Direct Growth of MoS2/h-BN Heterostructures via a Sulfide-Resistant Alloy
Direct Growth of MoS2/h-BN Heterostructures via a Sulfide-Resistant Alloy
复制标题
通过抗硫化合金直接生长 MoS2/h-BN 异质结构
DOI：
10.1021/acsnano.5b06254
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发表时间：
2016-02-01
期刊：
影响因子：
17.1
通讯作者：
Fu, Lei
中科院分区：
文献类型：
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作者：
Fu, Lei;Sun, Yangyong;Fu, Lei
将过渡金属二硫化物（TMDC）材料叠放在绝缘六方氮化硼（h-BN）上，可以改善其性能。因此，通过直接化学气相沉积（CVD）生长可扩展地制造TMDCs/h-BN异质结构是非常可取的。不幸的是，通过实验来实现这一点是具有挑战性的。h-BN生长的理想底物，如Ni，在合成过程中变成硫化物。这导致预生长的h-BN膜分解，因此没有TMDCs/h-BN异质结构形成。在这里，我们报告了一种完全直接的CVD方法来获得TMDCs/h-BN垂直异质结构，而无需任何中间转移步骤。这是由于使用了镍基合金，具有优异的抗硫化物性能和对h-BN生长的高催化活性。该策略能够在h-BN上直接生长出高达200 μ m(2)的MoS2单晶晶粒，这比以前的报道大了大约一个数量级。我们在h-BN上生长的单层二硫化钼的直接带隙为1.85 eV，与独立剥离的等效带隙相当接近。这种策略并不局限于基于mos2的异质结构，因此允许制造各种TMDCs/h-BN异质结构，这表明该技术在纳米电子学和光电子应用方面具有前景。
Improved properties arise in transition metal dichalcogenide (TMDC) materials when they are stacked onto insulating hexagonal boron nitride (h-BN). Therefore, the scalable fabrication of TMDCs/h-BN heterostructures by direct chemical vapor deposition (CVD) growth is highly desirable. Unfortunately, to achieve this experimentally is challenging. Ideal substrates for h-BN growth, such as Ni, become sulfides during the synthesis process. This leads to the decomposition of the pregrown h-BN film, and thus no TMDCs/h-BN heterostructure forms. Here, we report a thoroughly direct CVD approach to obtain TMDCs/h-BN vertical heterostructures without any intermediate transfer steps. This is attributed to the use of a nickel-based alloy with excellent sulfide-resistant properties and a high catalytic activity for h-BN growth. The strategy enables the direct growth of single crystal MoS2 grains of up to 200 mu m(2) on h-BN, which is approximately 1 order of magnitude larger than that in previous reports. The direct band gap of our grown single-layer MoS2 on h-BN is 1.85 eV, which is quite close to that for freestanding exfoliated equivalents. This strategy is not limited to MoS2-based heterostructures and so allows the fabrication of a variety of TMDCs/h-BN heterostructures, suggesting the technique has promise for nanoelectronics and optoelectronic applications.