阅读说明：本技术 基于转移印刷绝缘朗缪尔单层的高精度图案化led漏电流阻挡层及其制备方法 (High-precision patterned LED leakage current blocking layer based on transfer printing insulation Langmuir single layer and preparation method thereof ) 是由 李福山 郑悦婷 孟汀涛 赵等临 胡海龙 郭太良 于 2021-08-24 设计创作，主要内容包括：本发明提出一种基于转移印刷绝缘朗缪尔单层的高精度图案化LED漏电流阻挡层及其制备方法,通过在LED中利用朗缪尔单层制备技术和转移印刷技术引入高精度图案化的绝缘层,以缩小发光单元尺寸及消除漏电流,可实现高发光效率超高分辨率发光器件的制备。本发明的漏电流阻挡层利用朗缪尔单层制备技术获取,绝缘材料体系局限性小,可选择范围广。利用朗缪尔单层制备技术及转移印刷技术获取的漏电流阻挡层,免去了光刻工艺显影刻蚀过程中的溶剂污染,将其应用于LED中,可降低甚至消除器件中的漏电流,减少能量损耗,实现高效发光,配合RGB单色发光材料或白光发光材料,可实现高分辨率全彩LED点阵。(The invention provides a high-precision patterned LED leakage current barrier layer based on transfer printing of an insulating Langmuir monolayer and a preparation method thereof. The leakage current barrier layer is obtained by utilizing a Langmuir single-layer preparation technology, and an insulating material system has small limitation and wide selectable range. The leakage current barrier layer obtained by utilizing the Langmuir single-layer preparation technology and the transfer printing technology avoids solvent pollution in the developing and etching process of the photoetching process, can reduce or even eliminate leakage current in a device when being applied to an LED, reduces energy loss, realizes high-efficiency luminescence, and can realize a high-resolution full-color LED dot matrix by matching with an RGB single-color luminescent material or a white light luminescent material.)

1. A preparation method of a high-precision patterning LED leakage current barrier layer based on transfer printing of an insulating Langmuir monolayer is characterized by comprising the following steps: introducing a patterned insulating layer by utilizing a Langmuir single-layer preparation technology and a transfer printing technology to form a leakage current blocking layer, so as to realize patterning and leakage current elimination;

the Langmuir monolayer preparation technology is used for enabling an insulating material to form a compact and orderly arranged insulating monolayer;

according to the transfer printing technology, the seal is adopted to grab and release the insulating single layer, so that the insulating single layer is transferred from the sub-phase liquid level to the target substrate.

2. The method of preparing a high precision patterned LED leakage current barrier layer based on transfer printing of an insulated langmuir monolayer as claimed in claim 1, wherein: the Langmuir monolayer preparation technique specifically comprises the following steps:

step A1: dispersing an insulating material at an interface between the subphase solution and the atmosphere;

step A2: the area of the subphase liquid surface is compressed by utilizing the slide barrier, so that the insulating material forms a compact single layer which is orderly arranged.

3. The method of preparing a high precision patterned LED leakage current barrier layer based on transfer printing of an insulated langmuir monolayer as claimed in claim 1, wherein: the transfer printing technique specifically comprises the steps of:

step B1: selectively grabbing the compact insulating monolayer by using a patterned stamp;

step B2: transferring the stamp and the grabbed insulating monolayer onto a target substrate together;

step B3: and stripping the seal from the insulating single layer to finish the transfer printing process.

4. The method of preparing a high precision patterned LED leakage current barrier layer based on transfer printing of an insulated langmuir monolayer as claimed in claim 3, wherein: the adhesion force between the patterned stamp and the material of the insulating monolayer is larger than that between the target substrate and the material of the insulating monolayer.

5. A high-precision patterned LED fabricated by the method of any of claims 1-4 using the transfer printing insulating langmuir monolayer based high-precision patterned LED leakage current barrier layer fabrication method, wherein the functional layers are, in order: an anode, a hole injection layer, a hole transport layer, a high-precision patterned light emitting layer, an electron transport layer, and a cathode, wherein the high-precision patterned light emitting layer is formed by filling the patterned insulating monolayer with an electroluminescent material.

