CN112467049A

CN112467049A - Structure of OLED device

Info

Publication number: CN112467049A
Application number: CN202011293686.XA
Authority: CN
Inventors: 吕磊
Original assignee: Semiconductor Integrated Display Technology Co Ltd
Current assignee: Semiconductor Integrated Display Technology Co Ltd
Priority date: 2020-11-18
Filing date: 2020-11-18
Publication date: 2021-03-09

Abstract

The invention discloses a structure of an OLED device, which comprises: an energy-level-matching base layer provided with an initial light-emitting layer and an electrode layer; newly adding a luminescent layer close to one side of the electrode layer; and an ITL material layer disposed between the newly added light emitting layer and the initial light emitting layer to reduce a transport barrier for electrons and holes. The structure of the OLED device overcomes the problem of low luminous efficiency of a green light device in the prior art, and further improves the brightness of the green light device under the condition of not increasing voltage.

Description

Structure of OLED device

Technical Field

The invention relates to the technical field of OLED display, in particular to a structure of an OLED device.

Background

Compared with the traditional AMOLED display technology, the silicon-based OLED micro-display takes the monocrystalline silicon chip as the substrate, and the pixel size is smaller and the integration level is higher by means of the mature CMOS process, so that the silicon-based OLED micro-display can be manufactured into a near-to-eye display product which is comparable to large-screen display and is widely concerned. Based on the technical advantages and wide market, in the fields of military and consumer electronics, the silicon-based OLED micro-display will raise the new wave of near-to-eye display, and bring unprecedented visual experience for users.

Silicon-based OLEDs are widely applied to the VR/AR field, wherein most of AR glasses adopt an optical waveguide technology, and no matter a diffraction optical waveguide or a geometric optical waveguide, light is lost in a large proportion in the processes of coupling in and out of the waveguide and transmitting, and the loss is even up to more than 90%; in order to satisfy the brightness requirement of the display, i.e., the requirement of the body of the light emitting unit to have higher brightness, the device has to have higher efficiency and brightness in the silicon-based OLED.

In addition to the conventional use of high-efficiency materials, the method for improving efficiency and brightness in green devices usually adopts a stacked structure (Tandem structure), and commonly adopts green devices with 2-stack structure or 3-stack structure, as shown in fig. 1 and fig. 2, a Tandem device can inherently increase the efficiency and brightness of the device, but the driving voltage is also increased synchronously and linearly, and the driving voltage of an OLED is limited by an IC, so the number of stacks in the Tandem structure is limited, and the voltage which can be provided by an IC in a silicon-based OLED can meet the 2-stack structure, and if the voltage exceeds the 3-stack structure, the risk exists, so the 2-stack structure is commonly used to increase the brightness. The green devices shown in fig. 1 and 2 at the present stage have low luminous efficiency.

Disclosure of Invention

The invention aims to provide a structure of an OLED device, which overcomes the problem of low luminous efficiency of a green light device in the prior art, and further improves the brightness of the green light device under the condition of not increasing voltage.

In order to achieve the above object, the present invention provides a structure of an OLED device, including: an energy-level-matching base layer provided with an initial light-emitting layer and an electrode layer; newly adding a luminescent layer close to one side of the electrode layer; and an ITL material layer disposed between the newly added light emitting layer and the initial light emitting layer to reduce a transport barrier for electrons and holes.

Preferably, the electrode layers comprise an anode and a cathode; wherein: the newly added light-emitting layer is close to one side of the cathode, and the ITL material layer is arranged between the cathode and the initial light-emitting layer; or the newly added light-emitting layer is close to one side of the anode, and the ITL material layer is arranged between the anode and the initial light-emitting layer; or the initial light-emitting layer comprises a first light-emitting layer and a second light-emitting layer, the new light-emitting layer comprises a third light-emitting layer and a fourth light-emitting layer, and the ITL material layer comprises a first ITL layer and a second ITL layer, wherein the third light-emitting layer is close to one side of the anode, the first ITL layer is arranged between the anode and the first light-emitting layer, the fourth light-emitting layer is close to one side of the cathode, and the second ITL layer is arranged between the cathode and the second light-emitting layer.

