Applying Molecular Dynamics to Benchmark Point Transformations for Assessing Electron Emission Mechanisms in Nonplanar Nanoscale Devices

Modeling nanodiodes requires characterizing the transitions between electron emission mechanisms [1]. "Nexus theory" matches the asymptotic solutions for source mechanisms (e.g., thermal (TE) and field (FE) emission) with the space-charge-limited current (SCLC) to determine whether one mechanism dominates or a more complete theory is required [1]. We recently applied point transformations (PT) to assess the transitions between TE, FE, and SCLC for a tip-to-plane geometry (TTPG), in agreement with particle-in-cell (PIC) results [2].

At nanoscale, molecular dynamics (MD) simulations may be used. We modify an MD code [3] to incorporate TE and FE in a TTPG. The current density determined for a TTPG and a planar geometry of the same canonical gap distance from PT using MD; exact first principles coupling kinematics and electrostatics; and the asymptotes for TE, FE, and SCLC agree well.

[1] A. M. Darr, C. R. Darr, and A. L. Garner, Phys. Rev. Res. 2, 033137 (2020).

[2] A. G. Sinelli, L. I. Breen, N. R. Sree Harsha, A. M. Darr, A. M. Komrska, and A. L. Garner, IEEE Trans. Electron Devices, 72, 397-403 (2025).

[3] K. Torfason, A. Valfells, and A. Manolescu, Phys. Plasmas 22, 033109 (2015).

This work was supported by SCALE: U.S. DoD under Contract W52P1J-22-9-3009 and AFOSR under Grant No. FA9550-22-1-0499.