CN117750821A - Organic electroluminescent device and light-emitting panel - Google Patents
Organic electroluminescent device and light-emitting panel Download PDFInfo
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Abstract
The invention discloses an organic electroluminescent device and a luminescent panel, the organic electroluminescent device comprises: a substrate; a first electrode located at one side of the substrate; a light-emitting layer positioned on one side of the first electrode away from the substrate; the second electrode is positioned on one side of the light-emitting layer away from the substrate; a plasmon enhancement layer on a surface of the light emitting layer on a side close to the exciton recombination zone; the plasmon enhancement layer is composed of a main body layer and metal nano particles doped in the main body layer; the plasmon enhancement layer is used for increasing the luminous efficiency of the electroluminescent device by utilizing the plasmon local enhancement effect. According to the technical scheme provided by the invention, the plasmon local enhancement effect is utilized to accelerate the transfer efficiency of excitons, so that the light-emitting efficiency of the device is improved, and meanwhile, the quenching probability of triplet excitons is reduced.
Description
Technical Field
The embodiment of the invention relates to the technical field of luminescence, in particular to an organic electroluminescent device and a luminescent panel.
Background
An Organic Light-Emitting Diode (OLED) can be used for illumination and display technology, and has excellent characteristics of self-luminescence, low power consumption, fast response speed, high luminous efficiency, simple process and the like.
At present, though the internal quantum efficiency of the light-emitting device can reach 100% by using phosphorescent light-emitting materials and optimizing the structure of the light-emitting device, the external quantum efficiency of the light-emitting device actually emitted is 25% due to the dielectric constant difference among the functional layer, the substrate, the air and the like of the light-emitting device; and when the current density of the injection device is increased to improve the light-emitting brightness, the density of triplet excitons is also increased, so that the quenching probability of the triplet excitons is increased, the light-emitting efficiency of the device is reduced, and the service life and the reliability of the device are influenced. Therefore, how to improve the luminous efficiency of the electroluminescent device is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
The embodiment of the invention provides an organic electroluminescent device and a light-emitting panel, which are used for accelerating exciton transfer efficiency by utilizing a plasmon local enhancement effect, improving the light-emitting efficiency of the device and reducing the quenching probability of triplet excitons.
According to an aspect of the present invention, there is provided an organic electroluminescent device comprising:
a substrate;
a first electrode located at one side of the substrate;
a light-emitting layer positioned on one side of the first electrode away from the substrate;
a second electrode located at one side of the light-emitting layer away from the substrate;
a plasmon enhancement layer on a surface of the light emitting layer on a side close to the exciton recombination zone; the plasmon enhancement layer is composed of a main body layer and metal nano particles doped in the main body layer; the plasmon enhancement layer is used for increasing the luminous efficiency of the electroluminescent device by utilizing the plasmon local enhancement effect.
Optionally, the material of the light emitting layer includes a host material for energy transfer and a guest material for light emission; the material of the main body layer is the same as the main body material of the light-emitting layer;
the overlap of the surface plasmon resonance spectrum of the metal nanoparticle with the emission spectrum of the host material is greater than or equal to 20%, and the overlap of the surface plasmon resonance spectrum of the metal nanoparticle with the absorption spectrum of the guest material is greater than or equal to 20%.
Optionally, the metal nanoparticle includes a metal core and a dielectric layer coated on the outer side of the metal core.
Optionally, the thickness of the dielectric layer ranges from 1nm to 30nm.
Optionally, the metal nanoparticle is spherical, ellipsoidal or rod-shaped.
Optionally, the thickness of the main body layer ranges from 5nm to 50nm; the length of the metal nano particles ranges from 1nm to 50nm;
the doping volume ratio of the metal nano particles is in the range of 1-20%.
