CN1566918A - Organic light-emitting diode electron microscope test piece and manufacturing method thereof - Google Patents

Abstract

An organic light emitting diode electron microscope test piece and a manufacturing method thereof. Firstly, an organic light emitting diode sample is provided, wherein the organic light emitting diode sample at least comprises a substrate, a first electrode layer, an organic layer and a second electrode layer. Then, a protective layer is formed on the surface of the sample. Then, the organic light emitting diode sample is cut to obtain an organic light emitting diode sample slice with a specific thickness, so as to increase the probability that organic material molecules of the organic layer are hit by an electron beam emitted by the transmission electron microscope, thereby generating diffraction imaging and obtaining an image of the test piece.

Description

Organic light-emitting diode electron microscope test piece and manufacturing method thereof

technical field

The invention relates to an electron microscope test piece, in particular to an organic light emitting diode electron microscope test piece and a manufacturing method thereof.

Background technique

With the advancement of material science, the microstructure has a great influence on the properties of the material itself. Therefore, in order to understand the properties of the material itself, it is necessary to have good microscopic analysis techniques and tools. General optical microscopes are limited by factors such as light wavelengths and aberrations, and their magnification is limited. Based on the demand for higher magnifications, new "microscopic" equipment is slowly developing, and electron microscopes are one of them. Electron-optical devices that identify microdomain structures, microstructures, chemical compositions, chemical bonds, and electron distributions from the signals generated by the interaction.

Electron microscope (Electron Microscope, EM) generally refers to the use of electromagnetic field deflection, focusing electrons and the principle of scattering generated by the interaction between electrons and matter to study the structure and fine structure of matter. One type of electron microscope, penetrating electron microscope A microscope (Transmission Electron Microscope, referred to as TEM) obtains a high-magnification image by passing electrons through the test piece and then through the lens magnification effect of the electromagnetic lens system. It has many applications in material science, such as: dislocation theory, point Defects, ion implantation, thin film structure, failure analysis of electronic components, etc., but the limit of its application is not the limitation of the resolution of the machine itself, but the difficulty of preparing the test piece. For TEM observation, the test piece needs Only with enough thin area can there be good electron penetration to obtain sufficient resolution.

The basic structure of an organic light emitting diode (Organic Light Emitting Diode, OLED), please refer to Figure 1, including: a metal cathode 12, a transparent anode 14, a transparent substrate 16 and an organic layer 10, wherein The organic material further includes an electron transport layer 10 , a light emitting layer 102 and a hole transport layer 103 . The light-emitting principle of the organic light-emitting diode is to apply a voltage to the above-mentioned metal cathode 12 and transparent anode 14 to drive electrons and holes to recombine in the organic layer 10. The energy released by this recombination will excite organic material molecules, and then A luminescent phenomenon occurs, and then radiates out through the transparent substrate 16 to become a self-illuminating display component. In the conventional technology, the control of the thickness of each organic material in the organic layer 10 can only be controlled by the quartz oscillator of the on-line machine, not by actual measurement, so there is no way to accurately control the thickness of each layer.

When intending to observe the structure of each organic material layer in the organic layer 10 with a transmission electron microscope (TEM), its test piece is made under the assistance of a focused ion beam (Focus Ion Beam), and a test piece thickness less than Films below 0.1 micron, and in the traditional concept, as long as the test piece can be ground thinner, the resolution will be better, but for organic light-emitting diodes, when the thickness of the test piece is less than 0.1 micron, as shown in Figure 2 As shown, the layers and structures of the organic materials in the organic layer 10 cannot be distinguished by the transmission electron microscope. Driven by the traditional concept, the test piece will only be thinned again, and the result still cannot be obtained from the transmission electron microscope. The microscope distinguishes the layers and structures of organic materials. In view of this, the present invention proposes a method for making an OLED electron microscope test piece, so that the structure and level of each organic material in the organic layer can be clearly distinguished under the electron microscope.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for making an electron microscope test piece, in particular to provide an organic light-emitting diode electron microscope test piece and its production method, so that a clear test piece image can be obtained when the test piece is observed, Contributes to the structural analysis of organic materials.

