Dang Minh Nhat, Nguyen Minh Dang, Hiep Nguyen Khac, Hong Phan Ngoc, Baek In Hyung, Hong Nguyen Tuan
The Australian Research Council (ARC) Industrial Transformation Training Centre in Surface Engineering for Advanced Materials (SEAM), Faculty of Science, Engineering and Technology, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122, Australia.
Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA.
Nanomaterials (Basel). 2020 Sep 27;10(10):1931. doi: 10.3390/nano10101931.
We herein present an alternative geometry of nanostructured carbon cathode capable of obtaining a low turn-on field, and both stable and high current densities. This cathode geometry consisted of a micro-hollow array on planar carbon nanostructures engineered by femtosecond laser. The micro-hollow geometry provides a larger edge area for achieving a lower turn-on field of 0.70 V/µm, a sustainable current of approximately 2 mA (about 112 mA/cm) at an applied field of less than 2 V/µm. The electric field in the vicinity of the hollow array (rim edge) is enhanced due to the edge effect, that is key to improving field emission performance. The edge effect of the micro-hollow cathode is confirmed by numerical calculation. This new type of nanostructured carbon cathode geometry can be promisingly applied for high intensity and compact electron sources.
我们在此展示了一种纳米结构碳阴极的替代几何结构，它能够获得低开启场以及稳定且高的电流密度。这种阴极几何结构由飞秒激光加工的平面碳纳米结构上的微空心阵列组成。微空心几何结构提供了更大的边缘面积，从而实现了0.70 V/µm的较低开启场，在小于2 V/µm的外加场下可持续电流约为2 mA（约112 mA/cm）。由于边缘效应，空心阵列（边缘）附近的电场增强，这是提高场发射性能的关键。微空心阴极的边缘效应通过数值计算得到证实。这种新型的纳米结构碳阴极几何结构有望应用于高强度和紧凑型电子源。
