Laser-induced electrochemical thinning of MoS2
Laser-induced electrochemical thinning of MoS2
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DOI：
10.1039/c5tc04409j
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发表时间：
2016-01-01
影响因子：
6.4
通讯作者：
Hayamizu, Yuhei
中科院分区：
文献类型：
--
作者：
Sunamura, Kaito;Page, Tamon R.;Hayamizu, Yuhei
以二硫化钼（MoS2）为代表的单层二维金属硫族化合物由于其原子级薄的结构和独特的电学和光学性质而引起了广泛的兴趣。MoS2的电性能取决于层数。单层是直接带隙半导体，在光激发下表现出强烈的光致发光，而多层是间接半导体。层数的控制对于二硫化钼作为二维半导体纳米材料的应用至关重要。在这项工作中，我们提出了一种新的方法来控制二硫化钼层的数量，其中通过激光激发可以诱导多层二硫化钼的电化学蚀刻。激光诱导刻蚀下的减薄过程是一个自限性反应。随着层数减少，电化学蚀刻变得不活跃，在衬底上留下单层或几层MoS2。蚀刻层的特征在于通过拉曼光谱和原子力显微镜。还制造了场效应晶体管（FET）以测试蚀刻的MoS2的电性质，证明了在与多层MoS2 FET相同的阈值电压下的晶体管行为。
Single layers of two-dimensional metal chalcogenides, represented by molybdenum disulfide (MoS2), have attracted wide interest due to their atomically thin structures and unique electric and optical properties. The electrical properties of MoS2 depend on the number of layers. A single layer is a direct band-gap semiconductor exhibiting strong photoluminescence under photoexcitation, while multiple layers are indirect semiconductors. The control of the number of layers is essential for the application of MoS2 as a two-dimensional semiconducting nanomaterial. In this work, we present a new approach to control the number of MoS2 layers, where excitation by a laser can induce electrochemical etching of multiple layers of MoS2. The thinning process under laser-induced etching is a self-limited reaction. Electrochemical etching becomes inactive as the number of layers is reduced, leaving a single layer or a few layers of MoS2 on the substrate. The etched layers were characterized by Raman spectroscopy and atomic force microscopy. A field effect transistor (FET) was also fabricated to test the electrical properties of the etched MoS2, demonstrating transistor behavior at the same threshold voltage as a multilayer MoS2 FET.