6. The high-precision patterned LED according to claim 6, wherein: the anode is made of metal oxide material and is transparent in visible light wave band, and the square resistance value is less than 300 omega; the thickness is 100-200 nm; the hole injection layer is made of one of PEDOT, PSS, molybdenum oxide, nickel oxide and cuprous thiocyanate.

7. The high-precision patterned LED according to claim 6, wherein: the valence band energy level structure of the hole transport layer is matched with the hole injection layer and the high-precision patterned light-emitting layer; the conduction band energy level structure of the electron transport layer is matched with the cathode and the high-precision patterned light-emitting layer.

8. The high-precision patterned LED according to claim 6, wherein: the energy level structure of the electroluminescent material is matched with the hole transport layer and the electron transport layer.

9. The high-precision patterned LED according to claim 8, wherein: the electroluminescent material is one of inorganic luminescent material and organic luminescent material, or a mixture of a plurality of inorganic luminescent materials and organic luminescent materials; the insulating material is an insulating organic material or an insulating inorganic material.

10. The method for preparing the high-precision patterned LED according to claim 5, comprising the following steps:

step S1: depositing an anode of an LED on a substrate; step S2: depositing a hole injection layer on an anode of the LED; step S3: depositing a hole transport layer on a hole injection layer of the LED; step S4: transfer printing an insulating single layer based on Langmuir single layer preparation technology onto a hole transport layer of an LED with a high-precision patterned stamp; step S5: filling the patterned insulating monolayer with an electroluminescent material to form a high-precision patterned light-emitting layer of the LED; step S6: depositing an electron transport layer on the high-precision patterned light emitting layer of the LED; step S7: a metal cathode is deposited on the electron transport layer of the LED.

Technical Field

The invention belongs to the technical field of high-resolution LED preparation, and particularly relates to a high-precision patterned LED leakage current barrier layer based on transfer printing of an insulating Langmuir monolayer and a preparation method thereof.

Background

In daily life, more than 80% of external information received by human beings is obtained by vision. The display technique is visually closely related and its importance is self-evident. With the continuous development of scientific technology, people no longer satisfy traditional display devices, and directions such as flexible display, wearable devices, virtual/augmented reality (AR/VR) technology and the like have attracted attention.

As an indispensable part of AR/VR technology, near-eye display devices have direct effects on the visual experience of users due to the performance of response speed, contrast, color gamut, resolution, and the like. Compare in traditional display device, the pixel point of near-to-eye display device and the distance of people's eye are extremely short, are used for so short viewing distance with traditional high definition display device's pixel density, and adjacent pixel also can form very big contained angle with people's eye, and the pixel border feels strong, produces "screen window effect", influences the picture and reappears the authenticity and simultaneously, also arouses user's dizzy sense easily. Therefore, for the development of smart displays, it is important to develop ultra-high resolution display technologies.

In the development direction of high-resolution display, LEDs are distinguished from CRT, PDP, FED, LCD and other display technologies by their unique advantages of active light emission, thinness, light weight, wide color gamut, high efficiency, fast response and the like. However, holes are often formed in the light emitting layer of the thin film LED device during the deposition process, and leakage current is generated inside the device during lighting, so that part of the electrical energy is lost in the form of heat, thereby reducing the light emitting efficiency of the device. Therefore, reducing the generation of leakage current is the key to improving the luminous efficiency of the LED.

Disclosure of Invention

In view of the above, in order to overcome the defects and shortcomings of the prior art, the present invention is directed to provide a high-precision patterned LED leakage current blocking layer based on transfer printing of an insulating langmuir monolayer and a method for preparing the same, which are mainly applied to the preparation of an ultra-high resolution light emitting device with high luminous efficiency in an LED.

The LED leakage current blocking layer provided by the invention realizes high-precision patterning and leakage current elimination mainly by transferring and printing the insulated Langmuir single layer, and has certain significance for developing an ultrahigh-resolution LED with high luminous efficiency. High-precision patterning and leakage current elimination are realized by transferring and printing the insulated Langmuir single layer, the patterning can be customized, and the preparation of a high-luminous-efficiency ultrahigh-resolution light-emitting device can be realized when the method is applied to an LED.

