diodes (OLEDs), which are referred to as third-generation flat panel display and lighting technologies, have outstanding advantages in energy saving and environmental protection, and currently, a commonly used method is to use phosphorescent dyes to construct electrophosphorescence, but heavy metals related to phosphorescent dyes are expensive and pollute the environment, and other materials are urgently needed to be used for replacement. Recently, a Thermally Activated Delayed Fluorescence (TADF) technology called a third generation organic electroluminescent technology has been greatly developed in order to effectively utilize Singlet (S, S) generated during electroluminescence₁) And Triplet (Triplet, T)₁) Excitons, as exciton distribution is subject to statistical probability in the presence of electron,i.e. approximately 25% and 75% singlet and triplet excitons, respectively. Therefore, the external quantum efficiency of the fluorescent device based on Electroluminescence (EL) of the ITO glass substrate does not exceed 5%. However, all excitons may be concentrated to the radiating T by intersystem or reverse intersystem crossing₁Or S₁Excited state, thereby achieving 100% exciton utilization. Exciton utilization is the basis for achieving high performance OLEDs, with only one electroluminescent process being Fluorescent (FL), Phosphorescent (PH), and thermally-excited delayed fluorescence. Such single mode radiation will inevitably produce S for TADF and PH, respectively, even if the singlet or triplet radiative transition processes emit light₁And T₁Accumulation of excitons. Thus exacerbating exciton quenching and device efficiency degradation caused by Singlet-triplet annihilation and triplet-triplet annihilation (STA and TTA) effects. Since STA and TTA are proportional to exciton concentration. Quenching effects can thus be suppressed by reducing the transient exciton concentration, on the basis of which the emission is carried out via two channels, i.e.S in the course of electroluminescence₁And T₁All states can be in radiative transition, and the mode can realize more efficient and reasonable exciton distribution and improve the performance of the device. In view of T₁The excitons in the initial state are in the majority, and the double-emitting electroluminescent dye must be cycled by reasonably controlled interstitial and anti-interstitial transitions to achieve S in the true sense₁Exciton in state and T₁Optimal distribution of the excitons in the states, and thus the balance and coordination of TADF and PH emission, remains a great challenge in how to construct a truly bi-radiative electroluminescent material.

As is known, most of copper complexes are exothermic to excite delayed fluorescence or phosphorescent, and few copper complexes have the characteristics of both thermal excitation delayed fluorescence and phosphorescence dual emission, mainly because the spin-orbit coupling between copper ions and ligands in the copper complexes is weak, so that effective phosphorescence emission is difficult to obtain, but at present, a dual-emission electroluminescent dye is not developed in the copper complexes, so that a very good platform is provided. The work not only embodies the convincing superiority of the dual-emission material in the aspect of exciton utilization rate, but also proves that a feasible way for modulating the emission ratio is feasible, and lays a foundation for the further development and application of the light-emitting material.

Disclosure of Invention

The invention provides a synthesis method and application of a multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye, aiming at solving the technical problem of poor device performance and stability caused by quenching effect caused by exciton accumulation of phosphorescent and thermally-excited delayed fluorescent dyes at present.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is formed by taking DPPPPO, DPNAPO or DPAPO as a ligand and coordinating with CuX, and the molecular structural formula is as follows:

wherein X is Cl, Br or I.

The synthesis method of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is characterized by comprising the following steps:

mixing 1mmol of polydentate phosphine ligand, 0.5-1 mmol of CuX and 5-10 ml of DCM, reacting at 40 ℃ for 1 hour, and then carrying out spin drying to obtain DPPPPCuX, DPNAPCuX or DPAPCuX;

dissolving the obtained 1mmol of DPPPPCuX, DPNAPCuX or DPAPCuX in DCM (dichloromethane), and respectively adding 5-10 mmol of H under ice water bath₂O₂After reacting for 5 hours, extracting with sodium bisulfite, taking the lower layer, drying with anhydrous sodium sulfate, spin-drying, and purifying by column chromatography with a mixture of Ethyl Acetate (EA) and ethanol (EtOH) as eluent to obtain a multidentate phosphine-coordinated copper complex;

in the first step, the multidentate phosphine ligand is DPPPP, DPNAP or DPAP, wherein X is Cl, Br or I. The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is used as a guest material of a light-emitting layer for preparing an electroluminescent device. The multidentate phosphine-coordinated copper complex dual-emission electroluminescenceThe dye has the characteristic of dual emission, can emit thermal excitation delayed fluorescence and phosphorescence, can simultaneously utilize singlet excitons and triplet excitons as the singlet states and the triplet states of the dye can be simultaneously transited, and can realize dynamic distribution of the excitons in the electroluminescent process, thereby realizing the purposes of reducing the accumulation of the excitons to the maximum extent, improving the efficiency of the device, inhibiting the efficiency roll-off of the device and realizing the maximum utilization in the electroluminescent process. In the invention, the multidentate coordination is utilized to increase the spin-orbit coupling of the ligand to the metal, and the halogen is utilized to adjust the charge transfer from the halogen to the ligand, so that the phosphorescence emission of the copper complex is enhanced, and finally, the dual-emission performance of both thermally-excited delayed fluorescence and phosphorescence is obtained. Meanwhile, the conjugation degree of the ligand is increased by adding the benzene ring, so that the luminescent color of the copper complex is adjusted. The multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye electroluminescent material prepared by the invention can realize a high-efficiency electroluminescent device driven by ultra-low voltage, and the current efficiency of the electroluminescent device reaches the maximum value of 24.7 cd.A^-1The external quantum efficiency reached a maximum of 19.3%.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye used for the electroluminescent guest material of the electroluminescent device has the following advantages:

1. can be used as a guest for a light-emitting layer of an electroluminescent device.

