TWI464789B - Method for adjusting work function of metal oxide film - Google Patents

Description

Method for adjusting the work function of metal oxide film

The present invention relates to a metal oxide film, and more particularly to a method of adjusting the work function of a metal oxide film.

In general, photovoltaic elements often use metal oxides as electrodes, mainly because these metal oxides have good electrical conductivity and transparency, such as indium tin oxide, zinc oxide, and the like. Therefore, metal oxide films are widely used in various types of photovoltaic elements, such as various solar cells, flat panel displays, light-emitting diodes, organic light-emitting diodes, and the like. In the case of an organic light-emitting diode, the surface work function of the anode metal oxide film must be close to that of the adjacent hole injection layer, so that the energy barrier of the interface can be reduced, and the hole can be easily transported by the anode into the hole. Floor. At present, the industry mainly uses oxygen plasma processing technology to increase the surface work function of metal oxide film, but the equipment required for this method is expensive and complicated (such as vacuum system), and the size of the sample is also limited by the size of the device. Production costs increase.

The main object of the present invention is to provide a method for adjusting the work function of a metal oxide film, comprising providing a metal oxide film having a surface and having a first work function and a plurality of a carbon contaminant; providing a closed cavity, and placing the metal oxide film in the closed cavity; injecting an activator into the sealed cavity; introducing a carbon dioxide gas into the sealed cavity; and raising the The pressure and temperature in the closed chamber are such that the carbon dioxide gas enters a supercritical state to form a supercritical fluid having a pressure in the closed chamber of 2000 to 10,000 psi and a temperature in the closed chamber of 30 to 300 And the supercritical flow system removes the carbon contaminants on the surface of the oxide film and has a second work function on the surface of the metal oxide film. Since the carbon contaminants on the surface of the metal oxide film can be removed by a carbon dioxide supercritical method, the work function of the surface of the metal oxide film is significantly improved, and the carbon dioxide supercritical method is non-toxic, colorless, It is odorless and does not produce photochemical reactions. It is environmentally friendly and green. It is environmentally friendly, does not destroy the ozone layer and is recyclable.

Referring to FIG. 1 and FIGS. 2A to 2F, which are a preferred embodiment of the present invention, a method for adjusting the work function of a metal oxide film includes the following steps: First, refer to step 10 of FIG. 1 and 2A, a metal oxide film 110 is provided, the metal oxide film 110 having a surface 111 having a first work function and a plurality of carbon contaminants 111a. In the present embodiment, the metal oxide is oxidized. The film 110 is disposed on a substrate S, and the metal oxide film 110 is selected from the group consisting of indium tin oxide (ITO), antimony tin oxide (ATO), aluminum zinc oxide (AZO), tin oxide SnO, and oxidation. One of zinc (ZnO); next, please refer to steps 11 and 2B of FIG. 1 to provide a closed cavity A, and the metal oxide film 110 is placed in the sealed cavity A; In steps 12 and 2C of Fig. 1, an activator B is injected into the closed chamber A. The activator B can be selected from organic solvents such as ethanol, isopropanol, acetone, methyl ethyl ketone, hydrogen peroxide or acidity. One of the water-soluble ones, in the present embodiment, the activator B is hydrogen peroxide; Referring to steps 13 and 2D of Fig. 1, a carbon dioxide gas C is introduced into the sealed chamber A; after that, please refer to steps 14 and 2E of Fig. 1 to raise the pressure and temperature in the closed chamber A. The carbon dioxide gas C is brought into a supercritical state to form a supercritical fluid F. The pressure in the closed chamber A is between 2000 and 10,000 psi, and the temperature in the closed chamber A is between 30 and 300 degrees. And the time for raising the temperature in the sealed cavity A is not less than 15 minutes. Preferably, in the embodiment, the pressure in the closed cavity A is 4000 psi, and the sealed cavity A is The temperature is 85 degrees, and the time for raising the temperature in the sealed chamber A is 15 minutes. The supercritical fluid F can remove the carbon contaminants 111a of the surface 111 of the oxide film and The surface 111 of the metal oxide film 110 has a second work function and the second work function is greater than the first work function; finally, please refer to steps 15 and 2F of FIG. 1 to lower the closed cavity A. The pressure and temperature therein are such that the supercritical fluid F is vaporized to be separated from the metal oxide film 110, and the super-impact The fluid F may simultaneously take away these contaminants carbon gasification 111a.






Next, please refer to Table 1, Table 2 and Annex 1. As can be seen from Table 1, Table 2 and Annex 1, the carbon contaminants 111a of the surface 111 of the metal oxide film 110 can be supercritical by carbon dioxide. Therefore, the work function of the surface 111 of the metal oxide film 110 is significantly improved, and the carbon dioxide supercritical method has the characteristics of being non-toxic, colorless, odorless, and non-photochemically reactive, and is environmentally friendly and does not destroy the ozone layer. The utility model can be recycled and reused, so it is a very environmentally friendly green process. Furthermore, the present invention utilizes a carbon dioxide supercritical method to remove the carbon pollutants 111a and the removal efficiency of the carbon pollutants 111a and the oxygen plasma treatment technology. The removal efficiency is comparable, but the cost is relatively cheap compared to the oxygen plasma treatment technology, so the present invention has the effect of saving production costs.
In addition, referring to FIG. 3, when the metal oxide film 110 is applied to an Organic Light-Emitting Diode (OLED) (not shown), it is an anode material, and the The organic light-emitting diode element is displayed using the metal oxide film 110 as an anode material (as shown in FIG. 3), and the metal oxide film 110 is subjected to a carbon dioxide supercritical method and then tested for carbon dioxide. The current density and brightness of the organic light-emitting diode element of the metal oxide film 110 processed by the supercritical method are not inferior to the organic light-emitting diode element using the oxygen plasma-treated metal oxide film, and the carbon dioxide is super The current density and brightness of the organic light-emitting diode element of the metal oxide film 110 processed by the critical method far exceed the current density and brightness of the organic light-emitting diode element of the untreated metal oxide film, so that the carbon dioxide supercritical is known The method can be applied to the manufacture of large-area photovoltaic components without complicated equipment and vacuum system, and can effectively improve the element. Characteristics, and reduce the surface impedance of the element and effectively reduce the operating voltage of the element, to achieve energy saving, increased efficiency and other effects.
The scope of the present invention is defined by the scope of the appended claims, and any changes and modifications made by those skilled in the art without departing from the spirit and scope of the invention are within the scope of the present invention. .

