论文标题
对超高峰值与valley电流比的半导体负差分电阻隧道二极管的提议
Proposal for semiconductor-free negative differential resistance tunnel diode with ultra-high peak-to-valley current ratio
论文作者
论文摘要
负差分电阻（NDR）隧道二极管是超越流体计算的有前途的替代设备，因为它们与晶体管集成时提供了多种潜在的应用。我们提出了一种新型的无半导体NDR隧道二极管概念，该二极管概念具有超高的峰值与谷水电流比（PVCR）值。我们提出的NDR二极管由两个冷隧道屏障隔开的冷金属电极组成。 NDR效应源于冷金属电极的独特电子带结构，即，围绕费米水平的隔离金属带的宽度以及分隔较高和下层带的能量差距，确定了电流 - 较高和下层带的宽度（$ i $ - $ - $ $ v $）和隧道二极管的PVCR值。通过正确选择冷金属电极材料，可以获得常规的N型或$λ$ -Type NDR效果。二维（2D）材料为实现拟议的NDR隧道二极管的实现提供了独特的平台。 To demonstrate the proof of concept we employ the nonequilibrium Green function method combined with density functional theory to calculate the $I$-$V$ characteristic of the lateral (AlI$_2$/MgI$_2$/AlI$_2$) and vertical (NbS$_2$/h-BN/NbS$_2$) heterojunction tunnel diodes based on 2D cold metals.对于横向隧道二极管，我们在室温下获得了$λ$ -Type NDR效果，其超高PVCR值为10 $^{16} $，而垂直隧道二极管具有常规的N型NDR效果，较小的PVCR值约为10 $^4 $。拟议的概念为NDR设备提供了无半导体的解决方案，以实现带有超高PVCR值的所需$ i $ - $ V $特性用于内存和逻辑应用程序。
The negative differential resistance (NDR) tunnel diodes are promising alternative devices for beyond-CMOS computing as they offer several potential applications when integrated with transistors. We propose a novel semiconductor-free NDR tunnel diode concept that exhibits an ultra-high peak-to-valley current ratio (PVCR) value. Our proposed NDR diode consists of two cold metal electrodes separated by a thin insulating tunnel barrier. The NDR effect stems from the unique electronic band structure of the cold metal electrodes, i.e., the width of the isolated metallic bands around the Fermi level as well as the energy gaps separating higher- and lower-lying bands determine the current-voltage ($I$-$V$) characteristics and the PVCR value of the tunnel diode. By proper choice of the cold metal electrode materials, either a conventional N-type or $Λ$-type NDR effect can be obtained. Two-dimensional (2D) materials offer a unique platform for the realization of proposed NDR tunnel diodes. To demonstrate the proof of concept we employ the nonequilibrium Green function method combined with density functional theory to calculate the $I$-$V$ characteristic of the lateral (AlI$_2$/MgI$_2$/AlI$_2$) and vertical (NbS$_2$/h-BN/NbS$_2$) heterojunction tunnel diodes based on 2D cold metals. For the lateral tunnel diode, we obtain a $Λ$-type NDR effect with an ultra-high PVCR value of 10$^{16}$ at room temperature, while the vertical tunnel diode exhibits a conventional N-type NDR effect with a smaller PVCR value of about 10$^4$. The proposed concept provides a semiconductor-free solution for NDR devices to achieve desired $I$-$V$ characteristics with ultra-high PVCR values for memory and logic applications.
