CN111146367A - Preparation method of light extraction film with micro-nano composite structure - Google Patents
Preparation method of light extraction film with micro-nano composite structure Download PDFInfo
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- CN111146367A CN111146367A CN202010062209.6A CN202010062209A CN111146367A CN 111146367 A CN111146367 A CN 111146367A CN 202010062209 A CN202010062209 A CN 202010062209A CN 111146367 A CN111146367 A CN 111146367A
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/80—Constructional details
- H10K50/85—Arrangements for extracting light from the devices
Abstract
The invention relates to a preparation method of a light extraction film with a micro-nano composite structure, which comprises the following steps: step S1: preparing a PDMS template with an ordered micron structure by adopting a soft printing method; step S2: stretching the PDMS template with the ordered microstructure, carrying out plasma treatment, obtaining nano patterns with different shapes and sizes on the PDMS template with the microstructure, and forming PDMS micro-nano composite patterns with the opposite micro-nano composite structure to the required micro-nano composite structure; step S3: and transferring the PDMS micro-nano composite pattern to a required polymer to obtain the light extraction film. The invention has high manufacturing efficiency and low cost, and the prepared light extraction film is nested in the disordered nano structure in the ordered micro structure pattern, can avoid the light loss of the device substrate and the air interface, and has stronger light extraction effect while not changing the visual angle characteristic of the OLED device.
Description
Technical Field
The invention relates to the technical field of photoelectric display, in particular to a preparation method of a light extraction film with a micro-nano composite structure.
Background
Organic Light Emitting Diodes (OLEDs) are widely used in displays of mobile phones and televisions, however, external quantum efficiency of the OLEDs is about 20% due to losses generated by a surface plasmon resonance mode at a metal-organic interface, a waveguide mode in an Indium Tin Oxide (ITO)/organic layer, a substrate mode in a glass substrate, and the like.
Since the refractive index between the ITO/glass interface and the glass/air interface is small, the optical loss in the substrate mode is larger than that in the waveguide mode, and thus, adding a light extraction layer at the glass/air interface can greatly increase the light emitting efficiency of the OLED.
Conventional single periodic microstructure light extraction films tend to alter the spectral characteristics and angular distribution of the device.
Disclosure of Invention
In view of the above, the present invention provides a method for preparing a light extraction film with a micro-nano composite structure, which can avoid light loss at an interface between a device substrate and air, and has a strong light extraction effect without changing a viewing angle characteristic of an OLED device.
The invention is realized by adopting the following scheme: a preparation method of a light extraction film with a micro-nano composite structure comprises a substrate, a periodic microstructure applied on the substrate, and a nano structure applied on the microstructure; the preparation of the light extraction film comprises the following steps:
step S1: preparing a PDMS template with an ordered micron structure by adopting a soft printing method;
step S2: stretching the PDMS template with the ordered microstructure in a single direction or multiple directions simultaneously, carrying out plasma treatment, and obtaining nano patterns with different shapes and sizes on the PDMS template with the microstructure to form PDMS micro-nano composite patterns; the nano-structure pattern is controlled by regulating and controlling the stretching direction, so that the extraction efficiency of light in different directions is controlled;
step S3: transferring the PDMS micro-nano composite pattern to a required polymer to form a micro-nano composite pattern with a structure opposite to that of the required micro-nano composite structure;
step S4: and (4) taking the micro-nano composite pattern which is obtained in the step (S3) and is opposite to the required micro-nano composite structure as a template, and copying the light extraction film with the required micro-nano composite structure once or for multiple times so as to improve the preparation efficiency.
Further, step S1 specifically includes the following steps:
step S11: preparing a micron pattern on a clean substrate, annealing the micron pattern, improving the bonding force between the pattern and the substrate, and forming a micron pattern master mask;
step S12: performing surface modification on the micron pattern master mask by adopting trimethylchlorosilane;
step S13: uniformly mixing polydimethylsiloxane monomers and a cross-linking agent according to a preset proportion by adopting a soft printing method, vacuumizing to remove bubbles, uniformly spin-coating on a micro-pattern mother plate, standing, heating for curing, and stripping to obtain a polydimethylsiloxane micro-structure opposite to the micro-pattern mother plate, namely the PDMS template with the ordered micro-structure.
