Department of Electrical Communication Engineering, Indian Institute of Science , Bangalore 560012, India.
ACS Appl Mater Interfaces. 2018 Feb 14;10(6):5657-5664. doi: 10.1021/acsami.7b18242. Epub 2018 Feb 2.
Backward diodes conduct more efficiently in the reverse bias than in the forward bias, providing superior high-frequency response, temperature stability, radiation hardness, and 1/f noise performance than a conventional diode conducting in the forward direction. Here, we demonstrate a van der Waals material-based backward diode by exploiting the giant staggered band offsets of WSe/SnSe vertical heterojunction. The diode exhibits an ultrahigh-reverse rectification ratio (R) of ∼2.1 × 10, and the same is maintained up to an unusually large bias of 1.5 V-outperforming existing backward diode reports using conventional bulk semiconductors as well as one- and two-dimensional materials by more than an order of magnitude while maintaining an impressive curvature coefficient (γ) of ∼37 V. The transport mechanism in the diode is shown to be efficiently tunable by external gate and drain bias, as well as by the thickness of the WSe layer and the type of metal contacts used. These results pave the way for practical electronic circuit applications using two-dimensional materials and their heterojunctions.
反向二极管在反向偏置下的导通效率高于正向偏置，提供了优于传统正向导通二极管的高频响应、温度稳定性、辐射硬度和 1/f 噪声性能。在这里，我们通过利用 WSe/SnSe 垂直异质结的巨大交错能带偏移，展示了一种基于范德华材料的反向二极管。该二极管表现出超高的反向整流比（R）约为 2.1×10，并且在高达 1.5 V 的异常大偏置下保持不变，超过了使用传统体半导体以及一维和二维材料的现有反向二极管报告，同时保持令人印象深刻的曲率系数（γ）约为 37 V。结果表明，二极管中的传输机制可以通过外部栅极和漏极偏置以及 WSe 层的厚度和使用的金属接触类型来有效地进行调节。这些结果为使用二维材料及其异质结进行实际电子电路应用铺平了道路。
