Molecular transistors operating in the quantum tunneling regime represent potential electronic building blocks for future integrated circuits. However, due to their complex fabrication processes and poor stability, traditional molecular transistors can only operate stably at cryogenic temperatures. Here, through a combined experimental and theoretical investigation, we demonstrate a new design of vertical molecular tunneling transistors, with stable switching operations up to room temperature, formed from cross-plane graphene/self-assembled monolayer (SAM)/gold heterostructures. We show that vertical molecular junctions formed from pseudo-p-bis((4-(acetylthio)phenyl)ethynyl)-p-[2,2]cyclophane (PCP) SAMs exhibit destructive quantum interference (QI) effects, which are absent in 1,4-bis(((4-acetylthio)phenyl)ethynyl)benzene (OPE3) SAMs. Consequently, the zero-bias differential conductance of the former is only about 2% of the latter, resulting in an enhanced on-off current ratio for (PCP) SAMs. Field-effect control is achieved using an ionic liquid gate, whose strong vertical electric field penetrates through the graphene layer and tunes the energy levels of the SAMs. The resulting on-off current ratio achieved in PCP SAMs can reach up to ~330, about one order of magnitude higher than that of OPE3 SAMs. The demonstration of molecular junctions with combined QI effect and gate tunability represents a critical step toward functional devices in future molecular-scale electronics.

中文翻译：

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量子干扰介导的垂直分子隧道晶体管。

在量子隧道机制中运行的分子晶体管代表了未来集成电路的潜在电子构建模块。然而，由于其制造工艺复杂且稳定性差，传统分子晶体管只能在低温下稳定运行。在这里，通过结合实验和理论研究，我们展示了一种由交叉平面石墨烯/自组装单层（SAM）/金异质结构形成的垂直分子隧道晶体管的新设计，在室温下具有稳定的开关操作。我们发现，由伪-p-双((4-(乙酰硫基)苯基)乙炔基)-p- [ 2,2]环芳烷(PCP) SAM形成的垂直分子结表现出破坏性量子干涉(QI)效应，而这种效应在1,4-双(((4-乙酰硫基)苯基)乙炔基)苯(OPE3) SAM。因此，前者的零偏置微分电导仅为后者的 2% 左右，从而提高了 (PCP) SAM 的开关电流比。场效应控制是通过离子液体门实现的，其强大的垂直电场穿透石墨烯层并调节 SAM 的能级。PCP SAM 中实现的开关电流比可达约 330，比 OPE3 SAM 高出约一个数量级。具有 QI 效应和栅极可调谐性的分子结的演示代表了朝着未来分子级电子学中的功能器件迈出的关键一步。