Gate-versus defect-induced voltage drop and negative differential resistance in vertical graphene heterostructures

作     者：Tae Hyung Kim Juho Lee Ryong-Gyu Lee Yong-Hoon Kim 

作者机构：School of Electrical EngineeringKorea Advanced Institute of Science and Technology(KAIST)291 Daehak-roYuseong-guDaejeon34141Korea 

出 版 物：《npj Computational Materials》 (计算材料学（英文）)

年 卷 期：2022年第8卷第1期

页      面：480-488页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：This work was supported by the Samsung Research Funding&Incubation Center of Samsung Electronics(No.SRFC-TA2003-01) Computational resources were provided by KISTI Supercomputing Center(KSC-2018-C2-0032) 

主　　题：defect resistance details 

摘      要：To enable the computer-aided design of vertically stacked two-dimensional(2D)van der Waals(vdW)heterostructure devices,we here introduce a non-equilibrium first-principles simulation method based on the multi-space constrained-search density functional *** it to graphene/few-layer hBN/graphene field-effect transistors,we show that the negative differential resistance(NDR)characteristics can be produced not only from the gating-induced mismatch between two graphene Dirac cones in energy-momentum space but from the bias-dependent energetic shift of defect ***,for a carbon atom substituted for a nitrogen atom(C_(N))within inner hBN layers,the increase of bias voltage is found to induce a self-consistent electron filling of in-gap C_(N)states,which in turn changes voltage drop profiles and produces symmetric NDR *** the CN placed on outer hBN layers,however,the pinning of C_(N)states to nearby graphene significantly modifies device characteristics,demonstrating the critical impact of atomic details for 2D vdW devices.