Metal and zinc oxide doped magnesium oxide secondary electron emission film and preparation method thereof

Abstract

The invention relates to a secondary-electron emission thin film containing metal and zinc oxide doped magnesium oxide, and a preparation method thereof. The secondary-electron emission thin film containing the metal and zinc oxide doped magnesium oxide comprises a substrate and a zinc oxide doped magnesium oxide film layer and a metal doped magnesium oxide film layer sequentially arranged on thesubstrate from top to bottom. In the metal doped magnesium oxide film layer, a metal material is singly doped or the metal material and zinc oxide are co-doped, the percentage content of the atomic number of the metal in the metal doped magnesium oxide film layer prepared from the singly doped metal material is 6 percent to 30 percent, the percentage content of the atomic number of the metal in the metal doped magnesium oxide film layer prepared from the co-doped metal material and zinc oxide is 5 percent to 25 percent, and the percentage content of the atomic number of zinc is not higher than5 percent; the size of an Mg-Zn-O composite grain formed in the zinc oxide doped magnesium oxide film layer is 8nm to 30nm, and the percentage content of the atomic number of the zinc is 0.2 percentto 8 percent. The secondary-electron emission thin film containing the metal and the zinc oxide doped magnesium oxide is prepared by adopting a sputtering method, the secondary-electron emission coefficient can be effectively improved, and the stability of electron emission is improved.

Description

technical field [0001] The invention belongs to the technical field of optoelectronic materials and devices, in particular to a metal and zinc oxide doped magnesium oxide secondary electron emission film and a preparation method thereof, which can be applied to devices such as electron multipliers and photomultiplier tubes. Background technique [0002] Magnesium oxide thin film has been widely used as a secondary electron emission material in image intensifiers, electron multipliers, photomultiplier tubes and positive electrodes because of its high secondary electron emission coefficient, good resistance to charged particle bombardment, and simple preparation process. Cross-field amplifiers and other electronic devices. In order to obtain a longer service life for electronic devices, the secondary electron emission materials used in them must be able to withstand the long-term bombardment of electron beams with a large beam current density, so the thickness of the prepared ...

AI Technical Summary

Problems solved by technology

However, experimental studies have shown that metal-doped magnesium oxide composite films still have a certain degree of secondary electron emission attenuation under the bombardment of relatively large beam currents. Decomposition etching of magnesium oxide by bombardment

Doping metal materials in the magnesium oxide film can improve the conductivity of the film, but because the secondary electron emission coefficient of the metal material is very low, and the metal particles are easy to agglomerate during the high-temperature deposition process, the surface of the film is increased. Roughness, so excessive metal doping will significantly reduce the secondary electron emission coefficient of the film, resulting in the limitation of the amount of metal doping in the magnesium oxide film

A small amount of metal doping can improve the conductivity of magnesium oxide film to a certain extent. When the metal-doped magnesium oxide film is bombarded by electron beams with lower beam current density to produce secondary electron emission, the surface charging phenomenon can be avoided, but when It is continuously bombarded by electron beams with higher beam current density, and the conductivity of the film is still insufficient when the secondary electrons are emitted, resulting in the rapid accumulation of positive charges on the surface of the film is difficult to eliminate in time

In addition, magnesium oxide will undergo decomposition and etching under the bombardment of electron beams with higher beam current density, destroying the crystal structure of magnesium oxide and changing the surface morphology of the film, resulting in attenuation of secondary electron emission.

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