An efficient model algorithm for two-dimensional field-effect transistors

TL;DR

This paper introduces an improved, numerically efficient model for 2D material-based FETs that simplifies calculations and accelerates simulations while maintaining high accuracy, facilitating integration into circuit design tools.

Contribution

The authors develop an integral-free, explicit formula for the drain-source current and a fast electrostatic potential evaluation algorithm, enhancing the QFLPS model's computational efficiency for 2DM-FETs.

Findings

Achieves two orders of magnitude faster computation than benchmark algorithms.

Maintains high accuracy with 7 to 9 significant digits.

Successfully calibrated with real device data from BP and ML-MoS2 FETs.

Abstract

Two-dimensional materials-based field-effect transistors (2DM-FETs) exhibit both ambipolar and unipolar transport types. To physically and compactly cover both cases, we put forward a quasi-Fermi-level phase space (QFLPS) approach to model the ambipolar effect in our previous work. This work aims to further improve the QFLPS model's numerical aspect so that the model can be implanted into the standard circuit simulator. We first rigorously derive the integral-free formula for the drain-source current to achieve this goal. It is more friendly to computation than the integral form. Besides, it explicitly gives the correlation terms between the electron and hole components. Secondly, to work out the boundary values required by the new expressions, we develop a fast evaluation algorithm for the surface electrostatic potential based on the zero-temperature limit property of the 2DM-FET system. By calibrating the model with the realistic device data of black phosphorus (BP) and monolayer molybdenum disulfide (ML-MoS2) FETs, the completed algorithm is tested against practical cases. The results show a typical superiority to the benchmark algorithm by two orders of magnitude in time consumption can be achieved while keeping a high accuracy with 7 to 9 significant digits.