The organic light-emitting diode electron microscope test piece and its manufacturing method provided by the present invention are realized by the following technical solutions.

A method for making an organic light-emitting diode electron microscope test piece, which is used for the observation of the electron microscope. The electron beam emitted by the electron microscope passes through the test piece to produce penetration and diffraction phenomena, and the image of the test piece is obtained. is to include at least the following steps:

An organic light emitting diode sample is provided, wherein the organic light emitting diode sample at least includes a substrate, a first electrode layer, an organic layer and a second electrode layer, the first electrode layer is located on the substrate, and the organic layer is On the first electrode layer, the second electrode layer is on the organic layer;

forming a protective layer on the surface of the sample; and

A cutting procedure is performed on the OLED sample to obtain thin slices of the OLED sample.

The method for making the organic light-emitting diode electron microscope specimen is characterized in that: the thickness of the thin slice is between 0.2 microns and 0.3 microns.

The method for making the organic light-emitting diode electron microscope test piece is characterized in that: the above-mentioned cutting procedure is carried out with focused ion beams.

The method for making the organic light emitting diode electron microscope test piece is characterized in that: the thickness of the protective layer is between 2 microns and 3 microns.

The manufacturing method of the organic light emitting diode electron microscope test piece is characterized in that: the above-mentioned protective layer is platinum.

The manufacturing method of the organic light emitting diode electron microscope test piece is characterized in that: the above-mentioned protective layer is tungsten.

The method for making the organic light-emitting diode electron microscope specimen is characterized in that: the procedure of cutting the sample with the focused ion beam includes a procedure of rough cutting.

The method for making the organic light-emitting diode electron microscope test piece is characterized in that it further includes a fine-cutting procedure.

The method for making the organic light-emitting diode electron microscope test piece is characterized in that it further includes a precise cutting procedure.

The method for making the organic light-emitting diode electron microscope test piece is characterized in that: the above-mentioned electron microscope is a transmission electron microscope.

The present invention also provides an organic light-emitting diode electron microscope test piece used in the above method, which is used for the observation of the electron microscope. The electron beam emitted by the electron microscope passes through the test piece to produce penetration and diffraction phenomena, and obtains The image of the test strip is characterized by at least including:

a substrate;

A first electrode layer is located on the substrate;

an organic layer is located on the first electrode layer;

a second electrode layer is located on the organic layer; and

a protection layer is fabricated on the second electrode layer;

The thickness of the test piece is between 0.2 micron and 0.3 micron, which is used to increase the probability that the organic material molecules in the organic layer are hit by the electron beam, so as to produce diffraction imaging.

The characteristic of the organic light emitting diode electron microscope test piece is that the protective layer is formed on the second electrode layer by focusing ion beams.

The OLED electron microscope test piece is characterized in that: the thickness of the protective layer is between 2 microns and 3 microns.

The organic light-emitting diode electron microscope test piece is characterized in that: the above-mentioned protective layer is platinum.

The organic light-emitting diode electron microscope test piece is characterized in that: the above-mentioned protective layer is tungsten.

The organic light emitting diode electron microscope test piece is characterized in that: the above-mentioned electron microscope is a transmission electron microscope.

The invention provides a method for making an organic light-emitting diode electron microscope test piece, which can be used for the observation of the electron microscope. The electron beam emitted by the transmission electron microscope passes through the test piece to produce penetration and diffraction phenomena, and the test piece is obtained. image of the film. Firstly, an organic light emitting diode sample is provided, wherein the organic light emitting diode sample sequentially includes a substrate, a first electrode layer, an organic layer and a second electrode layer. Next, a metal protective layer is formed on the surface of the sample. Subsequently, the cutting process of the focused ion beam is performed on the organic light emitting diode sample, wherein the cutting process includes the steps of rough cutting, fine cutting and fine cutting in order to obtain thin slices with a thickness between 0.2 microns and 0.3 microns, In this way, the probability of the organic material molecules in the organic layer being hit by the electron beam can be increased, and diffraction imaging can be produced.