10. . . Providing a metal oxide film having a surface and having a first work function and a plurality of carbon contaminants

11. . . Providing a sealed cavity and placing the metal oxide film in the closed cavity

12. . . Injecting an activator into the closed cavity

13. . . Passing a carbon dioxide gas into the closed cavity

14. . . Increasing the pressure and temperature in the closed chamber to cause the carbon dioxide gas to enter a supercritical state to form a supercritical fluid having a pressure in the closed chamber of 2000 to 10,000 psi and a temperature in the closed chamber of 30 Up to 300 degrees, the supercritical flow system can remove the carbon contaminants on the surface of the oxide film and have a second work function on the surface of the metal oxide film

15‧‧‧Reducing the pressure and temperature in the closed chamber to vaporize the supercritical fluid to separate from the metal oxide film, and the supercritical fluid can simultaneously take away the carbon pollutants during gasification

110‧‧‧Metal oxide film

111‧‧‧ surface

111a‧‧‧Carbon pollutants

A‧‧‧Closed cavity

B‧‧‧activator

C‧‧‧Carbon dioxide gas

F‧‧‧Supercritical fluid

S‧‧‧Substrate

Figure 1 is a flow chart showing a method of adjusting the work function of a metal oxide film in accordance with a preferred embodiment of the present invention.
2A to 2F are schematic cross-sectional views showing a method of adjusting a work function of a metal oxide film according to a preferred embodiment of the present invention.
Figure 3: According to a preferred embodiment of the present invention, an untreated metal oxide film, a metal oxide film treated by a carbon dioxide supercritical fluid, and a metal oxide film treated via an oxygen plasma are disposed on the organic light emitting diode Schematic diagram of current density and brightness measured by the body.
Annex 1 : Contact angle of untreated metal oxide film, contact angle of metal oxide film treated by carbon dioxide supercritical fluid, and contact angle of metal oxide film treated by oxygen plasma according to a preferred embodiment of the present invention Photo illustration.

10. . . Providing a metal oxide film having a surface and having a first work function and a plurality of carbon contaminants

11. . . Providing a sealed cavity and placing the metal oxide film in the closed cavity

12. . . Injecting an activator into the closed cavity

13. . . Passing a carbon dioxide gas into the closed cavity

14. . . Increasing the pressure and temperature in the closed chamber to cause the carbon dioxide gas to enter a supercritical state to form a supercritical fluid having a pressure between 2000 and 10,000 psi, and the temperature in the closed chamber is between 30 to 300 degrees, the supercritical flow system can remove the carbon contaminants on the surface of the oxide film and have a second work function on the surface of the metal oxide film

15. . . Decreasing the pressure and temperature in the closed chamber to vaporize the supercritical fluid to separate from the metal oxide film, and simultaneously extracting the carbon pollutants when the supercritical fluid is vaporized

Claims (5)

A method for adjusting a work function of a metal oxide film, comprising: providing a metal oxide film having a surface and having a first work function and a plurality of carbon contaminants; Sealing the cavity, and placing the metal oxide film in the sealed cavity; injecting an activator into the sealed cavity; introducing a carbon dioxide gas into the sealed cavity; and raising the pressure in the sealed cavity and The temperature is such that the carbon dioxide gas enters a supercritical state to form a supercritical fluid having a pressure in the closed chamber of 2000 to 10,000 psi and a temperature in the closed chamber of 30 to 300 degrees. The supercritical flow system The carbon contaminants of the surface of the oxide film may be removed and the surface of the metal oxide film has a second work function, the second work function being greater than the first work function. The method for adjusting a work function of a metal oxide film according to claim 1, further comprising a step of reducing a pressure and a temperature in the sealed chamber to vaporize the supercritical fluid to separate from the metal oxide film. The step of, and the supercritical fluid can simultaneously take away the carbon contaminants when vaporizing. The method for adjusting a work function of a metal oxide film according to claim 1, wherein the metal oxide film is selected from the group consisting of indium tin oxide (ITO), antimony tin oxide (ATO), and aluminum zinc oxide ( One of AZO), tin oxide SnO, and zinc oxide (ZnO). The method for adjusting the work function of a metal oxide film according to claim 1, wherein the activator is selected from the group consisting of organic solvents such as ethanol, isopropanol, acetone, methyl ethyl ketone, hydrogen peroxide or acid alkaline water. one. The method for adjusting the work function of a metal oxide film according to claim 1, wherein the time for raising the temperature in the sealed chamber is not less than 15 minutes.