Further, step S3 specifically includes the following steps:
step S31: placing the PDMS template with the PDMS micro-nano composite pattern obtained in the step S3 in vacuum to remove gas in the polydimethylsiloxane, and forming negative pressure;
step S32: uniformly coating ultraviolet curing glue on the substrate, placing the PDMS template with the negative pressure treated in the step S31 on the ultraviolet curing glue on the side with the pattern, standing for a period of time under the action of the negative pressure and gravity, and stripping the PDMS template after ultraviolet exposure to obtain the UV glue micro-nano composite pattern with the opposite micro-nano composite structure to the required micro-nano composite structure.
Further, in step S4, the replicating the required micro-nano composite structure light extraction film specifically includes the following steps:
step S41: uniformly mixing PDMS monomers and a cross-linking agent according to a preset proportion, and vacuumizing to remove bubbles;
step S42: and (4) uniformly spin-coating the mixture of the PDMS monomer and the cross-linking agent on the micrometer pattern which is obtained in the step S3 and is opposite to the required micro-nano composite structure, standing for a period of time, blowing off surface bubbles with gas, heating and curing, and stripping to obtain the PDMS micro-nano composite structure light extraction film.
Further, in step S11, the micro pattern is prepared by a method including, but not limited to, photoresist melting, laser etching, screen printing, inkjet printing, or a combination thereof, and the micro pattern is periodically one-dimensional or two-dimensional.
Further, in step S13, the ratio of the polydimethylsiloxane monomer to the cross-linking agent is 100:1 to 1: 1.
Further, in step S2, the stretching degree is 0% to 500%.
Further, in step S2, the reactive ion etching power of the plasma treatment is 50-250W, the reactive ion etching time is 40-240S, the reactive ion etching flow rate is 10-60 sccm, the reactive ion etching pressure is 1-10 pa, and the reactive ion etching gas includes, but is not limited to, oxygen, argon or a mixed gas.
Compared with the prior art, the invention has the following beneficial effects:
1. the light extraction film prepared by the method is embedded with the disordered nano structure in the ordered micro structure pattern, can avoid the light loss of the device substrate and the air interface, and has stronger light extraction effect while the visual angle characteristic of the OLED device is not changed.
2. The invention controls the nanostructure pattern by regulating the stretching direction, thereby controlling the extraction efficiency of light in different directions.
3. The invention takes the obtained micro-nano composite pattern with the opposite structure to the required micro-nano composite structure as a template, and can obtain the required light extraction film by adopting a simple copying method subsequently, thereby having high manufacturing efficiency and low cost.
Drawings
FIG. 1 shows a process for forming a photoresist master in accordance with an embodiment of the present invention. Wherein (a) is a photoresist spin coating process, (b) is a photoresist patterning process, and (c) is a photoresist micron-scale patterning process.
Fig. 2 is a process of preparing a PDMS soft mold with a master in an embodiment of the present invention. The method comprises the following steps of (a) a process for filling a photoresist master plate by PDMS spin coating, (b) a process for curing and demolding the PDMS, (c) a process for etching reactive ions after PDMS is prestretched, and (d) a schematic diagram for forming a micro-nano composite structure by the PDMS.
Fig. 3 is a process flow of imprinting and preparing a micro-nano composite structure according to an embodiment of the invention. The method comprises the following steps of (a) carrying out ultraviolet curing glue spin coating, (b) carrying out a process of impressing ultraviolet curing glue to form a micro-nano composite structure, and (c) carrying out ultraviolet curing glue demoulding.
Fig. 4 is a scanning electron microscope image of the micro-nano composite structure in the embodiment of the invention.
In the figure, 1 is a substrate, 2 is photoresist, 3 is PDMS, 4 is reactive ion etching gas, 5 is ultraviolet curing glue, and 6 is a ultraviolet curing lamp.
Detailed Description
The invention is further explained below with reference to the drawings and the embodiments.
