超低开启电场SiC场发射阴极材料

SiC, as one of the third generation wide bandgap semiconductor families with a series of superior physical performances, is considered as the excellent candidate for the field emission cathodes. However, its practical applications still rely on the further enhanced field emission properties such as obtaining a lower turn on field. In the present work, directed by the exploration of novel SiC field emission cathode materials with high performace, we will firstly realize the controlled growth and doping of the SiC nanoneedle arrays via pyrolysis of polymeric precursors, by precisely tailoring the experimental parameters. Subsequently, the resultant SiC nanoarrays will be surface decorated by the noncompact metal nanoparticles with uniform distributions via the technique of electron-bean vapor deposition with the optimized experimental parameters. The as-fabricated SiC nanoneedle arrays with the metal nanoparticle decorations might take advantage of local field enhancement effect, increasing the electron emission cites and tailoring the energy band together, which lead to the collaborative enhancement of the electron emission ability, and thus result in the significant improvement of their field emission properties. This project will be carried out systematically to characterize the electron emission performance of SiC nanoneeld arrays, clarify and optimize the relationship between their structures and the field emission properties, and disclose the mechanism of the electron emission. Current work might put forward the exploration of SiC field emission cathodes with ultra low turn on fields, and could provide some scientific data and basic theories for their potential applications.

第三代宽带系半导体SiC具有系列优良的物理特性，是优异的场发射阴极材料，在显示和真空电子等领域具有广泛的应用前景。然而，其真正应用还有赖于场发射性能的进一步提高，如获得更低的开启电场等。本项目拟以新颖高效的SiC场发射阴极材料研发为导向，首先通过有机前驱体热解工艺的精细控制，实现掺杂SiC纳米针尖阵列的生长；然后采用电子束蒸镀，通过工艺的优化，实现SiC阵列结构的金属纳米颗粒均匀非致密表面修饰，以期集局域场增强效应、增加电子发射点和能带调控等多种手段为一体，协同强化其电子发射能力，大幅度降低其开启电场。相关工作将系统检测和分析SiC场发射阴极材料的电子发射特性，阐明和优化SiC纳米阵列结构与场发射性能之间的内在关联，揭示其电子发射机理，有望获得超低开启电场的SiC柔性场发射阴极材料，为其潜在应用提供一定的科学数据和理论依据。

第三代宽带系半导体SiC具有系列优良的物理特性，是优异的场发射阴极材料，在显示和真空电子等领域具有广泛的应用前景。然而，其真正应用还有赖于场发射性能的进一步提高，如获得更低的开启电场等。本项目以新颖高效的SiC场发射阴极材料研发为目标，系统研究了有机前驱体热解工艺生长SiC纳米阵列，并通过电子束蒸镀，实现SiC阵列结构的Au金属纳米颗粒均匀非致密表面修饰，然后深入探究了其电子发射特性，通过构效关系的优化，实现了具有国际上开启电场最低的SiC场发射阴极材料的研发(低于0.5V/um)。在理论研究上，探讨了局域场增强效应、增加电子发射点和能带调控等原理，对协同强化SiC纳米阵列场发射阴极电子发射能力的影响和机理，实现了其电子发射能力的大幅度强化。.研究工作圆满完成了项目拟定的指标。发表了SCI收录论文23篇(原定指标：20篇)，SCI一区Top期刊19篇，IF均大于3(原定指标：IF大于3的12篇)，IF大于10的9篇(原定指标：力争发表IF大于10的2篇)，同时应邀为SCI一区Top期刊Prog. Mater. Sci. (2019, 104: 138-214 (IF: 23.725)) 和J. Mater. Chem. C (2017, 5: 10682-10700. (IF: 6.641))撰写综述论文2篇；获授权发明专利5项(原定指标：申请发明专利4项)。.本项目所实现的对SiC低维材料结构的精细调控原理和技术，对其他半导体低维材料的可控生长具备一定的借鉴意义，所研发的SiC低维材料的电子发射特性处国际领先水平，在各类真空电子和平板显示领域，具有一定的潜在应用前景。