2. The performance of the electroluminescent device material is improved, the material has good thermodynamic stability, the cracking temperature is 389-419 ℃, and the material has the characteristic of double emission. The invention improves the luminous efficiency and brightness of the organic electroluminescent material, and is mainly applied to organic electroluminescent diode devices.

Drawings

FIG. 1 is a graph showing UV fluorescence spectra of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye, a graph showing fluorescence spectra and a graph showing phosphorescence spectra of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye dissolved in a dichloromethane solvent in experiment one, experiment two and experiment three, ■ ● A being a graph showing UV spectra of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye dissolved in a dichloromethane solvent in experiment one, experiment two and experiment three, respectively, □ A being a graph showing fluorescence spectra of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye dissolved in a dichloromethane solvent in experiment one, experiment two and experiment three, respectively, and;

FIG. 2 is a thermogravimetric analysis chart showing the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dyes in experiment one, experiment two and experiment three, ■. tanglesolidup-solidup respectively shows the thermogravimetric analysis chart of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dyes in experiment one, experiment two and experiment three;

FIG. 3 is a chart showing UV fluorescence spectra, fluorescence spectra and phosphorescence spectra of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes dissolved in dichloromethane solvent in experiment four, experiment five and experiment six, ■ ● A represents the UV spectra of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, respectively, □ A represents the fluorescence spectra of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes dissolved in dichloromethane solvent in experiment four, experiment five and experiment six, respectively, and Zhi represents the phosphorescence spectra of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, respectively;

FIG. 4 is a thermogravimetric analysis chart showing multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, wherein ■. tanglesolidup-solidup-a-solidup respectively shows the thermogravimetric analysis chart of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six;

FIG. 5 is a graph showing ultraviolet fluorescence spectra, fluorescence spectra and phosphorescence spectra of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye dissolved in a methylene chloride solvent in experiment seven, experiment eight and experiment nine, ■ ● A indicates the ultraviolet spectra of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye dissolved in the methylene chloride solvent in experiment seven, experiment eight and experiment nine, respectively, □ A indicates the fluorescence spectra of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye dissolved in the methylene chloride solvent in experiment seven, experiment eight and experiment nine, respectively, and Z indicates the phosphorescence spectra of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment seven, experiment eight and experiment nine;

FIG. 6 is a thermogravimetric analysis chart showing multidentate phosphine-coordinated copper complex dual-emission electroluminescent dyes in experiment seven, experiment eight and experiment nine, and ■. tanglesolidup-solidup respectively shows the thermogravimetric analysis chart of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dyes in experiment seven, experiment eight and experiment nine;

FIG. 7 is a voltage-current density relationship curve of the electroluminescent device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in the first experiment, the second experiment and the third experiment, wherein ■ ● A in the graph represents the voltage-current density relationship curve of the electroluminescent device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in the first experiment, the second experiment and the third experiment respectively;

FIG. 8 is a voltage-luminance relationship curve of an electroluminescent device of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment one, experiment two and experiment three, wherein ■ ● A in the graph represents the voltage-luminance relationship curve of the electroluminescent device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment one, experiment two and experiment three respectively;

FIG. 9 is a luminance-current efficiency relationship curve of the electroluminescent device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in the first experiment, the second experiment and the third experiment, wherein ■ ● A in the diagram represents the luminance-current efficiency relationship curve of the electroluminescent device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in the first experiment, the second experiment and the third experiment respectively;

FIG. 10 is a luminance-power efficiency relationship curve of an electroluminescent device of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment one, experiment two and experiment three, wherein ■ ● A in the diagram represents the luminance-power efficiency relationship curve of the electroluminescent device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment one, experiment two and experiment three, respectively;

FIG. 11 is the current density-external quantum efficiency curve efficiency of the electroluminescent device of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment one, experiment two and experiment three, wherein ■ ● A in the graph represents the current density-external quantum efficiency curve efficiency of the electroluminescent device of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment one, experiment two and experiment three respectively;

FIG. 12 is an electroluminescence spectrum of an electroluminescence device of multidentate phosphine-coordinated copper complex dual-emission electroluminescent dyes in experiment one, experiment two and experiment three, wherein ■ ● A in the diagram represents the electroluminescence spectrum of the electroluminescence device of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dyes in experiment one, experiment two and experiment three respectively;

FIG. 13 is a graph showing the voltage-current density relationship curves of the electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, wherein ■ ● A in the graph indicates the voltage-current density relationship curves of the electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, respectively;

FIG. 14 is a graph showing the voltage-luminance relationship between the electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, wherein ■ ● A in the graph indicates the voltage-luminance relationship between the electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, respectively;

FIG. 15 is a graph showing the relationship between luminance and current efficiency of electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, wherein ■ ● A in the graph represents the relationship between luminance and current efficiency of electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, respectively;

FIG. 16 is a graph showing the relationship between luminance and power efficiency of electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, wherein ■ ● A in the graph represents the relationship between luminance and power efficiency of electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, respectively;

FIG. 17 is the current density-external quantum efficiency curve efficiencies of the electroluminescent devices of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, wherein ■ ● A in the graph represents the current density-external quantum efficiency curve efficiencies of the electroluminescent devices of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, respectively;

FIG. 18 is an electroluminescence spectrum of an electroluminescence device of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six, wherein ■ ● A in the graph represents the electroluminescence spectrum of the electroluminescence device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in experiment four, experiment five and experiment six respectively;

FIG. 19 is a graph showing the voltage-current density relationship of the electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in the seventh, eighth and ninth experiments, wherein ■ ● A-solidup in the graph indicates the voltage-current density relationship of the electroluminescent devices using multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in the seventh, eighth and ninth experiments, respectively;

FIG. 20 is a graph showing the voltage-luminance relationship between the electroluminescent devices using the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in the seventh, eighth and ninth experiments, wherein ■ ● A-solidup in the graph indicates the voltage-luminance relationship between the electroluminescent devices using the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in the seventh, eighth and ninth experiments, respectively;

