Fully coupled electron-phonon transport in two-dimensional-material-based devices using efficient FFT-based self-energy calculations

Abstract

Self-heating can significantly degrade the performance in silicon nanoscale devices. In this work, the impact of self-heating is investigated in nanosheet transistors made of two-dimensional materials using ab-initio techniques. A new algorithm was developed to allow for efficient self-energy computations, achieving a ∼500 times speedup. It is found that for the simple case of free-standing transition-metal dicalchogenides without explicit metal leads, electron-phonon scattering with room-temperature phonons dominates the device performance. For MoS₂, the effect of self-heating is negligible in comparison. For WS₂ and especially for WSe₂, self-heating effects demonstrate a further degradation of the ON-state current.