物理学报2016，Vol.65Issue(12)：128101-1-128101-5,5.DOI:10.7498/aps.65.128101
一种简单的化学气相沉积法制备大尺寸单层二硫化钼∗
Synthesis of large size monolayer MoS2 with a simple chemical vap or dep osition
摘要
Abstract
Monolayer molybdenum disulfide (MoS2) has recently aroused the great interest of researchers due to its direct-gap property and potential applications in electronics, catalysis, photovoltaics, and optoelectronics. Chemical vapor deposition (CVD) has been one of the most practical methods of synthesizing large-area and high-quality monolayer MoS2. However, The process of preparation is complex and cumbersome. Here we report that high-quality monolayer MoS2 can be obtained through using sulfurization of MoO3 by a simple and convenient CVD on sapphire substrates. <br> The substrate cleaning is simplified. Substrates are cleaned in detergent solution, deionized water and acetone without sopropanol or piranha solution (H2SO4/H2O2=3:1) in sequence, avoiding their potential dangers . The MoO3 powder (Alfa Aesar, 99.995%, 0.02 g) is placed in an alumina boat, and a sapphire substrate is faced down and is placed 6 cm away from MoO3 powder in the same boat. The sapphire substrate is placed in the center of the heating zone of the furnace. Another alumina boat containing sulfur powder (Alfa Aesar, 99.999%, 0.2 g) is placed upstream with respect to the gas flow direction in the low temperature area. We adopt an atmospheric pressure chemical vapor deposition method, so it does not require a vacuum process. After 30 min of Ar purging, the furnace temperature is directly increased from room temperature to 800 ◦C in 30 min, reducing the heating steps. After 60 min, the furnace is cooled down naturally to room temperature. Optical microscopy (OM) images, Raman spectra and photoluminescence (PL) are all obtained by confocal Raman microscopic system (LabRAM HR Evolution). From the OM images, we can see that isolated islands (triangles) have edge lengths up to 50 µm, which is far larger than that grown by micromechanical exfoliation. The color of the triangles is uniform, which has a strong contrast with the substrate. We can obtain a preliminary result that the sample is a uniform monolayer MoS2. Raman spectra are collected for MoS2 samples on sapphire substrates. Two typical Raman active modes can be found: E12g at 386.4 cm−1 and A1g at 406 cm−1 (∆=19.6 cm−1), which correspond to single-layered MoS2 sample. Raman mapping shows that the sample is a uniform monolayer MoS2. The PL spectrum of MoS2 shows a pronounced emission peak at 669 nm, which is consistent with other reported results for MoS2 thin sheets obtained from exfoliation methods. When the layer number of MoS2 decreases, with its bandgap transforming from indirect to direct one, the fluorescence efficiency will be significantly enhanced. So the results further prove that the sample is high-quality monolayer MoS2.关键词
单层二硫化钼/化学气相沉积/拉曼光谱/光致发光谱Key words
monolayer MoS2/chemical vapor deposition/Raman spectroscopy/photoluminescence spectroscopy引用本文复制引用
董艳芳,何大伟,王永生,许海腾,巩哲..一种简单的化学气相沉积法制备大尺寸单层二硫化钼∗[J].物理学报,2016,65(12):128101-1-128101-5,5.基金项目
国家自然科学基金(批准号:61335006,61527817,61378073)和北京市科学技术委员会(批准号：Z151100003315006)资助的课题.@@@@* Project supported by the National Natural Science Foundation of China (Grant Nos.61335006,61527817,61378073) and the Beijing Municipal Science and Technology Commission, China (Grant No. Z151100003315006) （批准号:61335006,61527817,61378073）
