Tseng Yi-Tang, Lu Li-Syuan, Shen Fang-Chun, Wang Che-Hung, Sung Hsin-Ya, Chang Wen-Hao, Wu Wen-Wei
Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, No. 1001, University Rd., East Dist., Hsinchu City, 30010, Taiwan.
Department of Electrophysics, National Yang Ming Chiao Tung University, No. 1001, University Rd., East Dist., Hsinchu City, 30010, Taiwan.
Small. 2022 Feb;18(7):e2106411. doi: 10.1002/smll.202106411. Epub 2022 Jan 7.
2D materials have great potential for not only device scaling but also various applications. To prompt the development of 2D electronics and optoelectronics, a better understanding of the limitation of materials is essential. Material failure caused by bias can lead to variations in device behavior and even electrical breakdown. In this study, the structural evolution of monolayer MoS with high bias is revealed via in situ transmission electron microscopy at the atomic scale. The biasing process is recorded and studied with the aid of aberration-corrected scanning transmission electron microscopy. The effects of electron beam irradiation and biasing are also discussed through the combination of experiments and theory. It is found that the Mo nanoclusters result from disintegration of MoS and sulfur depletion, which are induced by Joule heating. The thermal stress can also damage the MoS layer and form long cracks in both in situ and ex situ biasing cases. Investigation of the results obtained with different applied voltages helps to further verify the mechanism of evolution and provide a comprehensive study of the function of biasing.
二维材料不仅在器件缩放方面具有巨大潜力，而且在各种应用中也有很大潜力。为了推动二维电子学和光电子学的发展，深入了解材料的局限性至关重要。由偏压引起的材料失效会导致器件性能变化甚至电击穿。在本研究中，通过原位透射电子显微镜在原子尺度上揭示了高偏压下单层MoS的结构演变。借助像差校正扫描透射电子显微镜记录并研究了偏压过程。还通过实验与理论相结合的方式讨论了电子束辐照和偏压的影响。研究发现，Mo纳米团簇是由MoS分解和硫耗尽产生的，这是由焦耳热引起的。在原位和非原位偏压情况下，热应力也会破坏MoS层并形成长裂纹。对不同施加电压下获得的结果进行研究有助于进一步验证演变机制，并对偏压的作用进行全面研究。
