阅读说明：本技术 一种利用等离子体刻蚀测量聚合物亚层光电子能谱的方法 (Method for measuring photoelectron spectrum of polymer sublayer by plasma etching ) 是由 卜腊菊 翟晨阳 鲁广昊 于 2020-05-12 设计创作，主要内容包括：本发明公开了一种利用等离子体刻蚀测量聚合物亚层光电子能谱的方法,包括以下步骤：(1)将两块ITO玻璃衬底清洗,用氮气吹干,经紫外-臭氧处理后,置于正辛基三氯硅烷溶液中修饰；(2)在经修饰的两块ITO玻璃衬底上制备聚合物薄膜,分别标记为薄膜1和薄膜2；(3)利用紫外光电子能谱仪检测聚合物薄膜1的紫外光电子能谱,利用低气压(20帕斯卡)氧等离子体刻蚀聚合物薄膜2并检测其紫外光电子能谱。本发明将低压氧等离子体刻蚀技术与紫外光电子能谱法相结合,检测聚合物半导体薄膜不同深度位置处的紫外光电子能谱,即亚层光电子能谱,并获得能级分布,有利于探索聚合物半导体薄膜性质与光电器件性能间的关系,在薄膜分析领域有广泛应用前景。(The invention discloses a method for measuring a polymer sub-layer photoelectron spectrum by utilizing plasma etching, which comprises the following steps of: (1) cleaning two ITO glass substrates, drying the two ITO glass substrates by using nitrogen, performing ultraviolet-ozone treatment, and then placing the two ITO glass substrates in a n-octyl trichlorosilane solution for modification; (2) preparing polymer films on the two modified ITO glass substrates, wherein the polymer films are respectively marked as a film 1 and a film 2; (3) and detecting the ultraviolet electron energy spectrum of the polymer film 1 by using an ultraviolet photoelectron spectrometer, etching the polymer film 2 by using oxygen plasma with low air pressure (20 pascals), and detecting the ultraviolet electron energy spectrum. The invention combines the low-pressure oxygen plasma etching technology with the ultraviolet photoelectron spectroscopy to detect the ultraviolet photoelectron spectroscopy at different depth positions of the polymer semiconductor film, namely the sub-layer photoelectron spectroscopy, and obtains energy level distribution, thereby being beneficial to exploring the relationship between the properties of the polymer semiconductor film and the performances of photoelectric devices and having wide application prospect in the field of film analysis.)

1. A method for measuring photoelectron spectroscopy of a polymer sublayer by plasma etching, comprising the steps of:

(1) cleaning two ITO glass substrates, drying the two ITO glass substrates by using nitrogen, performing ultraviolet-ozone treatment, and then placing the two ITO glass substrates in a n-octyl trichlorosilane solution for modification;

(2) preparing polymer films on the two modified ITO glass substrates, wherein the polymer films are respectively marked as a film 1 and a film 2, and the thicknesses of the polymer films are about 50 nanometers;

(3) detecting the ultraviolet electron energy spectrum of the polymer film 1 by using an ultraviolet photoelectron spectrometer; and etching the film 2 by using the oxygen plasma, reducing the thickness of the film 2, detecting an ultraviolet electron energy spectrum of the film, and detecting the information of a few nanometers on the surface of the film by using the ultraviolet electron energy spectrum.

2. The method according to claim 1, wherein the ITO glass substrate in step (1) is modified by adding n-octyltrichlorosilane to toluene to prepare a solution with a concentration of 3.75% o, immersing the ITO glass substrate in the solution for standing for 2 hours, and controlling the temperature to 85 ℃.

3. The method for measuring photoelectron spectroscopy of a polymer sublayer by using plasma etching as claimed in claim 1, wherein in step (2), the polymer film material is soluble polythiophene, and the substance films 1 and 2 are obtained under the same preparation condition without significant difference.

4. The method for measuring photoelectron spectroscopy of a polymer sublayer by plasma etching as claimed in claim 1, wherein in the step (3), the discharge power of the oxygen plasma is 200 w, the gas pressure is 20 pa, the etching speed is 1 nm/s, and the etching time is 12 s.

Technical Field

The invention belongs to the technical field of material photoelectron spectroscopy analysis, and particularly relates to a method for measuring polymer sublayer photoelectron spectroscopy by plasma etching.

Background

The polymer semiconductor film has the characteristics of flexibility, low cost, solution processability and the like, and has wide application prospects 1 and 2 in the field of next-generation optoelectronic devices. The reasonable distribution of the energy level of the polymer semiconductor has great influence on the improvement of the performance of the optoelectronic device. The energy level distribution of the semiconductor can be detected by a number of techniques including cyclic voltammetry 3, kelvin probe force microscopy 4, and photoelectron spectroscopy 5. Among them, the most commonly used technique is ultraviolet photoelectron spectroscopy, which is mainly used for detecting surface information of a thin film. However, for polymer semiconductors, material properties change along the depth of the film as a result of changes in the material structure at the air/film interface and the film/substrate interface during solution processing. Therefore, in order to understand the relationship between the energy level distribution of the polymer semiconductor and the performance of the optoelectronic device, it is necessary to grasp the energy level variation in the depth direction of the film. Currently, researchers combine argon cluster ion etching technology with ultraviolet electron spectroscopy to obtain energy level distribution in the depth direction of a polymer semiconductor film processed by a solution, and apply the energy level distribution to the field of organic solar cells 6. However, the argon cluster ion etching technique is costly and not suitable for repeated test applications.