FIG. 21 is a graph showing the relationship between luminance and current efficiency of an electroluminescent device using a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment seven, experiment eight or experiment nine, wherein ■ ● A in the graph represents the relationship between luminance and current efficiency of an electroluminescent device using a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment seven, experiment eight or experiment nine, respectively;

FIG. 22 is a luminance-power efficiency relationship curve of an electroluminescent device of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment seven, experiment eight and experiment nine, wherein ■ ● A in the diagram represents the luminance-power efficiency relationship curve of the electroluminescent device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment seven, experiment eight and experiment nine, respectively;

FIG. 23 is the current density-external quantum efficiency curve efficiencies of electroluminescent devices of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in the seventh, eighth and ninth experiments, wherein ■ ● A in the graph represents the current density-external quantum efficiency curve efficiencies of electroluminescent devices of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes in the seventh, eighth and ninth experiments respectively;

FIG. 24 is an electroluminescence spectrum of an electroluminescence device of multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment seven, experiment eight and experiment nine, wherein ■ ● A in the graph represents the electroluminescence spectrum of the electroluminescence device of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment seven, experiment eight and experiment nine, respectively;

FIGS. 25 to 33 are graphs of the temperature-variable lifetime of 80K to 300K for the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dyes from experiment one to experiment nine, and it can be seen from each graph that: the lifetime is sharply decreased with increasing temperature, phosphorescent emission at low temperature, and thermal excitation delayed fluorescence property is exhibited with increasing temperature, thereby exhibiting dual emission.

Detailed Description

The technical solution of the present invention is not limited to the following specific embodiments, but includes any combination of the specific embodiments.

The first embodiment is as follows: the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is formed by coordinating DPPPPO, DPNAPO or DPAPO serving as a ligand with CuX, and has a molecular structural formula as follows:

wherein X is Cl, Br or I.

The second embodiment is as follows: the synthesis method of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye comprises the following steps:

dissolving the obtained 1mmol of DPPPPCuX, DPNAPCuX or DPAPCuX in DCM, and respectively adding 5-10 mmol of H under ice water bath₂O₂After reacting for 5 hours, extracting with sodium bisulfite, taking the lower layer, drying with anhydrous sodium sulfate, spin-drying, and purifying by column chromatography with a mixture of ethyl acetate and ethanol as eluent to obtain a multidentate phosphine-coordinated copper complex;

in the first step, the multidentate phosphine ligand is DPPPP, DPNAP or DPAP, wherein X is Cl, Br or I.

The third concrete implementation mode: the present embodiment is different from the second embodiment in that the mass ratio of the multidentate phosphine ligand to CuX is (1-2) to 1. The rest is the same as the second embodiment.

The fourth concrete implementation mode: the present embodiment is different from the second embodiment in that the ratio of the multidentate phosphine ligand to CuX is 1: 1. The rest is the same as the second embodiment.

The fifth concrete implementation mode: the difference between the second embodiment and the second embodiment is that the volume ratio of EA to EtOH in the mixture of ethyl acetate and ethanol is 1: 10. The rest is the same as the second embodiment.

The sixth specific implementation mode: the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is used as a guest material of a light-emitting layer to prepare an electroluminescent device.

The following experiments are adopted to verify the effect of the invention:

experiment one: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

mixing 1mmol of polydentate phosphine ligand, 1mmol of CuCl and 5ml of DCM, reacting at 40-45 ℃ for 10-15 hours, and spin-drying to obtain the DPPPPCuCl.

The resulting 1mmol of DPPPCuCl was dissolved in DCM and 10mmol of H was added under ice-water bath₂O₂And after reacting for 5 hours, extracting with sodium bisulfite, taking the lower layer, drying with anhydrous sodium sulfate, spin-drying, and purifying by column chromatography with EA and EtOH as eluent to obtain the multidentate phosphine-coordinated copper complex.

Wherein the amount ratio of the multidentate phosphine ligand to CuCl is 1: 1.

The DPPPPCuCl and H₂O₂The quantity ratio is 1: 2.

The volume ratio of EA to EtOH in the mixed solvent of EA and EtOH is 1: 10.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment has the structural formula

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPPPPOCuCl.

The nuclear magnetic resonance spectrometer is adopted to detect the multifunctional modified DPPPPPOCuCl prepared by the test, and the detection result is as follows:

¹H NMR(TMS,CDCl₃,400MHz):＝7.984(s,4H),7.648(s,4H),7.458-7.402(t,J＝6.4Hz,7H),7.313-7.011(m,25H),6.900(t,J＝8Hz,1H),6.659(s,4H),6.440ppm(s,1H)；LDI-TOF:m/z(％):1046(100)[M⁺]；elemental analysis(％)for C₅₆H₄₆CuClOP₄:C,64.26；H,4.43；

the experiment obtains the ultraviolet fluorescence spectrum of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPPPPPOCuCl, and the phosphorescence spectrum is shown in figure 1. The thermogravimetric analysis spectrogram of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuCl obtained by the experiment is shown in figure 2, and the graph shows that the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuCl is 399 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuCl as a luminescent layer comprises the following steps:

firstly, cleaning the plastic substrate by deionized waterPutting into a vacuum evaporator with vacuum degree of 1 × 10^-6mbar, evaporation rate set at 0.1nm s^-1An anode conducting layer with the thickness of 10nm is formed on a glass or plastic substrate by vapor deposition of Indium Tin Oxide (ITO);

secondly, evaporating a hole injection layer material MoOx on the anode conducting layer to obtain a 10 nm-thick hole injection layer;

thirdly, evaporating a hole transport layer material TAPC on the hole injection layer to obtain a hole transport layer with the thickness of 40 nm;

fourthly, evaporating and plating a bidentate phosphine coordination copper complex dual-emission electroluminescent dye on the hole transport layer to be mixed with a main material mCP to obtain a mixture with the thickness of 15 nm;

fifthly, evaporating and plating an electron transport layer material TPBi on the light-emitting layer, wherein the thickness of the electron transport layer material TPBi is 80 nm;

sixthly, evaporating and plating an electron injection layer material LiF on the electron transport layer, wherein the thickness of the electron injection layer is 10 nm;

