Insight into the growth behaviors of MoS_(2)nanograins influenced by step edges and atomic structure of the substrate  

作　　者：Shuangyue Wang Ni Yang Mengyao Li Ji Zhang Ashraful Azam Yin Yao Xiaotao Zu Liang Qiao Peter Reece John Stride Jack Yang Sean Li 

机构地区：[1]School of Materials Science and Engineering,UNSW Sydney,NSW 2052,Australia [2]School of Physics,University of Electronic Science and Technology of China,Chengdu 610054,China [3]School of Physics,UNSW Sydney,NSW 2052,Australia [4]School of Chemistry,UNSW Sydney,NSW 2052,Australia

出　　处：《Nano Research》2022年第8期7646-7654,共9页纳米研究（英文版）

基　　金：the financial support from the Australian Research Council Discovery Program(No.DP190103661).

摘　　要：The step edges and intrinsic atomic structure of single-crystal substrate play a critical role in determining the growth pathways of transition metal dichalcogenide(TMD)grains,particularly whether the TMDs will grow into wafer-scale single-crystal or anisotropic nanoribbons.Hereby,we investigate the growth behaviours of the MoS_(2)nanograins on(0001)and()sapphire substrates.On one hand,the step edges formed on the(0001)surface after thermal treatment are found to promote the macroscopic aggregation of MoS_(2)nanograins and to form unidirectional large triangular islands along with the<>steps in the annealing process,while on the pristine(0001)surface,the MoS_(2)nanograins grow into a random network-like pattern.Moreover,oxygen treatment on the substrate can further enhance the growth of MoS_(2)nanograins.Transmission electron microscopy and fast Fourier transform patterns reveal that the substrate could modulate the orientation of MoS_(2)nanograins during their growing process.On the other hand,the MoS_(2)nanograins on the surface could self-assemble into one-dimensional nanoribbons due to the strong structural anisotropy of the substrate.In addition,the ratio of Raman intensities for peaks that correspond to the and A1g phonon modes shows a linear relationship with the grain size due to the change of the“phonon confinement”.Moreover,new peaks located at 226 and 280 cm−1 can be observed in the off-resonant and resonant Raman spectra for the MoS_(2)nanograin samples,respectively,which can be attributed to the scatterings from the edges of as-fabricated MoS_(2)nanostructures.

关 键 词：MoS_(2)nanograins growth behaviors step edges atomic structure Raman spectra evolution UV-vis absorption 

分 类 号：TB383[一般工业技术—材料科学与工程]