Preferably, the material of the newly added light-emitting layer on the side close to the anode is configured as a host material of a partial hole; or the material of the newly added light emitting layer on the side close to the cathode is configured as a host material of a bias electron.

Preferably, the ITL material layer is configured to employ a bipolar material or a host material adjacent to the initial light emitting layer.

Preferably, the thickness of the newly added light emitting layer is configured to be 10-30nm, and the doping concentration of the G-dopant is 6% -8%.

Preferably, the doping concentration of the G-dopant is 6%.

Preferably, the thickness of the ITL material layer is configured to be 1-10 nm.

Preferably, the thickness of the ITL material layer is configured to be 3-6 nm.

According to the technical scheme, the final OLED device structure has higher brightness by utilizing the newly added light emitting layer and the ITL material layer, can be applied to various series of optical waveguide products, and further reduces the current of the device under the same brightness by utilizing the matching of the ITL material layer and the light emitting layer, thereby prolonging the service life of the device.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic structural diagram of a structure of a two-stack OLED device in the prior art;

FIG. 2 is a schematic structural diagram of a structure of a prior art three-stack OLED device;

fig. 3 is a schematic structural view illustrating the structure of an OLED device of embodiment 1 of the present invention;

fig. 4 is a schematic structural view illustrating the structure of an OLED device of embodiment 2 of the present invention; and

fig. 5 is a schematic structural view illustrating the structure of an OLED device of embodiment 3 of the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, unless otherwise specified, the directional words included in the terms such as "up, down, left, right" and the like merely represent the directions of the terms in a conventional use state or are colloquially known by those skilled in the art, and should not be construed as limiting the terms.

Fig. 1 and 2 are schematic structural diagrams of an OLED device in the prior art, and the present invention proposes the following structures in order to overcome the problem of low light emitting efficiency of a green device in the prior art, as shown in fig. 3, 4 and 5, the present invention provides a structure of an OLED device, which includes: an energy-level-matching base layer provided with an initial light-emitting layer and an electrode layer; newly adding a luminescent layer close to one side of the electrode layer; and an ITL material layer, wherein the ITL interface layer or the connection layer is arranged between the newly added luminous layer and the initial luminous layer to reduce the transmission barrier of electrons and holes.

The new luminescent layer is different from the initial luminescent layer, and the ITL material layer corresponding to the new luminescent layer is added to the new luminescent layer. The electrode layer comprises an anode and a cathode, and the light-emitting layer is EML-G. The initial light emitting layer includes an EML-G-1 as a first green light emitting layer and an EML-G-2 as a second green light emitting layer, an Anode as an Anode, a hole injection layer as an HIL, a hole injection layer as an HTL, an electron injection layer as an EIL, a Cathode as a Cathode, and a light coupling-out layer as a CPL, as shown in fig. 1.

Example 1

As shown in fig. 3, conventional materials are used for the materials of the respective layers in this example 1.

The newly added luminescent layer EML-G-3 is close to one side of the cathode, the newly added luminescent layer EML-G-3 selects a main body material (N type) with a bias electron, the thickness is 10-30nm, the doping concentration of G-dopant (green light doping material) is controlled to be 6% -8%, and the preferred concentration is 6%. The ITL material layer is arranged between the cathode and the initial light-emitting layer, and can be selected to be a material of EML-G-2host as a connecting layer so as to reduce the injection barrier with the EML-G-2, or a bipolar material (P-N type) so as to reduce the transmission barrier of electrons and holes; wherein, the thickness of the ITL layer is controlled within the range of 1-10nm, and the preferable scheme is 3-6 nnm.

Example 2

As shown in fig. 4, conventional materials are used for the materials of the respective layers in this example 2.

And the newly added luminescent layer is close to one side of the anode, the newly added luminescent layer G-Host (green light main material) selects a main material (P type) with partial holes, the thickness range is 10-30nm, the doping concentration of G-dopant is controlled to be 6-8%, and the preferred concentration is 6%. The ITL material layer is arranged between the cathode and the initial light-emitting layer, and can be selected to be a material of EML-G-1host as a connecting layer to reduce the injection barrier with EML-G-1 or a bipolar material (P-N type) to reduce the transmission barrier of electrons and holes; wherein the thickness of the ITL layer is controlled in the range of 1-10nm, preferably 3-6 nnm.