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
As shown in fig. 1 to fig. 3, the present embodiment provides a method for preparing a light extraction film with a micro-nano composite structure, where the light extraction film includes a substrate, a periodic microstructure applied on the substrate, and a nanostructure applied on the microstructure; the preparation of the light extraction film comprises the following steps:
step S1: preparing a PDMS template with an ordered micron structure by adopting a soft printing method;
step S11: as shown in fig. 1, the surface of a substrate is ultrasonically cleaned by acetone, ethanol and deionized water, nitrogen is used for blow-drying, a micron pattern is prepared on a clean substrate, 90-degree annealing is carried out on the micron pattern, the bonding force between the pattern and the substrate is improved, and a micron pattern mother plate is formed;
step S12: as shown in (a) and (b) in fig. 2, performing surface modification on the micro pattern master plate by using trimethylchlorosilane;
step S13: and (2) coating PDMS on the mother plate in a spin mode by adopting a soft printing method, uniformly mixing polydimethylsiloxane monomers and a cross-linking agent in a ratio of 10:1, vacuumizing to remove bubbles, uniformly coating the PDMS on the micro-pattern mother plate in a spin mode at 500rpm for 60s, standing for 5min, heating and curing for 2h at 80 ℃, and stripping to obtain a polydimethylsiloxane micro-structure opposite to the micro-pattern mother plate, namely the PDMS template with the ordered micro-structure.
Step S2: as shown in (c) and (d) of fig. 2, the PDMS template with the ordered microstructure is stretched in a single direction or in multiple directions simultaneously, and plasma treatment is performed to obtain nano patterns with different shapes and sizes on the PDMS template with the microstructure, so as to form a PDMS micro-nano composite pattern with a structure opposite to the required micro-nano composite structure; the nano-structure pattern is controlled by regulating and controlling the stretching direction, so that the extraction efficiency of light in different directions is controlled;
step S3: transferring the PDMS micro-nano composite pattern to a required polymer to form a micro-nano composite pattern with a structure opposite to that of the required micro-nano composite structure;
step S4: and (4) taking the micro-nano composite pattern which is obtained in the step (S3) and is opposite to the required micro-nano composite structure as a template, and copying the light extraction film with the required micro-nano composite structure once or for multiple times so as to improve the preparation efficiency.
In this embodiment, step S3 specifically includes the following steps:
step S31: placing the PDMS template with the PDMS micro-nano composite pattern obtained in the step S3 in vacuum to remove gas in the polydimethylsiloxane, and forming negative pressure;
step S32: as shown in fig. 3, spin-coating an ultraviolet curing adhesive on a glass substrate at a rotating speed of 3000rpm for 40s, placing the patterned surface on the ultraviolet curing adhesive, standing for 5-10min under the action of polydimethylsiloxane negative pressure and gravity, exposing under an ultraviolet lamp for 20min, and stripping the polydimethylsiloxane to obtain the UV adhesive micro-nano composite pattern with the opposite micro-nano composite structure.
In step S4, the method for replicating the required micro-nano composite structure light extraction film specifically includes the following steps:
step S41: uniformly mixing PDMS monomers and a cross-linking agent according to a preset proportion, and vacuumizing to remove bubbles;
step S42: and (4) uniformly spin-coating the mixture of the PDMS monomer and the cross-linking agent on the micrometer pattern which is obtained in the step S3 and is opposite to the required micro-nano composite structure, standing for a period of time, blowing off surface bubbles with gas, heating and curing, and stripping to obtain the PDMS micro-nano composite structure light extraction film.
In this embodiment, in step S11, the micro pattern is prepared by a method including, but not limited to, photoresist melting, laser etching, screen printing, inkjet printing, or a combination thereof, and the micro pattern is periodically one-dimensional or two-dimensional.
In this embodiment, in step S13, the ratio of the polydimethylsiloxane monomer to the cross-linking agent is 100:1 to 1: 1.
In the present embodiment, in step S2, the stretching degree is 0% to 500%.
In this embodiment, in step S2, the reactive ion etching power of the plasma processing is 50-250W, the reactive ion etching time is 40-240S, the reactive ion etching flow rate is 10-60 sccm, the reactive ion etching pressure is 1-10 pa, and the reactive ion etching gas includes, but is not limited to, oxygen, argon, or a mixed gas.
Preferably, the light extraction film prepared in this embodiment may be disposed inside the light emitting device or disposed outside the light emitting device by using the refractive index matching fluid. Fig. 4 is a scanning electron microscope image of the micro-nano composite structure light extraction film prepared by the method of the embodiment.
The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.
