Li Xiao, Li Xinming, Zang Xiaobei, Zhu Miao, He Yijia, Wang Kunlin, Xie Dan, Zhu Hongwei
School of Materials Science and Engineering, State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084, China.
Nanoscale. 2015 May 14;7(18):8398-404. doi: 10.1039/c5nr00904a.
Hydrogen plays a crucial role in the chemical vapor deposition (CVD) growth of graphene. Here, we have revealed the roles of hydrogen in the two-step CVD growth of MoS2. Our study demonstrates that hydrogen acts as the following: (i) an inhibitor of the thermal-induced etching effect in the continuous film growth process; and (ii) a promoter of the desulfurization reaction by decreasing the S/Mo atomic ratio and the oxidation reaction of the obtained MoSx (0 < x < 2) films. A high hydrogen content of more than 100% in argon forms nano-sized circle-like defects and damages the continuity and uniformity of the film. Continuous MoS2 films with a high crystallinity and a nearly perfect S/Mo atomic ratio were finally obtained after sulfurization annealing with a hydrogen content in the range of 20%-80%. This insightful understanding reveals the crucial roles of hydrogen in the CVD growth of MoS2 and paves the way for the controllable synthesis of two-dimensional materials.
氢在石墨烯的化学气相沉积（CVD）生长过程中起着至关重要的作用。在此，我们揭示了氢在二硫化钼（MoS₂）两步CVD生长过程中的作用。我们的研究表明，氢起到以下作用：（i）在连续薄膜生长过程中作为热诱导蚀刻效应的抑制剂；（ii）通过降低硫/钼原子比以及所得MoSₓ（0 < x < 2）薄膜的氧化反应，作为脱硫反应的促进剂。氩气中氢含量超过100%会形成纳米级的环状缺陷，并破坏薄膜的连续性和均匀性。在氢含量为20% - 80%的范围内进行硫化退火后，最终获得了具有高结晶度和近乎完美硫/钼原子比的连续MoS₂薄膜。这种深刻的理解揭示了氢在MoS₂的CVD生长中的关键作用，并为二维材料的可控合成铺平了道路。