Optionally, a side of the light emitting layer close to the exciton recombination zone is a side of the light emitting layer close to the first electrode; the plasmon enhancement layer is positioned on the surface of the light-emitting layer, which is close to one side of the first electrode;
or, the side of the light-emitting layer close to the exciton recombination zone is the side of the light-emitting layer close to the second electrode; the plasmon enhancement layer is positioned on the surface of the light-emitting layer, which is close to one side of the second electrode.
Optionally, the organic electroluminescent device further includes:
a first functional layer located between the first electrode and the light emitting layer;
a second functional layer located between the second electrode and the light emitting layer;
wherein when the plasmon enhancement layer is positioned on the surface of the light emitting layer on the side close to the first electrode, the first functional layer is in contact with the surface of the plasmon enhancement layer on the side close to the first electrode; when the plasmon enhancement layer is positioned on the surface of the light emitting layer on the side close to the second electrode, the second functional layer is in contact with the surface of the plasmon enhancement layer on the side close to the second electrode.
Optionally, the first functional layer includes at least one layer of a hole injection layer, a hole transport layer, and an electron blocking layer;
the second functional layer comprises at least one of an electron injection layer, an electron transport layer and a hole blocking layer which are stacked.
According to another aspect of the present invention, there is provided a light emitting panel including the organic electroluminescent device according to any one of the embodiments of the present invention.
The embodiment of the invention provides an organic electroluminescent device and a light-emitting panel, wherein the organic electroluminescent device comprises: a substrate; a first electrode located at one side of the substrate; a light-emitting layer positioned on one side of the first electrode away from the substrate; a second electrode located at one side of the light-emitting layer away from the substrate; a plasmon enhancement layer on a surface of the light emitting layer on a side close to the exciton recombination zone; the plasmon enhancement layer is composed of a main body layer and metal nano particles doped in the main body layer; according to the technical scheme provided by the embodiment of the invention, the plasmon enhancement layer is arranged on one side of the light-emitting layer, so that the rate of excitons transferred from the main body to the dye in the light-emitting layer is accelerated by utilizing the plasmon local enhancement effect, and meanwhile, the light resonance intensity emitted by the light-emitting layer is improved, and the light-emitting efficiency of the device is improved; the current density of the main light-emitting device is not required to be increased to improve the light output of the device, so that the quenching probability of triplet excitons can be reduced; in addition, the plasmon enhancement layer is arranged on one side of the light-emitting layer, so that the triplet excitons in the light-emitting layer can be prevented from being too much compared with the plasmon enhancement layer arranged in the light-emitting layer, quenching probability of the triplet excitons can be reduced, roll-off of the light-emitting efficiency of the device is prevented, and the service life and reliability of the device are ensured.
It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic cross-sectional structure of an organic electroluminescent device according to an embodiment of the present invention;
fig. 2 is a schematic cross-sectional structure of another organic electroluminescent device according to an embodiment of the present invention;
FIG. 3 is a schematic structural view of a metal nanoparticle according to an embodiment of the present invention;
FIG. 4 is a schematic structural view of another metal nanoparticle according to an embodiment of the present invention;
FIG. 5 is a schematic structural view of another metal nanoparticle according to an embodiment of the present invention;
fig. 6 is a schematic cross-sectional structure of another organic electroluminescent device according to an embodiment of the present invention;
fig. 7 is a schematic cross-sectional structure of another organic electroluminescent device according to an embodiment of the present invention.
Detailed Description
In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
An embodiment of the present invention provides an organic electroluminescent device, fig. 1 is a schematic cross-sectional structure of an organic electroluminescent device provided by the embodiment of the present invention, fig. 2 is a schematic cross-sectional structure of another organic electroluminescent device provided by the embodiment of the present invention, and referring to fig. 1 and 2, the organic electroluminescent device includes:
a substrate 10;
a first electrode 20 positioned at one side of the substrate 10;
a light emitting layer 30 located at a side of the first electrode 20 remote from the substrate 10;
a second electrode 40 located at a side of the light emitting layer 30 away from the substrate 10;
a plasmon enhancement layer 50 on a surface of the light emitting layer 30 on a side close to the exciton recombination zone; plasmon enhancement layer 50 is composed of bulk layer 51 and metal nanoparticles 52 doped in bulk layer 51; the plasmon enhancement layer 50 is used to increase the luminous efficiency of the electroluminescent device using the plasmon local enhancement effect.
