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大尺寸WSe2薄膜可控制备及其光学特性

发表时间:2017-09-30  浏览量:1421  下载量:675
全部作者: 项昂之,李孟林,夏莉,李玉红
作者单位: 兰州大学核科学与技术学院;复旦大学高分子科学系
摘 要: 探讨常压化学气相沉积(chemical vapor deposition,CVD)法下生长温度、钨源量及其与衬底之间的距离对WSe2薄膜生长的影响。通过调控,在SiO2/Si衬底上制备出最大尺寸为50 μm的单层WSe2三角形薄膜、150 μm的单层WSe2六边形薄膜及0.5 cm×0.5 cm的大面积连续WSe2少层薄膜,并用光学显微镜、拉曼光谱与光致发光(photo-luminescence,PL)谱分别对单层、双层、三层结构的WSe2薄膜进行表征,观测到其峰位随着层数的增加而红移,表明随着层数的减小,WSe2薄膜的光学带隙变大,证实了WSe2从体结构转化为单层时,其带隙由间接带隙转变为直接带隙。
关 键 词: 低维无机非金属材料;二硒化钨;化学气相沉积;生长机理;光致发光;拉曼
Title: Large-sized WSe2 film: its controllable preparation and optical properties
Author: XIANG Angzhi, LI Menglin, XIA Li, LI Yuhong
Organization: The School of Nuclear Science and Technology, Lanzhou University; Department of Macromolecular Science, Fudan University
Abstract: This paper investigated the effects of temperature, the quantity of precursor source tungsten and the distance between substrate and tungsten in atmospheric pressure chemical vapor deposition (CVD) on the growth of WSe2 films. Through the regulation, the mono-layer triangular WSe2 films with the maximum side length of 50 μm, the hexagon mono-layer WSe2 films with the maximum side length of 150 μm, and the large-sized few-layer WSe2 films of 0.5 cm×0.5 cm on the SiO2/Si substrates were developed. The mono-, double- and triple-layered WSe2 films were characterized by optical microscopy, Raman spectra and photo-luminescence (PL) spectra. Besides, the band structure change of WSe2 film transforming from bulk to single layer film was theoretically analyzed. The observed peak was red shifted with the increase of the number of layers, which shows that the optical band gap of the WSe2 films increases with the decrease of the number of layers. It proves that the WSe2 material structure is transformed from bulk into monolayer, the band gap is transformed from indirect band gap into direct band gap.
Key words: This paper investigated the effects of temperature, the quantity of precursor source tungsten and mechanism; photo-luminescence; Raman
发表期数: 2017年9月第18期
引用格式: 项昂之,李孟林,夏莉,等. 大尺寸WSe2薄膜可控制备及其光学特性[J]. 中国科技论文在线精品论文,2017,10(18):2094-2102.
 
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