{"title":"Surface modification approach to improve the secondary electron emission properties of Al and Au Co-doped MgO film","authors":"Yue Su, Jie Li, Shengli Wu, Wenbo Hu","doi":"10.1016/j.vacuum.2025.114497","DOIUrl":null,"url":null,"abstract":"<div><div>MgO thin films have gained significant attention because of their remarkable secondary electron emission (SEE) properties and the potential applications in the field of electron multiplication. However, the enhancement of SEE yield (SEY) is typically accompanied by a significant deterioration in the decay rate of SEY. The accelerated decay rate under prolonged electron bombardment appears to be a critical factor hindering the development of corresponding electron multipliers. In this study, we report a simple surface modification approach to improve SEE properties for Al and Au co-doped MgO thin films prepared by reactive magnetron sputtering method. This approach not only achieves high SEY but also reduces the decay rate simultaneously. Compared to the original co-doped thin films, the final composite film exhibited an increase of SEY from 5.03 to 5.34 at the incident electron energy Ep = 200eV and a decrease of decay rate from 13.3 % to 12.2 % under 2 h consistent electron bombardment. Furthermore, when implemented as the SEE layer in nine-stage discrete dynode electron multiplication system, the device with composite films featuring an Al-doped MgO surface modification exhibited a remarkable 2.5-fold gain enhancement and significantly improved stability, manifested by a reduction in gain decay rate from 14 % to 5.2 %.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114497"},"PeriodicalIF":3.8000,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Vacuum","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0042207X25004877","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
MgO thin films have gained significant attention because of their remarkable secondary electron emission (SEE) properties and the potential applications in the field of electron multiplication. However, the enhancement of SEE yield (SEY) is typically accompanied by a significant deterioration in the decay rate of SEY. The accelerated decay rate under prolonged electron bombardment appears to be a critical factor hindering the development of corresponding electron multipliers. In this study, we report a simple surface modification approach to improve SEE properties for Al and Au co-doped MgO thin films prepared by reactive magnetron sputtering method. This approach not only achieves high SEY but also reduces the decay rate simultaneously. Compared to the original co-doped thin films, the final composite film exhibited an increase of SEY from 5.03 to 5.34 at the incident electron energy Ep = 200eV and a decrease of decay rate from 13.3 % to 12.2 % under 2 h consistent electron bombardment. Furthermore, when implemented as the SEE layer in nine-stage discrete dynode electron multiplication system, the device with composite films featuring an Al-doped MgO surface modification exhibited a remarkable 2.5-fold gain enhancement and significantly improved stability, manifested by a reduction in gain decay rate from 14 % to 5.2 %.
期刊介绍:
Vacuum is an international rapid publications journal with a focus on short communication. All papers are peer-reviewed, with the review process for short communication geared towards very fast turnaround times. The journal also published full research papers, thematic issues and selected papers from leading conferences.
A report in Vacuum should represent a major advance in an area that involves a controlled environment at pressures of one atmosphere or below.
The scope of the journal includes:
1. Vacuum; original developments in vacuum pumping and instrumentation, vacuum measurement, vacuum gas dynamics, gas-surface interactions, surface treatment for UHV applications and low outgassing, vacuum melting, sintering, and vacuum metrology. Technology and solutions for large-scale facilities (e.g., particle accelerators and fusion devices). New instrumentation ( e.g., detectors and electron microscopes).
2. Plasma science; advances in PVD, CVD, plasma-assisted CVD, ion sources, deposition processes and analysis.
3. Surface science; surface engineering, surface chemistry, surface analysis, crystal growth, ion-surface interactions and etching, nanometer-scale processing, surface modification.
4. Materials science; novel functional or structural materials. Metals, ceramics, and polymers. Experiments, simulations, and modelling for understanding structure-property relationships. Thin films and coatings. Nanostructures and ion implantation.