Claims (8)
1. A preparation method of a light extraction film with a micro-nano composite structure is characterized in that the light extraction film comprises a substrate, a periodic microstructure applied on the substrate and a nano structure applied on the microstructure; the preparation of the light extraction film comprises the following steps:
step S1: preparing a PDMS template with an ordered micron structure by adopting a soft printing method;
step S2: the method comprises the following steps of simultaneously stretching a PDMS template with an ordered microstructure in a single direction or multiple directions, carrying out plasma treatment, obtaining nano patterns with different shapes and sizes on the PDMS template with the microstructure to form PDMS micro-nano composite patterns, and controlling the nano-structure patterns by regulating and controlling the stretching direction so as to control the extraction efficiency of light in different directions;
step S3: transferring the PDMS micro-nano composite pattern to a required polymer to form a micro-nano composite pattern with a structure opposite to that of the required micro-nano composite structure;
step S4: and (4) taking the micro-nano composite pattern which is obtained in the step (S3) and is opposite to the required micro-nano composite structure as a template, and copying the light extraction film with the required micro-nano composite structure once or for multiple times so as to improve the preparation efficiency.
2. The preparation method of the light extraction film with the micro-nano composite structure according to claim 1, wherein the step S1 specifically comprises the following steps:
step S11: preparing a micron pattern on a clean substrate, annealing the micron pattern, improving the bonding force between the pattern and the substrate, and forming a micron pattern master mask;
step S12: performing surface modification on the micron pattern master mask by adopting trimethylchlorosilane;
step S13: uniformly mixing polydimethylsiloxane monomers and a cross-linking agent according to a preset proportion by adopting a soft printing method, vacuumizing to remove bubbles, uniformly spin-coating on a micro-pattern mother plate, standing, heating for curing, and stripping to obtain a polydimethylsiloxane micro-structure opposite to the micro-pattern mother plate, namely the PDMS template with the ordered micro-structure.
3. The preparation method of the light extraction film with the micro-nano composite structure according to claim 1, wherein the step S3 specifically comprises the following steps:
step S31: placing the PDMS template with the PDMS micro-nano composite pattern obtained in the step S3 in vacuum to remove gas in the polydimethylsiloxane, and forming negative pressure;
step S32: uniformly coating ultraviolet curing glue on the substrate, placing the PDMS template with the negative pressure treated in the step S31 on the ultraviolet curing glue on the side with the pattern, standing for a period of time under the action of the negative pressure and gravity, and stripping the PDMS template after ultraviolet exposure to obtain the UV glue micro-nano composite pattern with the opposite micro-nano composite structure to the required micro-nano composite structure.
4. The method for preparing a light extraction film with a micro-nano composite structure according to claim 1, wherein in step S4, the replication of the light extraction film with the required micro-nano composite structure specifically comprises the following steps:
step S41: uniformly mixing PDMS monomers and a cross-linking agent according to a preset proportion, and vacuumizing to remove bubbles;
step S42: and (4) uniformly spin-coating the mixture of the PDMS monomer and the cross-linking agent on the micrometer pattern which is obtained in the step S3 and is opposite to the required micro-nano composite structure, standing for a period of time, blowing off surface bubbles with gas, heating and curing, and stripping to obtain the PDMS micro-nano composite structure light extraction film.
5. The method for preparing a light extraction film with a micro-nano composite structure according to claim 2, wherein in step S11, the micro pattern is prepared by a method including but not limited to photoresist melting, laser etching, screen printing, inkjet printing, or a combination thereof, and the micro pattern periodicity is one-dimensional or two-dimensional.
6. The preparation method of the light extraction film with the micro-nano composite structure according to claim 2, wherein in step S13, the ratio of the polydimethylsiloxane monomer to the cross-linking agent is 100: 1-1: 1.
7. The method for preparing a light extraction film with a micro-nano composite structure according to claim 1, wherein in the step S2, the stretching degree is 0% -500%.
8. The method for preparing a light extraction film with a micro-nano composite structure according to claim 1, wherein in step S2, the reactive ion etching power of the plasma treatment is 50-250W, the reactive ion etching time is 40-240S, the reactive ion etching flow rate is 10-60 sccm, the reactive ion etching pressure is 1-10 pa, and the reactive ion etching gas includes but is not limited to oxygen, argon or mixed gas.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112768621A (en) * | 2021-01-27 | 2021-05-07 | 福州大学 | Integrated cycle micro-concave mirror composite light extraction structure |
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