二硫化钨薄膜的制备及发光性能

Preparation and Luminescence Properties of WS2 Thin Films

采用常压化学气相沉积(APCVD)法在SiO_(2)/Si(300 nm)衬底上制备最大尺寸为74.22μm的多层二硫化钨(WS_(2))薄膜,并在蓝宝石衬底上合成边缘清晰、形状规则、最大尺寸为41.89μm的WS_(2)薄膜.通过光学显微镜(OM)、扫描电子显微镜(SEM)、Raman光谱仪和光致发光谱仪(PL)等对制备的样品进行表征,并结合样品的形貌尺寸分析生长温度、钨源和氯化钠(NaCl)用量比例、不同衬底等实验参数对生长WS_(2)薄膜的影响.实验结果表明:温度对APCVD生长WS_(2)薄膜影响最大,高温有助于生长高结晶质量的WS_(2)薄膜,温度越高,薄膜形状越规则;在最佳温度下,波数差越小,薄膜层数越少,晶粒缺陷越少,发光强度越高;不同温度对应的钨源和氯化钠用量比不同,加入适量的氯化钠有助于提高反应系统中钨源的过饱和度,促进反应顺利进行,更有利于WS_(2)薄膜生长;不同衬底制备WS_(2)薄膜的生长系统所需生长温度不同,在相同的实验条件下,蓝宝石衬底上所需的生长温度更高.

Multilayer triangular WS_(2) films with a maximum size of 74.22μm were prepared by atmospheric chemical vapor deposition(APCVD)method on SiO_(2)/Si(300 nm)substrate,and WS_(2) films with clear edge,regular shape and a maximum size of 41.89μm were synthesized on sapphire substrate.The prepared samples were characterized by optical microscope(OM),scanning electron microscope(SEM),Raman spectrometer and photo-emission spectrometer(PL).Combined with the morphology and size of the sample,the effects of experimental parameters such as growth temperature,dosage ratio of tungsten source and sodium chloride,and different substrates on the growth of WS_(2) thin films were analyzed.The experimental results show that temperature has the greatest influence on the growth of WS_(2) films by APCVD,and high temperature is conducive to the growth of WS_(2) films with high crystal quality.The higher the temperature is,the more regular the film shape is.At the optimum temperature,the smaller the wave number difference is,the fewer the film layers are,the fewer the grain defects are,and the higher the luminous intensity is.The dosage ratio of tungsten source and sodium chloride corresponding to different temperatures is different.The addition of proper amount of sodium chloride can improve the supersaturation of tungsten source in the reaction system,promote the smooth progress of the reaction,and is more conducive to the growth of WS_(2) thin film.The growth temperature required by the growth system for preparing WS_(2) thin films on different substrates is different,and the growth temperature required on sapphire substrate is higher under the same experimental conditions.