摘要
为研究激光诱导对二氧化钒光学性质的具体影响,采用磁控溅射技术制备了二氧化钒薄膜。利用原子力显微镜和X射线衍射仪对样品进行表征,发现其具有良好的平整度及致密均匀的结构,是纯相二氧化钒(M)薄膜,并且在透过率-温度变化曲线中观察到了典型的热滞回线。采用透/反射强度扫描系统研究了二氧化钒薄膜的光学特性,实验结果表明,在飞秒激光诱导下样品经历了非线性吸收过程、相变过程、稳态过程和损伤过程,非线性吸收过程由双光子吸收效应主导而相变过程与激光热效应息息相关。进一步研究发现,随着激光重复频率增加,增强的热效应导致其相变开启阈值和损伤阈值明显下降。
Semiconductor-metal phase transition in metal oxides have attracted much attention due to their scientific significance in condensed matter physics and their possibilities in a variety of applications.During the last half century,experimental and theoretical studies on phase transition mechanism have been discussed.Vanadium dioxide(VO_(2))has attracted much attention due to its phase transition properties at room temperature.The VO_(2) phase transition can be triggered by a variety of excitations,such as thermal,electrical,optical,magnetic field,and strain,and because the phase transition process is reversible and its optical properties change significantly,it is widely used in optical switches,smart windows,optical storage,and laser protection.With the rapid development of femtosecond laser technology,more and more researchers are involved in the study of laser-material interactions.The control of VO_(2) phase transition on ultrafast time scale using optical means will benefit its potential applications in memory devices,ultrafast optical switches and bistable optoelectronic devices.Firstly,we briefly introduce the basic properties of VO_(2).The material undergoes a phase transition at room temperature(~68℃),which is reversible and non-destructive.Stimulated by external conditions,VO_(2) transforms from a monoclinic semiconducting phase(P2_(1)/c)to a tetragonal rutile phase(P42/mnm)with a distortion of the lattice structure,accompanied by a change in electrical resistance of about four orders of magnitude and a consequent change in its optical properties.A common method for inducing semiconductor-metal phase transition is thermal triggering.Below the phase transition temperature,VO_(2) is a semiconducting phase with a high transmittance,and when the temperature is heated above 68℃,VO_(2) changes into a metallic phase with abrupt changes in its optical properties such as refractive index,transmittance,and reflectance.The phase transition can also be triggered on sub-picosecond time scales under femtosecond la
作者
王梓鑫
董宁宁
王路路
曹逊
王俊
WANG Zixin;DONG Ningning;WANG Lulu;CAO Xun;WANG Jun(Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2022年第10期112-119,共8页
Acta Photonica Sinica
基金
国家自然科学基金(No.61975221)。