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows: ITO/MoOx (10nm)/TAPC (40nm)/mCP DPPPOCuCl (15nm)/TPBi (80nm)/LiF (10 nm)/Al. In the experiment, the voltage-current density relation curve of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuCl is shown in FIG. 7, and therefore, the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuCl material has semiconductor characteristics and the threshold voltage is 3.7V. The voltage-brightness relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuCl in the experiment is shown in FIG. 8, and the figure shows that the starting voltage of the device is 3.7V. The graph of the relationship between luminance and current efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuCl in the experiment is shown in FIG. 9, and the graph shows that the device has the luminance of 2.4 cd.m^-2When the current efficiency reaches the maximum value of 24.7 cd.A^-1. The luminance-power efficiency of an electroluminescent device prepared by using multidentate phosphine coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuCl is shown in the experimentThe graph of the rate dependence is shown in FIG. 10, from which it can be seen that the luminance of the device is 2.1cd · m^-2When the power efficiency reaches the maximum value of 27.1 lm.W^-1. The current density-external quantum efficiency relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuCl in the experiment is shown in figure 11, and the graph shows that the device has the brightness of 0.4 mA-cm^-2Then, a maximum external quantum efficiency of 19.3% was obtained. The electroluminescence spectrum of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuCl in the experiment is shown in figure 12, and the electroluminescence peak of the device is shown in the figure at 581 nm. Fig. 25 is a graph of the 80K-300K temperature-variable lifetime of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in the first experiment, and it can be seen from the graph that the lifetime is sharply decreased with the increase of temperature, phosphorescence emission is performed at low temperature, and thermal excitation delayed fluorescence is exhibited with the increase of temperature, thereby embodying dual emission.

Experiment two: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

mixing 1mmol of polydentate phosphine ligand, 1mmol of CuBr and 5ml of DCM, reacting at 40-45 ℃ for 10-15 hours, and spin-drying to obtain the DPPPPCuBr.

The resulting 1mmol of DPPPPuBr was dissolved in DCM and 10mmol of H were added under ice-water bath₂O₂And after reacting for 5 hours, extracting with sodium bisulfite, taking the lower layer, drying with anhydrous sodium sulfate, spin-drying, and purifying by column chromatography with EA and EtOH as eluent to obtain the multidentate phosphine-coordinated copper complex.

Wherein the quantity ratio of the multidentate phosphine ligand to CuBr is 1: 1.

The DPPPPCuBr and H₂O₂The quantity ratio is 1: 2.

The volume ratio of EA to EtOH in the mixed solvent of EA and EtOH is 1: 10.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPPPPOCuBr.

The nuclear magnetic resonance spectrometer is adopted to detect the multifunctional modified DPPPPPOCuBr prepared in the test, and the detection result is as follows:

¹H NMR(TMS,CDCl₃,400MHz):＝7.998(s,4H),7.587(s,4H),7.453(t,J＝6.4Hz,3H),7.378(s,5H),7.310(d,J＝7.2Hz,7H),7.188(t,J＝7.6Hz,8H),7.126(s,4H),7.026(t,J＝7.2Hz,5H),6.948(t,J＝7.6Hz,1H),6.672(s,4H),6.552ppm(s,1H)；LDI-TOF:m/z(％):1002(100)[M⁺]；elemental analysis(％)for C₅₆H₄₆CuBrOP₄:C,67.10；H,4.63；

the experiment obtains the ultraviolet fluorescence spectrum of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPPPPOCuBr, and the phosphorescence spectrum is shown in figure 1. The thermogravimetric analysis spectrogram of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuBr obtained in the experiment is shown in figure 2, and the graph shows that the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuBr is 396 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPPPPOCuBr as the luminescent layer comprises the following steps:

firstly, putting the plastic substrate cleaned by deionized water into a vacuum evaporation plating instrument with the vacuum degree of 1 multiplied by 10^-6mbar, evaporation rate set at 0.1nm s^-1An anode conducting layer with the thickness of 10nm is formed on a glass or plastic substrate by vapor deposition of Indium Tin Oxide (ITO);

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows: ITO/MoOx (10nm)/TAPC (40nm)/mCP DPPPOCuBr (15nm)/TPBi (80nm)/LiF (10 nm)/Al. In the experiment, the voltage-current density relation curve of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuBr is shown in fig. 7, and the graph shows that the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuBr material has semiconductor characteristics and the threshold voltage of the material is 3.7V. In the experiment, the voltage-brightness relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuBr is shown in figure 8, and the figure shows that the starting voltage of the device is 3.9V. The graph of the relationship between luminance and current efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuBr in the experiment is shown in FIG. 9, and the graph shows that the luminance of the device is 2.6 cd.m^-2When the current efficiency reaches the maximum value of 24.3 cd.A^-1. The graph of the relationship between luminance and power efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuBr in the experiment is shown in FIG. 10, and the graph shows that the luminance of the device is 5.2 cd.m^-2When the power efficiency reaches the maximum value of 22.5 lm.W^-1. The current density-external quantum efficiency relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPPPPOCuBr in the experiment is shown in figure 11, and the graph shows that the device has the brightness of 0.7 mA-cm^-2Then, a maximum external quantum efficiency of 17.5% was obtained. The electroluminescence spectrum of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuBr in the experiment is shown in figure 12, and the electroluminescence peak of the device is shown in the figure at 581 nm. FIG. 26 shows multidentate phosphine coordination in experiment twoAn 80K-300K temperature-variable lifetime spectrogram of the copper complex dual-emission electroluminescent dye shows that the lifetime is sharply reduced along with the temperature rise, phosphorescence emission is realized at low temperature, and thermal excitation delayed fluorescence is realized along with the temperature rise, so that dual emission is realized.

