Back-gated field-effect transistor (BGFET) structures are the most prominently used device platform to study the electrical properties of two-dimensional materials. These devices are widely modeled as Schottky barrier (SB)-MOSFETs assuming that the current flow is limited by the source-contact in the OFF state, while the channel limits the current in the ON state. Here, using an analytical model and drift-diffusion simulations, we show that the channel limits the overall current in the OFF state and vice versa, in contrast to past studies. Furthermore, we demonstrate how this renewed understanding helps to clarify the general underestimation of extracted SB height in experimental long-channel BGFETs.

背栅场效应晶体管 (BGFET) 结构是研究二维材料电性能最常用的器件平台。这些器件被广泛建模为肖特基势垒 (SB)-MOSFET，假设电流受关断状态下的源极接触限制，而通道限制导通状态下的电流。在这里，使用分析模型和漂移扩散模拟，我们表明与过去的研究相比，通道限制了关闭状态下的总电流，反之亦然。此外，我们展示了这种新的理解如何有助于澄清实验性长沟道 BGFET 中提取的 SB 高度的普遍低估。