The preparation method of the test piece of the organic light-emitting diode electron microscope of the present invention has the following advantages:

(1) Through the design of the present invention, the hierarchical structures of the organic materials in the organic light-emitting diode (OLED) can be clearly observed by a transmission electron microscope.

(2) When the hierarchical structure of the organic material can be clearly identified, the thickness of each layer can be clearly confirmed, instead of relying on the adjustment of other objective parameters, such as: the time of evaporation of the organic material, to infer the organic material layer actual thickness.

(3) After obtaining the accurate actual thickness value of the organic material layer, it will help the analysis on the structure, and because the organic light emitting diode is a self-luminous component, wherein the organic material layer is more directly related to the generation of the light source, through the method of the present invention design, the thickness of each organic layer can be precisely adjusted, and then the optimal luminous effect can be obtained.

With the following detailed description combined with the accompanying drawings, the above contents and many advantages of the present invention will be easily understood.

Description of drawings

FIG. 1 is a basic structural diagram of an organic light emitting diode.

Fig. 2 is a cross-sectional observation view of an organic light emitting diode obtained according to the prior art.

FIG. 3 is a flowchart of a method for manufacturing an OLED electron microscope specimen according to a preferred embodiment of the present invention.

FIG. 4 is a schematic diagram of cutting an OLED sample according to an embodiment of the present invention. as well as

FIG. 5 is a cross-sectional observation view of an organic light emitting diode obtained according to an embodiment of the present invention.

Detailed ways

The invention provides a method for manufacturing an organic light-emitting diode electron microscope test piece. In the present invention, by controlling the thickness of the test piece, the electron beam emitted by the transmission electron microscope will produce penetration and diffraction phenomena when passing through the test piece, and then obtain the image of the test piece to be observed, so that the organic light emitting diode The structure of each layer of the organic material can be clearly identified under the electron microscope, which will be of great help to the analysis and research of the structure of the organic light emitting diode. A preferred embodiment is listed below to illustrate the present invention, but those skilled in the art know that this is only an example, not intended to limit the invention itself. The content of this preferred embodiment is described in detail as follows.

As shown in FIG. 3 , it is a flowchart of a method for manufacturing an OLED electron microscope specimen according to a preferred embodiment of the present invention. As shown in step 201, an organic light emitting diode sample is firstly provided, wherein the organic light emitting diode sample includes a substrate, a first electrode layer, an organic layer and a second electrode layer, and the organic layer further includes an electron transport layer, A light-emitting layer and a hole-transporting layer. However, the structure of each layer in the above-mentioned organic layer is only an example and is not intended to limit the scope of the present invention.

Next, as shown in step 202 , a protective layer is formed on the surface of the OLED sample. This protective layer uses metal materials such as platinum (Pt) or tungsten (W) to focus the ion beam (Focus Ion Beam, FIB) on the surface of the organic light-emitting diode sample, forming a metal thickness between 2 microns and 3 microns The function of the thin film is: on the one hand, it can provide the stability of the sample structure, avoiding the collapse of the sample structure during the high-energy cutting step in the later stage; on the other hand, it can also be used as a label to facilitate observation.

Next, as described in step 203, the OLED sample is cut into thin slices with a predetermined thickness. Please also refer to FIG. 4 , which is a schematic diagram of cutting an OLED sample according to an embodiment of the present invention. First, on one side of the organic light emitting diode sample 20 coated with a protective layer, use a focused ion beam to first perform coarse milling with a high current (coarse milling), then use a focused ion beam with a medium current to perform fine cutting (intermediate milling), and finally Then perform a fine milling procedure with a small current. Then, on the other side of the OLED sample 20 coated with the protective layer, the steps of rough cutting, fine cutting, and fine cutting are sequentially performed to form thin slices with a thickness between 0.2 microns and 0.3 microns. The cutting holes 2031 , 2032 , and 2033 shown in the figure are the cutting holes formed through the steps of rough cutting, fine cutting and fine cutting respectively.

Next, as shown in step 204, the OLED sheet is removed. Please refer to FIG. 4 at the same time, the two ends of the organic light emitting diode sample 20 are connected to the part of the sample body, and the focused ion beam is used to separate them, so that the production of the electron microscope test piece is completed. When observing the cross-section of the test piece, the organic light emitting diode slice is first placed on a carbon film, and then the carbon film with the organic light emitting diode slice is placed on a copper grid to observe the test piece.