Experiment three: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

mixing 1mmol of polydentate phosphine ligand, 1mmol of CuI and 5ml of DCM, reacting at 40-45 ℃ for 10-15 hours, and spin-drying to obtain the DPPPPCuI.

The resulting 1mmol of DPPPPPCuI was dissolved in DCM and 10mmol of H was added under ice-water bath₂O₂And after reacting for 5 hours, extracting with sodium bisulfite, taking the lower layer, drying with anhydrous sodium sulfate, spin-drying, and purifying by column chromatography with EA and EtOH as eluent to obtain the multidentate phosphine-coordinated copper complex.

Wherein the amount ratio of the multidentate phosphine ligand to CuI is 1: 1.

The DPPPPCuI and H₂O₂The quantity ratio is 1: 2.

The volume ratio of EA to EtOH in the mixed solvent of EA and EtOH is 1: 10.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPPPPOCuI.

The nuclear magnetic resonance spectrometer is adopted to detect the multifunctional modified DPPPPPOCuI prepared by the test, and the detection result is as follows:

¹H NMR(TMS,CDCl₃,400MHz):＝7.974(s,4H),7.518(s,5H),7.429(t,J＝7.2Hz,4H),7.330-7.172(m,16H),7.115(s,5H),7.039(d,J＝6.8Hz,6H),6.927(s,1H),6.707ppm(s,5H)；LDI-TOF:m/z(％):1049(100)[M⁺]；elemental analysis(％)for C₅₆H₄₆CuIOP₄:C,64.10；H,4.42；

the experiment obtains the ultraviolet fluorescence spectrum of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPPPPPOCuI, and the phosphorescence spectrum is shown in figure 1.

The thermogravimetric analysis spectrogram of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuI obtained by the experiment is shown in figure 2, and the graph shows that the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuI is 419 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuI as a luminescent layer comprises the following steps:

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows: ITO/MoOx (10nm)/TAPC (40nm)/mCP DPPPOCuI (15nm)/TPBi (80nm)/LiF (10 nm)/Al. The voltage-current density relationship curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuI in the experiment is shown in figure 7, and the voltage-current density relationship curve can be obtained from the graphThe multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPPPPPOCuI material has semiconductor characteristics, and the threshold voltage of the material is 4.2V. The voltage-brightness relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuI in the experiment is shown in FIG. 8, and the figure shows that the starting voltage of the device is 4V. The graph of the relationship between luminance and current efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuI in the experiment is shown in FIG. 9, and the graph shows that the device has the luminance of 2.4 cd.m^-2When the current efficiency reaches the maximum value of 6.5 cd.A^-1. The graph of the relationship between luminance and power efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuI in the experiment is shown in FIG. 10, and the graph shows that the device has the luminance of 6.1 cd.m^-2When the power efficiency reaches the maximum value of 5.2 lm.W^-1. The current density-external quantum efficiency relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPOCuI in the experiment is shown in figure 11, and the graph shows that the device has the brightness of 0.55 mA-cm^-2Then, the maximum external quantum efficiency of 3.5% was obtained. The electroluminescence spectrum of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPPPPPOCuI in the experiment is shown in FIG. 12, and the electroluminescence peak of the device is at 573 nm. FIG. 27 is a graph of the 80K-300K temperature-variable lifetime of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment III, from which it can be seen that the lifetime is sharply reduced with the increase of temperature, phosphorescence emission is performed at low temperature, and thermal excitation delayed fluorescence is exhibited with the increase of temperature, thereby embodying dual emission.

Experiment four: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

mixing 1mmol of polydentate phosphine ligand, 1mmol of CuCl and 5ml of DCM, reacting at 40 ℃ for 10-15 hours, spin-drying, and purifying by taking DCM and PE as eluent column chromatography to obtain a polydentate phosphine coordination copper complex;

wherein the amount ratio of the multidentate phosphine ligand to CuCl is 1: 1.

The volume ratio of DCM to PE in the mixed solvent of DCM and PE is 1: 20.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPNAPOCuCl.

The multifunctional modified DPNAPOCCl prepared by the test is detected by a nuclear magnetic resonance spectrometer, and the detection result is as follows:

m/z:553.10(100.0％),553.60(73.5％),554.10(44.6％),554.60(32.8％),554.10(32.0％),554.10(26.6％),554.60(23.5％),555.10(14.2％),555.10(11.9％),555.60(10.5％),555.10(8.5％),554.60(5.5％),556.10(3.8％),555.60(2.8％),555.60(2.0％),555.10(1.1％)。

Elemental Analysis(％)for C₆₈H₅₂CuClOP₄:C,73.71；H,4.73；O,1.44。

the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuCl obtained by the experiment is 393 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex double-emitting electroluminescent dye DPNAPOCuCl as a light-emitting layer is as follows:

