GNRFET输运特性中的负微分电阻效应研究

Study on Negative Differential Resistance in Transport Properties of GNRFET

利用密度泛函理论与非平衡格林函数相结合的数值分析方法,以均匀型和十字型两种不同类型的石墨烯纳米带作为沟道,研究了石墨烯纳米带场效应管(GNRFET)的负微分电阻效应。分析了不同类型GNRFET的端口输运性质:均匀型GNRFET具有良好的输运特性;十字型GNRFET由于中间的干破坏了原来两边缘的输运路径,其传输系数均不超过1。十字型GNRFET的输出特性具有明显的负微分电阻效应,且栅电压对此有调控作用。从传输谱的角度给出了GNRFET负微分电阻特性的理论解释和栅压调控的能量图,为微纳器件负微分电阻效应的研究提供了一定的理论依据。

Using the numerical analysis methods of density functional theory and non-equilibrium Green＇s function,the negative differential resistance（NDR）phenomenon of the graphene nanoribbon field effect transistor（GNRFET）was studied,using uniform type and cross type of graphene nanoribbon as channel.The transport properties of the two different types of GNRFET were analyzed.The uniform type of GNRFET had good transport properties,while the transmission coefficient of cross type GNRFET was not more than 1because the stem in the middle of the cross type destroyed the transport path of the original two edges.The transfer characteristics of the cross type of GNRFET which appeared NDR was modulated by the gate voltage.The NDR in GNRFET was explained from transmission spectrum and the energy diagram modulated by the gate voltage was listed.The above study has supplied a theoretical foundation for the future study of the micro-nano structures.