Example 3

As shown in fig. 5, conventional materials are used for the materials of the respective layers in this example 2.

The initial light-emitting layer comprises a first light-emitting layer EML-G-1 and a second light-emitting layer EML-G-2, the newly added light-emitting layer comprises a third light-emitting layer EML-G-3 and a fourth light-emitting layer EML-G-4, the ITL material layer comprises a first ITL layer ITL-1 and a second ITL layer ITL-2, the EML-G-3 is close to one side of the anode, the G-Host of the light-emitting layer EML-G-3 selects a main body material (P type) with a bias hole, the thickness range is 10-30nm, the doping concentration of G-dopant is controlled to be 6-8%, and the preferred concentration is 6%; the G-Host of the luminescent layer EML-G-4 at the side of the EML-G-4 close to the cathode selects a main body material (N type) with a bias electron, the thickness ranges from 10nm to 30nm, the doping concentration of G-dopant is controlled to be 6 percent to 8 percent, the preferred concentration is 6 percent, and the ITL1 material can be selected as a material of EML-G-1Host to be used as a connecting layer to reduce the injection barrier with the EML-G-1 or a bipolar material (P-N type) to reduce the transmission barrier of electrons and holes; the ITL2 material can be selected as a connecting layer of a material of EML-G-2host to lower the injection barrier with EML-G-2, or a bipolar material (P-N type) to lower the transport barrier of electrons and holes; wherein the thickness of ITL is controlled in the range of 1-10nm, preferably 3-6 nm.

The

above embodiments

1, 2 and 3 can achieve the effects of improving the green light emitting efficiency, brightness and lifetime, and the driving voltage of the G-OLED device with the structure used in the present invention is close to the voltage of the 2stack device (fig. 1), but has higher brightness.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A structure of an OLED device, comprising:

an energy-level-matching base layer provided with an initial light-emitting layer and an electrode layer;

newly adding a luminescent layer close to one side of the electrode layer; and

and the ITL material layer is arranged between the newly added luminous layer and the initial luminous layer so as to reduce the transmission barrier of electrons and holes.

2. The structure of the OLED device of claim 1 wherein the electrode layers include an anode and a cathode; wherein:

the newly added light-emitting layer is close to one side of the cathode, and the ITL material layer is arranged between the cathode and the initial light-emitting layer; or

The newly added light-emitting layer is close to one side of the anode, and the ITL material layer is arranged between the anode and the initial light-emitting layer; or

The initial light emitting layer includes a first light emitting layer and a second light emitting layer, the additional light emitting layer includes a third light emitting layer and a fourth light emitting layer, and the ITL material layer includes a first ITL layer and a second ITL layer, wherein the third light emitting layer is adjacent to a side of the anode, and the first ITL layer is interposed between the anode and the first light emitting layer, the fourth light emitting layer is adjacent to a side of the cathode, and the second ITL layer is interposed between the cathode and the second light emitting layer.

3. The structure of the OLED device of claim 2,

the material of the newly added light-emitting layer on the side close to the anode is configured as a main body material of a partial hole; or

The material of the newly added light emitting layer on the side close to the cathode is configured as a host material of a bias electron.

4. The structure of the OLED device of claim 1, wherein the ITL material layer is configured to employ a bipolar material or host material adjacent to the initial light-emitting layer.

5. The structure of the OLED device according to claim 1, wherein the thickness of the newly added light-emitting layer is configured to be 10-30nm, and the doping concentration of G-dopant is 6% -8%.

6. The structure of the OLED device of claim 5 wherein the G-dopant concentration is 6%.

7. The structure of the OLED device of claim 1, wherein the thickness of the ITL material layer is configured to be 1-10 nm.

8. The structure of the OLED device of claim 7, wherein the thickness of the ITL material layer is configured to be 3-6 nm.