Abstract Graphene-based van der Waals heterostructure (vdWH) comprising of HfN2 monolayer stacked over graphene has been designed and studied based on density functional theory. The vdWH forms a n-type Schottky contact with a Schottky barrier height (SBH) of 0.67 eV, while it exhibits p-type SBH of 0.93 eV. The response of SBH and electrical contact properties to external perturbation, such as, vertical strain and electric field has been investigated thoroughly. Under the application of strain and normal electric field within range of ±0.3 V/A, the type of electrical contacts, i.e., n/p type Schottky or Ohmic, is found to be interconvertible, while electron/hole doping in graphene is tunable by a doping carrier concentration of up to ~1013 cm−2, which lies between experimentally observed molecular doping (~1012 cm−2) and electrolytic gating (~1014 cm−2). Such an extremely high tunability in electrical contacts, doping carrier concentration along with its excellent optical response in the visible light region shows unrivalled potential of this vdWH in high performance graphene-based futuristic Schottky transistors with high on/off ratio, ultrathin phototransistor with high gain, low-power multivalued optical non volatile memory devices, and nanoelectronics.

中文翻译：

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基于二维 HfN2/石墨烯界面的肖特基器件：通过静电门控和面外应变实现电接触和载流子浓度无与伦比的可控性

摘要 基于密度泛函理论设计和研究了基于石墨烯的范德华异质结构 (vdWH)，包括堆叠在石墨烯上的 HfN2 单层。vdWH 形成 n 型肖特基接触，肖特基势垒高度 (SBH) 为 0.67 eV，而 p 型 SBH 为 0.93 eV。SBH 和电接触特性对外部扰动（例如垂直应变和电场）的响应已得到彻底研究。在 ±0.3 V/A 范围内的应变和法向电场的应用下，发现电接触的类型，即 n/p 型肖特基或欧姆型是可相互转换的，而石墨烯中的电子/空穴掺杂可通过以下方式进行调节高达 ~1013 cm-2 的掺杂载流子浓度，它介于实验观察到的分子掺杂 (~1012 cm-2) 和电解门控 (~1014 cm-2) 之间。这种电接触的极高可调性、掺杂载流子浓度及其在可见光区域的出色光学响应显示了这种 vdWH 在高性能基于石墨烯的未来肖特基晶体管中的无与伦比的潜力，具有高开/关比、具有高增益的超薄光电晶体管、低功耗多值光学非易失性存储器件和纳米电子学。