Specifically, the OLED device is a current driven light emitting device, and under the condition of power on, holes enter the organic electroluminescent device from the anode, electrons enter the organic electroluminescent device from the cathode, and both of them finally reach the light emitting layer 30. The material of the light emitting layer 30 includes a host material for energy transfer and a guest material for light emission. When the electrons and holes meet, a recombination effect is generated, and an electron-hole pair is formed, so that an exciton is formed, and the exciton migrates under the action of an electric field to transfer energy to the guest material (dye) in the light emitting layer 30. After absorbing energy, electrons in the guest material transition from the ground state to the excited state, and because the excited state is unstable, electrons will transition from the excited state back to the ground state again, releasing energy, producing photons. According to the difference of the excited state energy levels of the luminescent materials, electrons release photons with different energies in the process of transition back to the ground state, and the energy determines the wavelength of light according to the formula e=hv, so that light with different colors is emitted. The substrate 10 may be a flexible substrate, and the material of the flexible substrate may be an organic polymer such as PET, PEN, PI or ultra-thin glass. The substrate 10 may be a rigid substrate, such as a glass substrate. The substrate 10 may be transparent, translucent or opaque. If the first electrode 20 is an anode layer, the second electrode 40 is a cathode; if the first electrode 20 is a cathode, the second electrode 40 is an anode.
Plasmon enhancement layer 50 is located on a side surface of light emitting layer 30 adjacent to the exciton recombination zone. Referring to fig. 1, if the light emitting layer 30 is located at a side close to the exciton recombination zone, the light emitting layer 30 is located at a side close to the first electrode 20; plasmon enhancement layer 50 is located on the surface of light emitting layer 30 on the side closer to first electrode 20. Referring to fig. 2, if the light emitting layer 30 is located at a side close to the exciton recombination zone, the light emitting layer 30 is located at a side close to the second electrode 40; the plasmon enhancement layer 50 is located on the surface of the light emitting layer 30 on the side close to the second electrode 40.
Plasmons refer to fluctuations in carrier concentration at one place in space due to coulomb interactions between carriers in a solid system with a certain carrier concentration (e.g., metal, semiconductor with a certain carrier concentration, etc.), which will inevitably cause oscillations in carrier concentration at other places. Such a meta-excitation, which is basically characterized by oscillation of carrier concentration, is called plasmon. The plasmon enhancement layer 50 is arranged at one side of the exciton recombination zone in the light-emitting layer 30, and the plasmon enhancement layer 50 enhances the resonance energy transfer from the main body to the dye by utilizing the plasmon local enhancement effect, so that the dye obtains more excitation energy; the emitted light of the light emitting layer 30 may also interact with the surface plasmon effect of the metal nanoparticles to create a near field enhancement effect.
The plasmon enhancement layer 50 has the action principle that in the electrified luminescence state of the electroluminescent device, the metal nano particles 52 can have a surface plasmon resonance effect, the surface plasmon resonance effect can have a certain spatial locality and a local enhancement characteristic, when the excitons in the luminescent layer 30 are in the near field range of the metal nano particles 52, the excitons in the luminescent layer 30 can be coupled with the surface plasmon resonance of the metal nano particles under the near field plasmon effect generated by the metal nano particles 52, so that the electric field intensity outside the metal nano particles 52 is greatly increased through charge oscillation, the transfer efficiency of the excitons from a main body to a dye in the luminescent layer 30 is accelerated, further more excitation energy is obtained by the luminescent material in the luminescent layer 30, and the luminescent efficiency of the light emitting diode is improved. In addition, the emitted light of the light emitting layer 30 can be resonantly coupled by the metal nanoparticles 52 in the plasmon enhancement layer 50 during propagation, so that the light intensity is increased under the local enhancement effect, and the resonant form of the light can be changed, thereby enhancing the light emergence rate of the light emitting device.