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows: ITO/MoOx (10nm)/TAPC (40nm)/mCP DPNAPOCCl (15nm)/TPBi (80nm)/LiF (10 nm)/Al. In this experiment, the voltage-current density relationship curve of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuCl is shown in fig. 13, and it can be known from the graph that the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuCl material has semiconductor characteristics and the threshold voltage thereof is 4V. The voltage-brightness relationship curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuCl in the experiment is shown in FIG. 14, and the figure shows that the starting voltage of the device is 4V. The graph of the relationship between luminance and current efficiency of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex double-emitting electroluminescent dye DPNAPOCuCl in the experiment is shown in FIG. 15, and the graph shows that the device has the luminance of 2.4 cd.m^-2When the current efficiency reaches the maximum value of 13.2 cd.A^-1. The graph of the relationship between luminance and power efficiency of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuCl in the experiment is shown in FIG. 16, and the graph shows that the device has luminance of 2.1 cd.m^-2When the power efficiency reaches the maximum value of 7.6 lm.W^-1. The current density-external quantum efficiency relationship curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuCl in the experiment is shown in FIG. 17, and the graph shows that the device has the brightness of 6mA cm^-2Then, a maximum external quantum efficiency of 5.3% was obtained. The electroluminescence spectrum of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCCl in the experiment is shown in FIG. 18The electroluminescent peak of the device is at 589 nm. FIG. 28 is a graph of the 80K-300K temperature-variable lifetime of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment IV, from which it can be seen that the lifetime is sharply reduced with the increase of temperature, phosphorescence emission is performed at low temperature, and thermal excitation delayed fluorescence is exhibited with the increase of temperature, thereby embodying dual emission.

Experiment five: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

mixing 1mmol of polydentate phosphine ligand, 1mmol of CuBr and 5ml of DCM, reacting at 40-45 ℃ for 10-15 hours, spin-drying, and performing column chromatography purification by taking DCM and PE as eluent to obtain a polydentate phosphine coordination copper complex;

The volume ratio of DCM to PE in the mixed solvent of DCM and PE is 1: 20.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPNAPOCuBr.

The multifunctional modified DPNAPOCuBr prepared in the test is detected by mass spectrum, and the detection result is as follows:

m/z:575.07(100.0％),576.07(97.3％),575.57(73.5％),576.57(71.5％),576.07(44.6％),577.07(43.4％),576.57(32.8％),577.57(31.9％),577.08(25.9％),576.08(21.6％),577.08(11.9％),578.07(11.6％),576.58(6.3％),577.58(5.8％),576.08(5.1％),578.58(2.7％),577.58(1.9％),578.08(1.1％)。Elemental Analysis(％)for C₆₈H₅₂CuBrOP₄:C,70.87；H,4.55；O,1.39。

the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuBr obtained by the experiment is 394 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex double-emitting electroluminescent dye DPNAPOCuBr as a light-emitting layer is as follows:

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows: ITO/MoOx (10nm)/TAPC (40nm)/mCP PPPNADPCuBr (15nm)/TPBi (80nm)/LiF (10 nm)/Al. In the experiment, the voltage-current density relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuBr is shown in figure 13, so that the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuBr material has semiconductor characteristics and the threshold voltage is 4V. The voltage-brightness relationship curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuBr in the experiment is shown in FIG. 14, and the figure shows that the starting voltage of the device is 4V. The graph of the relationship between luminance and current efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuBr in the experiment is shown in FIG. 15This figure shows that the device has a luminance of 2.6cd · m^-2When the current efficiency reaches the maximum value of 11.8 cd.A^-1. The graph of the relationship between luminance and power efficiency of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuBr in the experiment is shown in FIG. 16, and it can be seen from the graph that the luminance of the device is 2.1 cd.m^-2When the power efficiency reaches the maximum value of 7.8 lm.W^-1. The current density-external quantum efficiency relationship curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuBr in the experiment is shown in FIG. 17, and the graph shows that the device has the brightness of 6mA cm^-2Then, the maximum external quantum efficiency of 4.2% was obtained. The electroluminescence spectrum of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuBr in the experiment is shown in FIG. 18, and the electroluminescent peak of the device is at 600 nm. FIG. 29 is a graph of the 80K-300K temperature-variable lifetime of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment five, and it can be seen from the graph that the lifetime is sharply reduced along with the temperature increase, phosphorescence emission is performed at low temperature, and thermal excitation delayed fluorescence is displayed along with the temperature increase, so that dual emission is realized.

Experiment six: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

mixing 1mmol of polydentate phosphine ligand, 1mmol of CuI and 5ml of DCM, reacting at 40-45 ℃ for 10-15 hours, spin-drying, and performing column chromatography purification by taking DCM and PE as eluent to obtain a polydentate phosphine coordination copper complex;

wherein the amount ratio of the multidentate phosphine ligand to CuI is 1: 1.

The volume ratio of DCM to PE in the mixed solvent of DCM and PE is 1: 20.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPNAPOCuI.

The multifunctional modified DPNAPOCI prepared by the test is detected by mass spectrum, and the detection result is as follows:

m/z:599.07(100.0％),599.57(73.5％),600.07(44.6％),600.57(32.8％),600.07(26.6％),601.07(11.9％),600.57(5.5％),601.57(2.8％),601.07(1.1％)。Elemental Analysis(％)for C₆₈H₅₂CuIOP₄:C,68.09；H,4.37；O,1.33。

the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuI obtained by the experiment is 399 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex double-emitting electroluminescent dye DPNAPOCI as a light-emitting layer comprises the following steps:

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows: ITO/MoOx (10nm)/TAPC (40nm)/mCP DPNAPOCI (15nm)/TPBi (80nm)/LiF (10 nm)/Al.In this experiment, the voltage-current density relationship curve of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuI is shown in fig. 13, and it can be known from the graph that the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCuI material has semiconductor characteristics and the threshold voltage thereof is 4V. The voltage-brightness relationship curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCI in the experiment is shown in FIG. 14, and the figure shows that the starting voltage of the device is 4V. FIG. 15 shows the luminance-current efficiency relationship curve of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCI in this experiment, and it can be seen from the graph that the luminance of the device is 2.4 cd.m^-2When the current efficiency reaches the maximum value of 7.5 cd.A^-1. The graph of the relationship between luminance and power efficiency of the electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCI in this experiment is shown in FIG. 16, and it can be seen from the graph that the device has a luminance of 2.1 cd.m^-2When the power efficiency reaches the maximum value of 7.2 lm.W^-1. The current density-external quantum efficiency relationship curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCI in the experiment is shown in FIG. 17, and the graph shows that the device has the brightness of 6mA cm^-2Then, the maximum external quantum efficiency of 4.8% was obtained. The electroluminescence spectrum of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPNAPOCI in the experiment is shown in FIG. 18, and the electroluminescent peak of the device is 605 nm. FIG. 30 is a graph of the 80K-300K temperature-variable lifetime of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment six, and it can be seen from the graph that the lifetime is sharply reduced with the increase of temperature, phosphorescence emission is performed at low temperature, and thermal excitation delayed fluorescence is exhibited with the increase of temperature, thereby embodying dual emission.