The method can realize the preparation of a high-luminous-efficiency ultrahigh-resolution light-emitting device by introducing a high-precision patterned insulating layer in an LED by utilizing a Langmuir single-layer preparation technology and a transfer printing technology to reduce the size of a light-emitting unit and eliminate leakage current. The leakage current barrier layer is obtained by utilizing a Langmuir single-layer preparation technology, and an insulating material system has small limitation and wide selectable range. The leakage current barrier layer obtained by utilizing the Langmuir single-layer preparation technology and the transfer printing technology avoids solvent pollution in the developing and etching process of the photoetching process, can reduce or even eliminate leakage current in a device when being applied to an LED, reduces energy loss, realizes high-efficiency luminescence, and can realize a high-resolution full-color LED dot matrix by matching with an RGB single-color luminescent material or a white light luminescent material.

The invention specifically adopts the following technical scheme:

a preparation method of a high-precision patterning LED leakage current barrier layer based on transfer printing of an insulating Langmuir monolayer is characterized by comprising the following steps: patterning and leakage current elimination are achieved by introducing a patterned insulating layer using langmuir monolayer fabrication techniques and transfer printing techniques to form a leakage current blocking layer.

The Langmuir monolayer preparation technology is used for enabling an insulating material to form a compact and orderly arranged insulating monolayer;

according to the transfer printing technology, the seal is adopted to grab and release the insulating single layer, so that the insulating single layer is transferred from the sub-phase liquid level to the target substrate.

The pattern of the stamp can be customized according to specific requirements.

Further, the langmuir monolayer preparation technique specifically comprises the following steps:

step A1: dispersing an insulating material at an interface between the subphase solution and the atmosphere;

step A2: the area of the subphase liquid surface is compressed by utilizing the slide barrier, so that the insulating material forms a compact single layer which is orderly arranged.

Further, the transfer printing technique specifically comprises the steps of:

step B1: selectively grabbing the compact insulating monolayer by using a patterned stamp;

step B2: transferring the stamp and the grabbed insulating monolayer onto a target substrate together;

step B3: and stripping the seal from the insulating single layer to finish the transfer printing process.

The above two technologies can also be simplified into the following steps:

step 1: dispersing an insulating material at an interface between the subphase solution and the atmosphere;

step 2: reducing the area of the sub-phase liquid level to form a single layer of tightly arranged insulating materials;

and step 3: selectively grabbing the insulating single layer formed in the step 2 by using a high-precision patterned stamp;

and 4, step 4: and releasing the insulating single layer on the seal onto a target substrate to finish transfer.

Further, the adhesion force between the patterned stamp and the material of the insulating monolayer is greater than the adhesion force between the target substrate and the material of the insulating monolayer.

And, a high-precision patterned LED, characterized in that, made by the above-mentioned method for preparing a high-precision patterned LED leakage current barrier layer based on transfer printing of an insulating langmuir monolayer, each functional layer is in turn: an anode, a hole injection layer, a hole transport layer, a high-precision patterned light emitting layer, an electron transport layer, and a cathode, wherein the high-precision patterned light emitting layer is formed by filling the patterned insulating monolayer with an electroluminescent material.

Furthermore, the anode is made of metal oxide materials, is transparent in a visible light wave band, and has a square resistance value smaller than 300 omega; the thickness is 100-200 nm; the hole injection layer is made of one of PEDOT, PSS, molybdenum oxide, nickel oxide and cuprous thiocyanate.

Further, the valence band energy level structure of the hole transport layer is matched with the hole injection layer and the high-precision patterned light emitting layer; the conduction band energy level structure of the electron transport layer is matched with the cathode and the high-precision patterned light-emitting layer.

Further, the energy level structure of the electroluminescent material is matched with the hole transport layer and the electron transport layer.

Further, the electroluminescent material is one of inorganic luminescent material and organic luminescent material, or a mixture of a plurality of materials; the insulating material is an insulating organic material or an insulating inorganic material. The inorganic luminescent material can adopt perovskite, perovskite quantum dots, indium phosphide quantum dots and cadmium quantum dots.

