Dastgeer Ghulam, Nisar Sobia, Shahzad Zafar Muhammad, Rasheed Aamir, Kim Deok-Kee, Jaffery Syed Hassan Abbas, Wang Liang, Usman Muhammad, Eom Jonghwa
Department of Physics and Astronomy, Sejong University, Seoul, 05006, Korea.
Department of Electrical Engineering, Sejong University, Seoul, 05006, Korea.
Adv Sci (Weinh). 2022 Nov 14;10(1):e2204779. doi: 10.1002/advs.202204779.
Van der Waals (vdW) heterostructures composed of atomically thin two-dimensional (2D) materials have more potential than conventional metal-oxide semiconductors because of their tunable bandgaps, and sensitivities. The remarkable features of these amazing vdW heterostructures are leading to multi-functional logic devices, atomically thin photodetectors, and negative differential resistance (NDR) Esaki diodes. Here, an atomically thin vdW stacking composed of p-type black arsenic (b-As) and n-type tin disulfide (n-SnS ) to build a type-III (broken gap) heterojunction is introduced, leading to a negative differential resistance device. Charge transport through the NDR device is investigated under electrostatic gating to achieve a high peak-to-valley current ratio (PVCR), which improved from 2.8 to 4.6 when the temperature is lowered from 300 to 100 K. At various applied-biasing voltages, all conceivable tunneling mechanisms that regulate charge transport are elucidated. Furthermore, the real-time response of the NDR device is investigated at various streptavidin concentrations down to 1 pm, operating at a low biasing voltage. Such applications of NDR devices may lead to the development of cutting-edge electrical devices operating at low power that may be employed as biosensors to detect a variety of target DNA (e.g., ct-DNA) and protein (e.g., the spike protein associated with COVID-19).
由原子级薄的二维（2D）材料组成的范德华（vdW）异质结构，由于其可调节的带隙和灵敏度，比传统的金属氧化物半导体具有更大的潜力。这些令人惊叹的vdW异质结构的显著特性正促使多功能逻辑器件、原子级薄的光电探测器和负微分电阻（NDR）埃萨基二极管的出现。在此，介绍了一种由p型黑砷（b-As）和n型二硫化锡（n-SnS₂）组成的原子级薄的vdW堆叠结构，用于构建III型（断裂带隙）异质结，从而得到一种负微分电阻器件。在静电门控下研究了通过NDR器件的电荷传输，以实现高的峰谷电流比（PVCR），当温度从300 K降至100 K时，该比值从2.8提高到了4.6。在各种施加的偏置电压下，阐明了所有可想象的调节电荷传输的隧穿机制。此外，还研究了NDR器件在低至1皮米的各种链霉亲和素浓度下，在低偏置电压下工作时的实时响应。NDR器件的此类应用可能会推动低功耗前沿电子器件的发展，这些器件可用作生物传感器来检测各种目标DNA（例如，ct-DNA）和蛋白质（例如，与COVID-19相关的刺突蛋白）。