Experiment seven: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

wherein the amount ratio of the multidentate phosphine ligand to CuCl is 1: 1.

The volume ratio of DCM to PE in the mixed solvent of DCM and PE is 1: 20.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPAPOCuCl.

The mass spectrum is adopted to detect the multifunctional modified DPAPOCuCl prepared by the test, and the detection result is as follows:

m/z:628.12(100.0％),628.62(86.5％),629.12(44.6％),629.62(38.6％),629.13(37.0％),629.12(32.0％),629.62(27.7％),630.12(16.5％),630.12(14.2％),630.62(12.3％),630.12(11.8％),629.63(10.4％),631.12(5.3％),630.63(4.6％),630.63(3.1％),630.13(1.8％),631.62 (1.4％)；Elemental Analysis(％)for C₈₀H₅₈CuClOP₄:C,76.37；H,4.65；O,1.27。

the experiment obtains the ultraviolet fluorescence spectrum of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPAPOCuCl, and the phosphorescence spectrum is shown in figure 5. The thermogravimetric analysis spectrogram of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuCl obtained by the experiment is shown in figure 6, and the graph shows that the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuCl is 388 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuCl as a luminescent layer comprises the following steps:

firstly, putting the plastic substrate cleaned by deionized water into a vacuum evaporation plating instrument with the vacuum degree of 1 multiplied by 10^-6mbar, evaporation rate set at 0.1nm s^-1The evaporation material on the glass or plastic substrate is Indium Tin Oxide (ITO) with the thickness of 1An anode conductive layer of 0 nm;

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows: ITO/MoOx (10nm)/TAPC (40nm)/mCP DPAPOCuCl (15nm)/TPBi (80nm)/LiF (10 nm)/Al. In the experiment, a voltage-current density relation curve of an electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuCl is shown in fig. 19, and therefore, the graph shows that the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuCl material has semiconductor characteristics, and the threshold voltage of the material is 3.9V. The voltage-brightness relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPCuCl in the experiment is shown in figure 20, and the figure shows that the starting voltage of the device is 4V. The graph of the relationship between luminance and current efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuCl in the experiment is shown in FIG. 21, and the graph shows that the device has the luminance of 2.4 cd.m^-2When the current efficiency reaches the maximum value of 14.7 cd.A^-1. The graph of the relationship between luminance and power efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuCl in the experiment is shown in FIG. 22, and the graph shows that the device has the luminance of 2.1 cd.m^-2When the power efficiency reaches the maximum value of 7.5 lm.W^-1. The experiment uses multidentate phosphine to coordinate copperThe current density-external quantum efficiency curve of the electroluminescent device prepared from the compound dual-emitting electroluminescent dye DPAPOCuCl is shown in FIG. 23, and the graph shows that the device has the brightness of 6mA cm^-2Then, the maximum external quantum efficiency of 15.3% was obtained. The electroluminescence spectrum of an electroluminescence device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescence dye DPAPOCuCl in the experiment is shown in figure 24, and the electroluminescence peak of the device is at 624 nm. FIG. 31 is a graph of the 80K-300K temperature-variable lifetime of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment seven, and it can be seen from the graph that the lifetime is sharply reduced with the increase of temperature, phosphorescence emission is performed at low temperature, and thermal excitation delayed fluorescence is displayed with the increase of temperature, so that dual emission is reflected.

Experiment eight: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

The volume ratio of DCM to PE in the mixed solvent of DCM and PE is 1: 20.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPAPOCuBr.

The mass spectrum is adopted to detect the multifunctional modified DPAPOCuBr prepared by the test, and the detection result is as follows:

m/z:650.10(100.0％),651.10(97.3％),650.60(85.4％),651.60(84.2％),651.10(44.6％),652.09(43.4％),651.60(38.1％),652.60(37.5％),652.10(15.0％),651.10(30.0％),653.10(15.6％),652.10(13.4％),651.60(10.4％),652.60(9.0％),651.10(6.9％),652.60(4.6％),653.60(4.0％),652.10(3.1％),652.10(2.2％),653.10(2.1％),650.60(1.1％),652.60(1.1％)

Elemental Analysis(％)for C₈₀H₅₈CuBrOP₄:C,73.76；H,4.49；O,1.23。

the experiment obtains the ultraviolet fluorescence spectrum of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPAPOCuBr, and the phosphorescence spectrum is shown in figure 5. The thermogravimetric analysis spectrogram of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr obtained in the experiment is shown in fig. 6, and the graph shows that the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr is 389 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPAPOCuBr as the light-emitting layer comprises the following steps:

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows:ITO/MoOx (10nm)/TAPC (40nm)/mCP DPAPOCuBr (15nm)/TPBi (80nm)/LiF (10 nm)/Al. In the experiment, a voltage-current density relation curve of an electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr is shown in fig. 19, and therefore, the graph shows that the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr material has semiconductor characteristics, and the threshold voltage of the material is 3.8V. The voltage-brightness relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr in the experiment is shown in figure 20, and the figure shows that the starting voltage of the device is 3.9V. The graph of the relationship between luminance and current efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr in the experiment is shown in FIG. 21, and the graph shows that the luminance of the device is 2.6 cd.m^-2When the current efficiency reaches the maximum value of 16.3 cd.A^-1. The graph of the relationship between brightness and power efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr in the experiment is shown in FIG. 22, and the graph shows that the device has the brightness of 2.1 cd.m^-2When the power efficiency reaches the maximum value of 13.6 lm.W^-1. The current density-external quantum efficiency relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr in the experiment is shown in figure 23, and the graph shows that the device has the brightness of 6 mA-cm^-2Then, a maximum external quantum efficiency of 15.4% was obtained. The electroluminescence spectrum of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuBr in the experiment is shown in figure 24, and the electroluminescence peak of the device is at 623 nm. FIG. 32 is a graph of the 80K-300K temperature-variable lifetime of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment eight, from which it can be seen that the lifetime is sharply reduced with the increase of temperature, phosphorescence emission is performed at low temperature, and thermal excitation delayed fluorescence is exhibited with the increase of temperature, thereby embodying dual emission.

Experiment nine: the synthesis method of the experimental multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is realized according to the following steps:

wherein the amount ratio of the multidentate phosphine ligand to CuI is 1: 1.

The volume ratio of DCM to PE in the mixed solvent of DCM and PE is 1: 20.

The multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye obtained by the experiment is DPAPOCuI.

The mass spectrum is adopted to detect the multifunctional modified DPAPOCuI prepared by the test, and the detection result is as follows:

m/z:674.09(100.0％),674.59(86.5％),675.09(44.6％),675.59(38.6％),675.09(37.0％),676.09(16.5％),675.59(10.4％),676.59(4.6％),676.10(1.8％)。Elemental Analysis(％)for C₈₀H₅₈CuIOP₄:C,71.19；H,4.33；O,1.19。

the experiment obtains the ultraviolet fluorescence spectrum of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye DPAPCuI, and the phosphorescence spectrum is shown in figure 5. The thermogravimetric analysis spectrogram of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuI obtained by the experiment is shown in FIG. 6, and the graph shows that the cracking temperature of the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuI is 407 ℃.

The method for preparing the electroluminescent device by using the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuI as a light-emitting layer comprises the following steps:

and seventhly, evaporating a cathode conducting layer which is made of metal and has the thickness of 10nm on the electron injection layer to obtain the electrophosphorescent device. And seventhly, the metal is aluminum. The structure of the experimental electrophosphorescent device is as follows: ITO/MoOx (10nm)/TAPC (40nm)/mCP DPAPOCuI (15nm)/TPBi (80nm)/LiF (10 nm)/Al. In the experiment, a voltage-current density relation curve of an electroluminescent device prepared from the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuI is shown in fig. 19, and therefore, the graph shows that the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuI material has semiconductor characteristics, and the threshold voltage of the material is 3.9V. The voltage-brightness relation curve of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuI in the experiment is shown in figure 20, and the figure shows that the starting voltage of the device is 3.9V. The graph of the relationship between luminance and current efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuI in the experiment is shown in FIG. 21, and the graph shows that the device has the luminance of 2.4 cd.m^-2When the current efficiency reaches the maximum value of 7.7 cd.A^-1. The graph of the relationship between brightness and power efficiency of the electroluminescent device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye DPAPOCuI in the experiment is shown in FIG. 22, and the graph shows that the device has the brightness of 2.1 cd.m^-2When the power efficiency reaches the maximum value of 4 lm.W^-1. The experiment shows that the electricity prepared by the multidentate phosphine coordinated copper complex dual-emitting electroluminescent dye DPAPOCuIThe current density-external quantum efficiency curve of the electroluminescent device is shown in FIG. 23, from which it can be seen that the device has a luminance of 6mA cm^-2At this time, a maximum external quantum efficiency of 12% was obtained. The electroluminescence spectrum of an electroluminescence device prepared by the multidentate phosphine-coordinated copper complex dual-emitting electroluminescence dye DPAPOCuI in the experiment is shown in figure 24, and the electroluminescence peak of the device is at 624 nm. FIG. 33 is a graph of the 80K-300K temperature-variable lifetime of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye in experiment nine, from which it can be seen that the lifetime is sharply reduced with the increase of temperature, phosphorescence emission is performed at low temperature, and thermal excitation delayed fluorescence is exhibited with the increase of temperature, thereby embodying dual emission.

Claims

1. The application of the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is characterized in that the multidentate phosphine-coordinated copper complex dual-emission electroluminescent dye is used as a guest material of a light-emitting layer for preparing an electroluminescent device, the luminescent dye takes DPAPO as a ligand and is coordinated with CuX, and the molecular structural formula is as follows:

wherein X is Cl or Br,

the synthesis method of the luminescent dye comprises the following steps:

mixing 1mmol of polydentate phosphine ligand, 0.5-1 mmol of CuX and 5-10 ml of DCM, reacting at 40 ℃ for 1 hour, and spin-drying to obtain DPAPCuX; the polydentate phosphine ligand is DPAP, wherein X is Cl or Br, and DCM is dichloromethane;

dissolving the obtained 1mmol of DPAPCuX in DCM, and respectively adding 5-10 mmol of H under ice-water bath₂O₂And after 5 hours of reaction, extracting with sodium bisulfite, taking the lower layer, drying with anhydrous sodium sulfate, spin-drying, and purifying by column chromatography with a mixture of ethyl acetate and ethanol as eluent to obtain the multidentate phosphine-coordinated copper complex.

2. Use of a multidentate phosphine-coordinated copper complex dual-emitting electroluminescent dye according to claim 1, wherein the substance ratio of multidentate phosphine ligand to CuX is 1: 1.

3. The use of a multidentate phosphine-coordinated copper complex dual-emitter electroluminescent dye according to claim 1, wherein the volume ratio of EA to EtOH in the mixture of ethyl acetate and ethanol is 1: 10.