The current density of the main light-emitting device is not required to be increased to improve the light output of the device, so that the quenching probability of triplet excitons can be reduced; in addition, the plasmon enhancement layer 50 is disposed on one side of the light emitting layer 30, so that the triplet excitons in the light emitting layer 30 can be prevented from being too much, the quenching probability of the triplet excitons can be reduced, the roll-off of the light emitting efficiency of the device can be prevented, and the service life and reliability of the device can be ensured, compared with the case of being disposed in the light emitting layer 30.
The organic electroluminescent device provided by the embodiment of the invention comprises: a substrate 10; a first electrode 20 positioned at one side of the substrate 10; a light emitting layer 30 located at a side of the first electrode 20 remote from the substrate 10; a second electrode 40 located at a side of the light emitting layer 30 away from the substrate 10; a plasmon enhancement layer 50 on a surface of the light emitting layer 30 on a side close to the exciton recombination zone; plasmon enhancement layer 50 is composed of bulk layer 51 and metal nanoparticles 52 doped in bulk layer 51; according to the technical scheme provided by the embodiment of the invention, the plasmon enhancement layer 50 is arranged on one side of the light-emitting layer 30, and the plasmon enhancement layer 50 is used for accelerating the rate of exciton transfer to the light-emitting layer 30 by utilizing the plasmon local enhancement effect, so that the light-emitting efficiency of the device is improved; the current density of the main light-emitting device is not required to be increased to improve the light output of the device, so that the quenching probability of triplet excitons can be reduced; in addition, the plasmon enhancement layer 50 is disposed on one side of the light emitting layer 30, so that the triplet excitons in the light emitting layer 30 can be prevented from being too much, the quenching probability of the triplet excitons can be reduced, the roll-off of the light emitting efficiency of the device can be prevented, and the service life and reliability of the device can be ensured, compared with the case of being disposed in the light emitting layer 30.
On the basis of the above-described embodiments, in one embodiment of the present invention, the material of the host layer 51 is the same as the host material of the light emitting layer 30;
wherein the overlap of the surface plasmon resonance spectrum of the metal nanoparticle 52 with the emission spectrum of the host material is 20% or more, and the overlap of the surface plasmon resonance spectrum of the metal nanoparticle 52 with the absorption spectrum of the guest material is 20% or more.
Specifically, by providing the material of the main body layer 51 to be the same as the main body material of the light emitting layer 30, the preparation processes of the light emitting layer 30 and the plasmon enhancement layer 50 can be simplified; it is also possible to prevent a difference in dielectric constant between the material of the host layer 51 and the host material of the light emitting layer 30, resulting in a decrease in external quantum efficiency of actual emission of the light emitting device.
The overlapping degree of the surface plasmon resonance spectrum of the metal nanoparticle 52 and the emission spectrum of the host material is 20% or more, and it is understood that the wavelength range of the surface plasmon resonance wavelength of the metal nanoparticle 52 has the same wavelength range interval as the wavelength range of the emission wavelength of the host material; and the same wavelength range section occupies 20% or more than 20% of the wavelength range of the emission wavelength of the host material. The overlapping degree of the surface plasmon resonance spectrum of the metal nanoparticle 52 and the absorption spectrum of the guest material is 20% or more, and it is understood that the wavelength range of the surface plasmon resonance wavelength of the metal nanoparticle 52 has the same wavelength range interval as the wavelength range of the emission wavelength of the guest material; and the same wavelength range region occupies 20% or more of the wavelength range of the emission wavelength of the guest material.
