Shen Yan, Han Yuchen, Zhan Runze, Zhao Peng, Zhang Yu, Liu Fei, Chen Jun, She Juncong, Xu Ningsheng, Deng Shaozhi
State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, P. R. China.
ACS Appl Mater Interfaces. 2020 Aug 5;12(31):35354-35364. doi: 10.1021/acsami.0c09345. Epub 2020 Jul 22.
In order to develop a field emission cold cathode for power vacuum electronic device applications, it is important to realize the properties of large-current and high current density. This requires the design and preparation of cold cathode materials with good crystallization, suitable geometric structure, and good contact interface. In this study, we report a pyramidal molybdenum nanostructure with single crystalline nature, which was self-assembly grown by a thermal evaporation method. We also report the optimization of the nanostructure, successfully sharpening its top end and reducing the thickness of the intermediate layer between the structure and the substrate (from 31.4 to 3.1 nm). By this way, the pyramidal molybdenum nanostructure exhibits high conductivity of about 1.8 × 10 Ω cm. The cold cathode composed by these nanostructures shows a large-current field emission performance, with the largest emission current of 47.62 mA as well as the highest current density of 2.38 A cm, under a pulsed electric field as high as 28 V μm. The proposed pyramidal molybdenum nanostructures provide a candidate for the large-current cold cathode of the power electronic devices.
为了开发用于功率真空电子器件应用的场发射冷阴极，实现大电流和高电流密度的特性很重要。这需要设计和制备具有良好结晶性、合适几何结构和良好接触界面的冷阴极材料。在本研究中，我们报道了一种具有单晶性质的金字塔形钼纳米结构，它是通过热蒸发法自组装生长的。我们还报道了纳米结构的优化，成功地锐化了其顶端并减小了结构与衬底之间中间层的厚度（从31.4纳米减小到3.1纳米）。通过这种方式，金字塔形钼纳米结构表现出约1.8×10Ω·cm的高电导率。由这些纳米结构组成的冷阴极在高达28V/μm的脉冲电场下表现出大电流场发射性能，最大发射电流为47.62mA，最高电流密度为2.38A/cm²。所提出的金字塔形钼纳米结构为功率电子器件的大电流冷阴极提供了一种候选材料。
