Magnesium oxide secondary electron emission film doped with metal and aluminum oxide and preparation method thereof

Abstract

The invention discloses a magnesium oxide secondary electron emission thin film doped with metal and aluminum oxide and a preparation method thereof. The secondary electron emission thin film is composed of three layers of thin films, namely the bottom magnesium oxide film layer doped with the metal material, the middle magnesium oxide film layer doped with the aluminum oxide and the top pure magnesium oxide film layer. The preparation method comprises the following steps that a sputtering method is adopted for preparing each film layer of the secondary electron emission thin film, when the film layers are sequentially deposited, a metal substrate is kept at a certain temperature between 200-550 DEG C, argon and oxygen are introduced into a coating cavity at the same time, and the coatingcavity is kept at a certain air pressure between 0.2-1 Pa. According to the magnesium oxide secondary electron emission thin film doped with the metal and the aluminum oxide and the preparation methodthereof, the surface of the secondary electron emission thin film prepared through the method has lower roughness and a moderate magnesium oxide grain size, a proper amount of the aluminum oxide is doped in the magnesium oxide at the middle layer so that the band gap of the magnesium oxide can be reduced, the electron transport characteristic of the thin film is improved, and therefore the secondary electron emission thin film has high secondary electron emission performance.

Description

technical field [0001] The invention belongs to the technical field of optoelectronic materials and devices, and relates to a secondary electron emission film that can be used in devices such as electron multipliers and photomultiplier tubes and a preparation method thereof. Background technique [0002] Magnesium oxide thin film is widely used as secondary electron emission material in image intensifier, electron multiplier, photomultiplier tube, orthogonal In devices such as field amplifiers and plasma displays. When used in devices such as electron multipliers and photomultiplier tubes, in order to obtain a long service life for the devices, the secondary electron emission materials must be able to withstand the long-term bombardment of electron beams with a large beam current density, so the prepared magnesium oxide film The thickness needs to reach tens of nanometers or even more than one hundred nanometers. However, since magnesium oxide is an insulating material, a ...

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Problems solved by technology

[0004] However, experimental studies have shown that in the process of preparing magnesium oxide composite films doped with metal materials by sputtering, the agglomeration of metal materials during deposition will increase the surface roughness of the film, and higher surface roughness will increase the surface roughness of the film. Reduce the secondary electron emission coefficient of the film, thus restricting the further improvement of the secondary electron emission performance of the magnesium oxide composite film doped with metal materials

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