According to the embodiment of the invention, the overlapping degree of the surface plasmon resonance spectrum of the metal nano particle 52 and the emission spectrum of the host material is more than or equal to 20%, and the overlapping degree of the surface plasmon resonance spectrum of the metal nano particle 52 and the absorption spectrum of the guest material is more than or equal to 20%, so that the plasmon and exciton in the host generate stronger resonance effect, and energy can be more efficiently transferred from the host to the dye, thereby enhancing the resonance energy transfer from the host to the dye and improving the luminous efficiency of the device.
On the basis of the above embodiments, fig. 3 is a schematic structural diagram of a metal nanoparticle 52 according to an embodiment of the present invention, and referring to fig. 3, in an embodiment of the present invention, the metal nanoparticle 52 includes a metal core 521 and a dielectric layer 522 coated on the outer side of the metal core 521.
Specifically, the metal nanoparticle 52 includes a metal core 521 and a dielectric layer 522 coated on the outside of the metal core 521, which can prevent excitons in the plasmon enhancement layer 50 from directly contacting the metal core 521, resulting in quenching of the excitons. Wherein the material of the metal core 521 includes, but is not limited to, at least one of Au, ag, al, zn, cu, cr, cd and Pt, for example. The material of dielectric layer 522 includes, but is not limited to, at least one of titanium oxide, zinc oxide, and silicon oxide, for example. Optionally, the thickness of the dielectric layer 522 ranges from 1nm to 30nm, and may be set to 2nm, 5nm, 10nm, 20nm, or the like as required; the volume of the metal nano-particles 52 is prevented from being too large due to the too large thickness of the dielectric layer 522, and the doping quantity of the metal nano-particles 52 is influenced; and to prevent the thickness of dielectric layer 522 from being too small to easily cause quenching of excitons. Referring to fig. 3 to 5, it is exemplarily shown that the metal nanoparticles 52 may be spherical, ellipsoidal, or rod-shaped, respectively. The shape of the metal nanoparticles 52 may be set according to actual needs.
Based on the above embodiments, in one embodiment of the present invention, the thickness of the body layer 51 ranges from 5nm to 50nm; can be set to 10nm, 20nm, 30nm, 40nm or the like as required. The length L of the metal nanoparticles 52 ranges from 1nm to 50nm; may be set to 2nm, 5nm, 10nm, 20nm, 30nm, 40nm or the like as required. The doping volume ratio of the metal nano particles 52 ranges from 1% to 20%; may be set to 2%, 5%, 10%, 15%, or the like as required.
Specifically, when the metal nanoparticle 52 is spherical, the length L of the metal nanoparticle 52 can be understood as the length of a segment having both ends on the spherical surface and passing through the center of the sphere. When the metal nanoparticle 52 is ellipsoidal, the length L of the metal nanoparticle 52 can be understood as the length of the major axis in the elliptical cross section of the metal nanoparticle 52. When the metal nanoparticle 52 is rod-shaped, the length L of the metal nanoparticle 52 is the distance between the two ends of the rod-shaped metal nanoparticle 52. The length of the metal nanoparticle 52 is set to be 1nm to 50nm, and the resonance wavelength of the plasmon can be ensured to be in the visible light range. The resonance wavelength of the plasmon is related to the size of the metal nanoparticle 52, and the larger the volume 52 of the metal nanoparticle is, the red shift of the resonance wavelength and the width of the edge (half-width is large).
Alternatively, the plasmon resonance wavelength is positively correlated with the aspect ratio of the metal nanoparticles 52; specifically, the resonance wavelength of the plasmon is also related to the shape of the nanoparticle, and the larger the aspect ratio of the nanoparticle, the red shift of the resonance wavelength. The resonance wavelength red-shifts to mean that the resonance wavelength is increasingly closer to the red wavelength.
