二维二硒化铂薄膜光学性质的椭偏研究  

Ellipsometry Study on Optical Properties of Two-Dimensional Platinum Selenide Film

作　　者：魏铭洋 连洁 姜清芬 张裕 王宸琳 王月明 许镇 Wei Mingyang;Lian Jie;Jiang Qingfen;Zhang Yu;Wang Chenlin;Wang Yueming;Xu Zhen(School of Information Science and Engineering,Shandong Provincial Key Laboratory of Laser Technology and Application,Shandong University,Qingdao,Shandong 266235,China)

机构地区：[1]山东大学信息科学与工程学院,山东省激光技术与应用重点实验室,山东青岛266235

出　　处：《中国激光》2021年第12期172-181,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(12074214);国家重点基础研究发展计划(2015CB921003);山东省重点研发计划(2017GGX201008)。

摘　　要：近年来,二维二硒化铂(PtSe_(2))由于其独特的性质,在锁模激光器、光电探测器、太阳能电池等领域均表现出巨大的应用潜力,引起了科研人员的广泛兴趣。本实验使用化学气相沉积法,在蓝宝石衬底上生长出不同层数的PtSe_(2)薄膜。使用原子力显微镜和拉曼光谱仪对样品的表面形貌和拉曼振动模式进行研究。吸收光谱表明,PtSe_(2)具有随着层数增加而减小的带隙。使用椭圆偏振光谱仪对样品的光学常数进行表征,结果表明,PtSe_(2)的光学常数与厚度有明显的相关性。使用变温椭偏光谱仪分析温度对PtSe_(2)光学常数的影响,并得到不同波长下的热光系数。本实验结果可以为基于PtSe_(2)的光电器件的设计和优化提供参考。Objective Recently,two-dimensional materials,particularly transition metal sulfides,have attracted broad attention in the field of optoelectronics because of their unique properties.Platinum diselenide(PtSe_(2))is a new type of transition metal sulfide material with unique features,such as adjustable bandgap and high carrier mobility,that has excellent potential for saturable absorbers,photodetectors,and photovoltaic cells.It is necessary to study the variation of PtSe_(2)optical properties with the number of layers,which is essential for designing and optimizing related devices.Moreover,it is also valuable to study the change in the refractive index of PtSe_(2)films with temperature in practical applications.In this work,PtSe_(2)films with two,four,and six layers were grown on sapphire substrates using the chemical vapor deposition method.The optical properties of PtSe_(2)with different thicknesses,including optical bandgap,refractive index,extinction coefficient,dielectric function,and thermooptical coefficient,were investigated using the spectrophotometer and spectroscopic ellipsometry.This work can guide the design and optimization of PtSe_(2)-based optical modulation devices.Methods The synthesis method of PtSe_(2)films used in this work is the three-zone temperature-controlled chemical vapor deposition method(Fig.1).PtSe_(2)films with two,four,and six layers were grown on sapphire substrates by controlling the growth time.The thickness and surface morphology of the samples were confirmed using atomic force microscopy.The Raman vibration patterns of samples with different layer numbers were investigated using Raman spectroscopy.The samples\absorption spectrum was obtained using the spectrophotometer,and the optical bandgap of the samples was obtained using the Tauc formula.The optical constants and dielectric functions of PtSe_(2)with different layer numbers were obtained using spectroscopic ellipsometry.Three Tauc-Lorentz oscillators were used to describe the dielectric function of the PtSe_(2)films during

关 键 词：材料 光学性质 二维材料 椭圆偏振 光学常数 热光系数 

分 类 号：O484.41[理学—固体物理]