LATMOS-CNRS/IPSL, University of Versailles Saint Quentin, Guyancourt, France.
Nanotechnology. 2013 Nov 22;24(46):465303. doi: 10.1088/0957-4484/24/46/465303. Epub 2013 Oct 24.
We have designed and fabricated a new type of field electron source for a novel onboard mass spectrometer. The new electron source, which is a field effect emitter in a triode configuration, consists of a CNT-column array cathode and an extraction gate with holes that are aligned concentrically with respect to the cylindrical CNT columns. In triode mode operation, cathode currents as large as ~420 μA have been emitted with an anode-to-gate current ratio of ~1.5. To account for the observed emission characteristics of the new electron source, we have carried out multi-scale simulations that combine a three-dimensional (3D) microscopic model in the vicinity of an actual emission site with a two-dimensional (2D) macroscopic model that covers the whole device structure. Because the mesh size in the microscopic 3D model is as small as 100 nm, the contributions of the extruding CNT bundle at the top edge of an electron column can be examined in detail. Unlike the macroscopic 2D simulation that shows only small field enhancement at CNT column's top edge, the multi-scale simulation successfully reproduced the local electric field strongly enough to emit the measured cathode currents and the electric field distribution which is consistent with the measured anode-to-gate current ratio.
我们设计并制造了一种新型场致发射电子源，用于新型机载质谱仪。这种新型电子源是一种三极配置的场效应发射器，由 CNT 柱阵列阴极和具有与圆柱 CNT 柱同心对准的孔的引出栅极组成。在三极模式操作下，阴极电流高达约 420 μA，阳极到栅极的电流比约为 1.5。为了解释新电子源的观察到的发射特性，我们进行了多尺度模拟，将实际发射点附近的三维（3D）微观模型与覆盖整个器件结构的二维（2D）宏观模型相结合。由于微观 3D 模型中的网格尺寸小至 100nm，可以详细检查电子柱顶部突出的 CNT 束的贡献。与仅显示 CNT 柱顶部小的场增强的宏观 2D 模拟不同，多尺度模拟成功地再现了足以发射测量到的阴极电流的局部电场，并且电场分布与测量到的阳极到栅极电流比一致。