Further, the preparation method comprises the following steps:

step S1: depositing an anode of an LED on a substrate; step S2: depositing a hole injection layer on an anode of the LED; step S3: depositing a hole transport layer on a hole injection layer of the LED;

step S4: transfer printing an insulating single layer based on Langmuir single layer preparation technology onto a hole transport layer of an LED with a high-precision patterned stamp; step S5: filling the patterned insulating monolayer with an electroluminescent material to form a high-precision patterned light-emitting layer of the LED; step S6: depositing an electron transport layer on the high-precision patterned light emitting layer of the LED; step S7: a metal cathode is deposited on the electron transport layer of the LED.

Compared with the prior art, the advantages of the invention and the preferred scheme thereof comprise:

1) the leakage current barrier layer is obtained by utilizing a Langmuir single-layer preparation technology, and an insulating material system has small limitation and wide selectable range.

2) The leakage current barrier layer is obtained by utilizing a Langmuir single-layer preparation technology and a transfer printing technology, and compared with a common photoetching process for high-precision patterning, the leakage current barrier layer avoids solvent pollution in the developing and etching process.

3) The leakage current blocking layer is applied to the LED, can reduce or even eliminate leakage current in a device, reduces energy loss and realizes high-efficiency light emission.

4) The high-precision patterning of the invention can be matched with RGB single-color luminescent materials or white light luminescent materials to realize high-resolution full-color LED dot matrix.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

figure 1 is a schematic diagram of langmuir monolayer fabrication techniques and transfer printing techniques in accordance with embodiments of the present invention;

figure 2 is a schematic diagram of a high precision patterned LED structure based on transfer printing of an insulated langmuir monolayer in accordance with an embodiment of the present invention.

In the figure, 101 is a stamp used in the transfer printing technique;

102 is the glide barrier for controlling the sub-phase liquid surface area in langmuir monolayer preparation technology;

103 is the subphase solution used in the langmuir monolayer preparation technique:

104 is an insulating material used for preparing a leakage current barrier layer;

105 is a target substrate used in transfer printing techniques;

201 is a metal cathode of a patterned LED;

202 is an electron transport layer of a patterned LED;

203 is a patterned insulating layer prepared in a patterned LED using langmuir monolayer preparation techniques and transfer printing techniques;

204 is a light emitting unit in the patterned LED;

205 is a hole transport layer of a patterned LED;

206 is the hole injection layer of the patterned LED;

207 is the anode of the patterned LED;

208 is a substrate of patterned LEDs;

reference numeral 209 denotes a dc driving power source for the patterned LED.

Detailed Description

In order to make the features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail as follows:

example 1

The process for preparing the high-precision patterned LED leakage current blocking layer based on transfer printing of insulating langmuir monolayer provided in this example is as shown in fig. 1, and is performed as follows:

s11: dispersing an insulating material in an interface between the subphase solution 103 and the atmosphere;

s12: the area of the subphase liquid level is compressed by the slide barrier 102, so that the insulating material 104 forms a compact single layer which is arranged in order;

s13: selectively grasping the dense insulating monolayer formed in S12 using a high-precision patterned stamp 101;

s14: transferring the stamp together with the grasped insulating monolayer onto a target substrate 105;

s15: and stripping the seal from the insulating single layer to finish the transfer printing process.

Example 2

The structure of the high-precision patterned LED based on transfer printing of the insulated langmuir monolayer provided in this example is shown in fig. 2, and the preparation process is performed as follows:

s21: depositing the anode 207 of the LED on the substrate 208;

s22: depositing a hole injection layer 206 on the anode of the LED;

s23: depositing a hole transport layer 205 on the hole injection layer of the LED;

s24: transfer printing an insulating single layer based on Langmuir single layer preparation technology onto a hole transport layer of an LED with a high-precision patterned stamp;

s25: filling the patterned insulating monolayer 203 with an electroluminescent material to form a high-precision patterned light-emitting layer 204 of the LED;

s26: depositing an electron transport layer 202 over the high-precision patterned light emitting layer of the LED;

s27: a metal cathode 201 is deposited on the electron transport layer of the LED.

Then, a direct current driving power supply 209 of the LED can be connected between the cathode and the anode to completely realize the working function.

The present invention is not limited to the above preferred embodiments, and other various forms of highly precise patterned LED leakage current blocking layers based on transfer printing of insulating langmuir monolayers and methods for making the same can be derived by anyone skilled in the art from the teachings herein, and all equivalent changes and modifications that are within the scope of this invention are intended to be covered by this patent.