Toral-Lopez Alejandro, Marin Enrique G, Pasadas Francisco, Gonzalez-Medina Jose Maria, Ruiz Francisco G, Jiménez David, Godoy Andres
Departamento de Electrónica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
Dipartimento di Ingegneria dell'Informazione, Università di Pisa, 56122 Pisa, Italy.
Nanomaterials (Basel). 2019 Jul 18;9(7):1027. doi: 10.3390/nano9071027.
Graphene-based devices are planned to augment the functionality of Si and III-V based technology in radio-frequency (RF) electronics. The expectations in designing graphene field-effect transistors (GFETs) with enhanced RF performance have attracted significant experimental efforts, mainly concentrated on achieving high mobility samples. However, little attention has been paid, so far, to the role of the access regions in these devices. Here, we analyse in detail, via numerical simulations, how the GFET transfer response is severely impacted by these regions, showing that they play a significant role in the asymmetric saturated behaviour commonly observed in GFETs. We also investigate how the modulation of the access region conductivity (i.e., by the influence of a back gate) and the presence of imperfections in the graphene layer (e.g., charge puddles) affects the transfer response. The analysis is extended to assess the application of GFETs for RF applications, by evaluating their cut-off frequency.
基于石墨烯的器件计划增强硅基和III-V族基技术在射频（RF）电子学中的功能。设计具有增强射频性能的石墨烯场效应晶体管（GFET）的期望引发了大量实验工作，主要集中在获得高迁移率样品上。然而，到目前为止，这些器件中接入区的作用很少受到关注。在这里，我们通过数值模拟详细分析了接入区如何严重影响GFET的转移响应，表明它们在GFET中常见的不对称饱和行为中起着重要作用。我们还研究了接入区电导率的调制（即通过背栅的影响）以及石墨烯层中缺陷（例如电荷 puddles）的存在如何影响转移响应。通过评估其截止频率，将分析扩展到评估GFET在射频应用中的应用。