As shown in Figure 5, it is a cross-sectional observation view of a test piece made according to an embodiment of the present invention. It can be seen from the figure that each layer structure in the organic layer 10 includes an electron transport layer 103, a light-emitting layer 102, and a hole transport layer. 101. The present invention controls the thickness of the test piece (between 0.2 microns and 0.3 microns), so that when the organic light-emitting diode test piece is observed by a transmission electron microscope, the organic material molecules in the organic layer are emitted by the electron microscope The high probability of electron beam hitting can produce diffraction imaging, so that the structure of each level can be clearly identified through the electron microscope.

Although the present invention has been described above with preferred examples, it is not intended to limit the spirit and entities of the present invention to the above-mentioned examples. Therefore, modifications made without departing from the spirit and scope of the present invention should be included in the scope of the claims.

Claims (16)

1, the method for making of a kind of Organic Light Emitting Diode electron microscope test piece, be used for the observation of electron microscope, pass this test piece generation by this electron microscope ejected electron bundle and penetrate and the diffraction phenomenon, obtain the image of this test piece, it is characterized in that comprising at least the following step:

One Organic Light Emitting Diode sample is provided, wherein this Organic Light Emitting Diode sample comprises a substrate, one first electrode layer, an organic layer and a second electrode lay at least, this first electrode layer is to be positioned on this substrate, this organic layer is to be positioned on this first electrode layer, and this second electrode lay is to be positioned on this organic layer;

Form the surface of a protective seam in this sample; And

This Organic Light Emitting Diode sample is carried out a cutting program, obtain the thin slice of this Organic Light Emitting Diode sample.

2, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece is characterized in that: the thickness of above-mentioned thin slice is between 0.2 micron to 0.3 micron.

3, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece is characterized in that: above-mentioned cutting process is to carry out with focused ion beam.

4, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece is characterized in that: the thickness of above-mentioned protective seam is between 2 microns to 3 microns.

5, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece, it is characterized in that: above-mentioned protective seam is a platinum.

6, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece, it is characterized in that: above-mentioned protective seam is a tungsten.

7, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece is characterized in that: above-mentioned with focused ion beam this sample to be carried out cutting process be the program that comprises a rough lumber.

8, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece is characterized in that: more comprise the program of frittering.

9, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece is characterized in that: more comprise the program that an essence is cut.

10, the method for making of Organic Light Emitting Diode electron microscope according to claim 1 test piece, it is characterized in that: above-mentioned electron microscope is a transmission electron microscope.

11, a kind of Organic Light Emitting Diode electron microscope test piece is used for the usefulness of the observation of electron microscope, passes this test piece by this electron microscope ejected electron bundle and produces and penetrate and the diffraction phenomenon, obtains the image of this test piece, it is characterized in that comprising at least:

One substrate;

One first electrode layer is to be positioned on this substrate;

One organic layer is to be positioned on this first electrode layer;

One the second electrode lay is to be positioned on this organic layer; And

One protective seam is to be made on this second electrode lay;

Wherein the thickness of this test piece is between 0.2 micron to 0.3 micron, and the probability in order to the organic material molecule that increases this organic layer is got to by electron beam is produced the diffraction imaging.

12, Organic Light Emitting Diode electron microscope according to claim 11 test piece is characterized in that: above-mentioned protective seam is to be formed on this second electrode lay with focused ion beam.

13, Organic Light Emitting Diode electron microscope according to claim 11 test piece is characterized in that: the thickness of above-mentioned protective seam is between 2 microns to 3 microns.

14, Organic Light Emitting Diode electron microscope according to claim 11 test piece is characterized in that: above-mentioned protective seam is a platinum.

15, Organic Light Emitting Diode electron microscope according to claim 11 test piece is characterized in that: above-mentioned protective seam is a tungsten.

16, Organic Light Emitting Diode electron microscope according to claim 11 test piece is characterized in that: above-mentioned electron microscope is to be transmission electron microscope.

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