Reference documents:

1. yellow fly; thin aspiration of cortex et radix Polygalae; gunn waiting; red donation; king luck; horsetail atractylodes rhizome; waiting for the sword glow; a Huwenping; for making an upright; the product is in good condition; a queen tree; plum shaking; handsome aspiration is carried out; plum never boat; cao-variation, research on photoelectric polymer materials has progressed to 2019, 50, (10), 988-1046.

2.Li,D.D.；Lai,W.-Y.；Zhang,Y.-Z.；Huang,W.,Printable TransparentConductive Films for Flexible Electronics.Adv.Mater.2018,30,(10),1704738.

3.Qiu,B.；Chen,S.；Li,H.；Luo,Z.；Yao,J.；Sun,C.；Li,X.；Xue,L.；Zhang,Z.-G.；Yang,C.；Li,Y.,A Simple Approach to Prepare Chlorinated Polymer Donors withLow-Lying HOMO Level for High Performance Polymer Solar Cells.Chemistry ofMaterials,2019,31,(17),6558-6567.

4.Sadewasser,S.；Thilo,G.,Kelvin probe force microscopy.Springer:Berlin,2012.

5.Ueno,N.；Kera,S.；Sakamoto,K.；Okudaira,K.K.,Energy band and electron-vibration coupling in organic thin films:photoelectron spectroscopy as apowerful tool for studying the charge transport.Applied Physics A,2008,92,(3),495-504.

6.Lami,V.；Weu，A.；Zhang,J.；Chen,Y.；Fei,Z.；Heeney,M.；Friend,R.H.；Vaynzof,Y.，Visualizing the Vertical Energetic Landscape in OrganicPhotovoltaics.Joule,3,(10),2513-2534.

Disclosure of Invention

The invention aims to provide a method for measuring a polymer sub-layer photoelectron spectrum by utilizing plasma etching, which is used for measuring the energy level distribution of a polymer semiconductor film in the depth direction.

The invention is realized by the following technical scheme:

a method for measuring photoelectron spectroscopy of a polymer sublayer using plasma etching, comprising the steps of:

(1) cleaning two ITO glass substrates, drying the two ITO glass substrates by using nitrogen, performing ultraviolet-ozone treatment, and then placing the two ITO glass substrates in a n-octyl trichlorosilane solution for modification;

(2) preparing polymer films on the two modified ITO glass substrates, wherein the polymer films are respectively marked as a film 1 and a film 2, and the thicknesses of the polymer films are about 50 nanometers;

(3) detecting the ultraviolet electron energy spectrum of the polymer film 1 by using an ultraviolet photoelectron spectrometer; and etching the film 2 by using the oxygen plasma, reducing the thickness of the film 2, detecting an ultraviolet electron energy spectrum of the film, and detecting the information of a few nanometers on the surface of the film by using the ultraviolet electron energy spectrum.

The further improvement of the invention is that the modification method of the ITO glass substrate in the step (1) is that n-octyl trichlorosilane is added into toluene to prepare a solution with the concentration of 3.75 per mill, the ITO glass substrate is immersed in the solution and stands for 2 hours, and the temperature is controlled to be 85 ℃.

The invention has the further improvement that the polymer film material in the step (2) is soluble polythiophene, and the substance films 1 and 2 are obtained under the same preparation condition without obvious difference.

The further improvement of the invention is that in the step (3), the discharge power of the oxygen plasma is 200 watts, the air pressure is 20 pascals, the etching speed is 1 nanometer/second, and the etching time is 12 seconds.

Compared with the prior art, the invention has at least the following beneficial technical effects:

(1) the invention combines the low-pressure oxygen plasma etching technology with the ultraviolet electron spectroscopy, can detect the ultraviolet photoelectron spectroscopy, namely the sub-layer ultraviolet photoelectron spectroscopy, at different depth positions of the polymer semiconductor film and obtain the energy level distribution.

(2) The invention is beneficial to exploring the relation between the properties of the polymer semiconductor film and the performances of the photoelectronic device, and has wide application prospect in the field of film analysis.

(3) The low-pressure oxygen plasma etching technology adopted by the invention has lower cost, and is economical and practical.

Drawings

FIG. 1 shows the UV-photoelectron spectrum of P3HT film with binding energy on the abscissa. Wherein (a) in FIG. 1 is a full spectrum; FIG. 1 (b) is a secondary electron cut-off diagram; FIG. 1 (c) is a Fermi-edge diagram.

FIG. 2 is a diagram showing the ultraviolet absorption spectrum of a P3HT film. The spectra have been normalized at the 0-1 vibration absorption peak.

Detailed Description

The invention is further illustrated with reference to the following figures and examples, without however being limited thereto.