Liu Pengyu, Luo Tao, Xing Jie, Xu Hong, Hao Huiying, Liu Hao, Dong Jingjing
School of Science, China University of Geosciences, Beijing, 100083, China.
Nanoscale Res Lett. 2017 Oct 3;12(1):558. doi: 10.1186/s11671-017-2329-9.
High-quality WS film with the single domain size up to 400 μm was grown on Si/SiO wafer by atmospheric pressure chemical vapor deposition. The effects of some important fabrication parameters on the controlled growth of WS film have been investigated in detail, including the choice of precursors, tube pressure, growing temperature, holding time, the amount of sulfur powder, and gas flow rate. By optimizing the growth conditions at one atmospheric pressure, we obtained tungsten disulfide single domains with an average size over 100 μm. Raman spectra, atomic force microscopy, and transmission electron microscopy provided direct evidence that the WS film had an atomic layer thickness and a single-domain hexagonal structure with a high crystal quality. And the photoluminescence spectra indicated that the tungsten disulfide films showed an evident layer-number-dependent fluorescence efficiency, depending on their energy band structure. Our study provides an important experimental basis for large-area, controllable preparation of atom-thick tungsten disulfide thin film and can also expedite the development of scalable high-performance optoelectronic devices based on WS film.
通过常压化学气相沉积在硅/二氧化硅晶圆上生长出了高质量的二硫化钨薄膜，其单畴尺寸可达400微米。详细研究了一些重要制备参数对二硫化钨薄膜可控生长的影响，包括前驱体的选择、管内压力、生长温度、保温时间、硫粉用量和气体流速。通过在一个大气压下优化生长条件，我们获得了平均尺寸超过100微米的二硫化钨单畴。拉曼光谱、原子力显微镜和透射电子显微镜提供了直接证据，表明该二硫化钨薄膜具有原子层厚度以及高质量的单畴六方结构。并且光致发光光谱表明，二硫化钨薄膜呈现出明显的层数依赖荧光效率，这取决于它们的能带结构。我们的研究为大面积、可控制备原子级厚度的二硫化钨薄膜提供了重要的实验依据，也能够加速基于二硫化钨薄膜的可扩展高性能光电器件的发展。