In addition, setting the thickness range of the host layer 51 to 5nm to 50nm can prevent the thickness of the host layer 51 from being too large to affect the operating voltage of the light emitting device, and prevent the thickness of the host layer 51 from being too small to affect the doping amount of the metal nanoparticles 52. The doping volume ratio of the metal nanoparticles 52 is set to be in the range of 1% -20%, so that the influence of too large doping volume ratio of the metal nanoparticles 52 on the light transmittance of the plasmon enhancement layer 50 can be prevented, and the influence of the incontinuous main body layer 51 and the influence of the photoelectric property of the main body layer 51 due to too large doping volume ratio of the metal nanoparticles 52 can be prevented. In addition, if the doping volume ratio of the metal nanoparticles 52 is too large, the exciton density in the light emitting layer 30 is too large, so that the probability of quenching of exciton states increases. Setting the range of the doping volume ratio of the metal nanoparticles 52 to be greater than or equal to 1% can prevent the effect of the plasmon enhancement layer 50 from being affected by too small a doping volume ratio of the metal nanoparticles 52.
With continued reference to fig. 1 and 2, in one embodiment of the present invention, the organic electroluminescent device further includes: a first functional layer 60 and a second functional layer 70; the first functional layer 60 is located between the first electrode 20 and the light emitting layer 30; the second functional layer 70 is located between the second electrode 40 and the light emitting layer 30. Wherein, when plasmon enhancement layer 50 is located on the surface of light emitting layer 30 on the side close to first electrode 20, first functional layer 60 is in contact with the surface of plasmon enhancement layer 50 on the side close to first electrode 20; when plasmon enhancement layer 50 is located on the surface of light emitting layer 30 on the side close to second electrode 40, second functional layer 70 is in contact with the surface of plasmon enhancement layer 50 on the side close to second electrode 40. Taking the first electrode 20 as an anode and the second electrode 40 as a cathode, the first functional layer 60 includes at least one of a hole injection layer 61, a hole transport layer 62 and an electron blocking layer 63; the second functional layer 70 includes at least one of an electron injection layer 71, an electron transport layer 72, and a hole blocking layer 73, which are stacked.
Fig. 6 is a schematic cross-sectional structure of another organic electroluminescent device according to an embodiment of the present invention, and fig. 7 is a schematic cross-sectional structure of another organic electroluminescent device according to an embodiment of the present invention, and referring to fig. 6 and 7, a first functional layer 60 is exemplarily shown to include a hole injection layer 61, a hole transport layer 62, and an electron blocking layer 63; the second functional layer 70 includes an electron injection layer 71, an electron transport layer 72, and a hole blocking layer 73, which are stacked.
Specifically, the anode functions to inject holes into the highest level full orbit (HOMO, highest Occupied Molecular Orbital) of the light emitting material of the light emitting layer 30, and therefore, a metal or transparent conductive oxide with a higher Work Function is used for the layer to match the energy of the valence band of the light emitting material. The hole transport layer 62 is used to enable holes injected from the anode to flow to the light emitting layer 30 through the hole transport layer 62, and the electron blocking layer 63 is used to block electrons from the cathode from directly flowing to the anode. A hole injection layer 61 may be further added between the anode and the hole transport layer 62, mainly because the energy barrier between the anode and the hole transport layer 62 is large, which may cause the driving voltage of the device to increase, so that a layer of material between the anode and the hole transport layer 62 is added to increase the efficiency of hole injection into the hole transport layer 62.
The cathode is used to inject electrons into the lowest level hollow orbit (LUMO, lowest Unoccupied Molecular Orbital) of the light emitting layer 30, and in order to effectively inject electrons into the light emitting layer 30, a metal with a low work function is generally selected, and the lower the work function, the smaller the energy gap between the metal and the light emitting layer 30, the more easily the electrons enter the light emitting layer 30, so as to improve the combination probability of electrons and holes, increase the light emitting efficiency, and reduce the initial voltage. The electron transport layer 72 functions so that electrons injected from the cathode can flow to the light emitting layer 30 through the electron transport layer 72. The hole blocking layer 73 serves to block holes from the anode from flowing directly to the cathode. So that electrons and holes are recombined in the light emitting layer 30 and emit light. Also, an electron injection layer 71 may be added between the cathode and the electron transport layer 72 to enhance the efficiency of electron injection into the electron transport layer 72.
