模拟多尺度门控场致发射体--一种混合方法
Simulating multiscale gated field emitters -- a hybrid approach
摘要：
多级阴极是场致发射的有希望的候选者，这是由于肖特基猜想及其最近校正的对应物预测的局部场中的倍增效应[J. Vac. Sci. B 38，023208（2020）]。由于即使在由宏观基底和微观突起组成的2级复合结构中，长度尺度的变化也很大，因此需要重新审视门控场发射复合二极管的模拟方法。作为该策略的一部分，作者调查了复合发射体的表面上的局部场在其顶点附近的变化，并发现广义余弦定律在多尺度门控阴极的尖端附近继续保持局部。这是用来发射电荷的位置和速度分量的知识，只有在顶点处的电场的适当分布。该分布与当代自由电子场致发射模型一致，并遵循发射角、总能量和法向能量的联合分布。对于局部场增强因子约为1000的复合几何形状，使用混合模型，其中使用COMSOL计算的真空场导入到粒子单元代码PASUPAT中，其中实施发射模块。空间电荷效应被纳入一个多尺度适应的PASUPAT使用截断的几何形状与“开放的静电边界”条件。空间电荷场与真空场相结合，用于粒子发射和跟踪。
英文摘要：
Multi-stage cathodes are promising candidates for field emission due to the multiplicative effect in local field predicted by the Schottky conjecture and its recent corrected counterpart [J. Vac. Sci. Technol. B 38, 023208 (2020)]. Due to the large variation in length scales even in a 2-stage compound structure consisting of a macroscopic base and a microscopic protrusion, the simulation methodology of a gated field emitting compound diode needs to be revisited. As part of this strategy, the authors investigate the variation of local field on the surface of a compound emitter near its apex and find that the generalized cosine law continues to hold locally near the tip of a multi-scale gated cathode. This is used to emit charges with appropriate distributions in position and velocity components with a knowledge of only the electric field at the apex. The distributions are consistent with contemporary free-electron field emission model and follow from the joint distribution of launch angle, total energy, and normal energy. For a compound geometry with local field enhancement by a factor of around 1000, a hybrid model is used where the vacuum field calculated using COMSOL is imported into the Particle-In-Cell code PASUPAT where the emission module is implemented. Space charge effects are incorporated in a multi-scale adaptation of PASUPAT using a truncated geometry with `open electrostatic boundary' condition. The space charge field, combined with the vacuum field, is used for particle-emission and tracking.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