The embodiment of the invention also provides a light-emitting panel, which comprises the organic electroluminescent device in any embodiment. Has the same technical effects and is not described in detail herein.
Note that the above is only a preferred embodiment of the present invention and the technical principle applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, while the invention has been described in connection with the above embodiments, the invention is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the invention, which is set forth in the following claims.
Claims (10)
1. An organic electroluminescent device, comprising:
a substrate;
a first electrode located at one side of the substrate;
a light-emitting layer positioned on one side of the first electrode away from the substrate;
a second electrode located at one side of the light-emitting layer away from the substrate;
a plasmon enhancement layer on a surface of the light emitting layer on a side close to the exciton recombination zone; the plasmon enhancement layer is composed of a main body layer and metal nano particles doped in the main body layer; the plasmon enhancement layer is used for increasing the luminous efficiency of the electroluminescent device by utilizing the plasmon local enhancement effect.
2. The organic electroluminescent device according to claim 1, wherein the material of the light-emitting layer includes a host material for energy transfer and a guest material for light emission; the material of the main body layer is the same as the main body material of the light-emitting layer;
the overlap of the surface plasmon resonance spectrum of the metal nanoparticle with the emission spectrum of the host material is greater than or equal to 20%, and the overlap of the surface plasmon resonance spectrum of the metal nanoparticle with the absorption spectrum of the guest material is greater than or equal to 20%.
3. The organic electroluminescent device of claim 1, wherein the metal nanoparticle comprises a metal core and a dielectric layer coating the outside of the metal core.
4. An organic electroluminescent device according to claim 3, wherein the thickness of the dielectric layer is in the range of 1nm to 30nm.
5. The organic electroluminescent device of claim 1, wherein the metal nanoparticles are spherical, ellipsoidal, or rod-shaped.
6. The organic electroluminescent device of claim 1, wherein the thickness of the host layer ranges from 5nm to 50nm; the length of the metal nano particles ranges from 1nm to 50nm;
the doping volume ratio of the metal nano particles is in the range of 1-20%.
7. The organic electroluminescent device as claimed in claim 1, wherein,
the side of the light-emitting layer close to the exciton recombination zone is the side of the light-emitting layer close to the first electrode; the plasmon enhancement layer is positioned on the surface of the light-emitting layer, which is close to one side of the first electrode;
or, the side of the light-emitting layer close to the exciton recombination zone is the side of the light-emitting layer close to the second electrode; the plasmon enhancement layer is positioned on the surface of the light-emitting layer, which is close to one side of the second electrode.
8. The organic electroluminescent device of claim 7, further comprising:
a first functional layer located between the first electrode and the light emitting layer;
a second functional layer located between the second electrode and the light emitting layer;
wherein when the plasmon enhancement layer is positioned on the surface of the light emitting layer on the side close to the first electrode, the first functional layer is in contact with the surface of the plasmon enhancement layer on the side close to the first electrode; when the plasmon enhancement layer is positioned on the surface of the light emitting layer on the side close to the second electrode, the second functional layer is in contact with the surface of the plasmon enhancement layer on the side close to the second electrode.
9. The organic electroluminescent device as claimed in claim 8, wherein,
the first functional layer comprises at least one layer of a hole injection layer, a hole transport layer and an electron blocking layer;
the second functional layer comprises at least one of an electron injection layer, an electron transport layer and a hole blocking layer which are stacked.
10. A light-emitting panel comprising the organic electroluminescent device as claimed in any one of claims 1 to 9.
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| CN202311778024.5A CN117750821A (en) | 2023-12-21 | 2023-12-21 | Organic electroluminescent device and light-emitting panel |
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| CN202311778024.5A CN117750821A (en) | 2023-12-21 | 2023-12-21 | Organic electroluminescent device and light-emitting panel |
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