利用太赫兹(THz)时域光谱技术测量了CuS纳米粒子与聚乙烯粉末混合体系在THz波段的光谱响应,然后采用有效介质理论计算得出纯CuS纳米粒子在该波段的吸收系数、复介电常数和复电导率等光学常数,并且分别运用Lorentz色散理论和Durde-Smith模型对该材料的复介电常数和复电导率进行理论上的模拟计算,所得结果与实验符合很好,最后还得到了晶格振动频率、载流子散射时间等THz重要参数.研究结果对揭示CuS纳米结构的材料性能、物理效应和潜在应用等方面具有重要参考价值.
The spectral response of the mixture composed of CuS nanoparticles and polyethylene powder was measured by the terahertz time-domain spectroscopy ( THz-TDS ). The low-frequency optical properties of pure CuS nanoparticles, including absorption coefficient,complex dielectric constants as well as conductivity,were calculated by the effective medium theory. The Lorentz theory of dielectric response and the Drude-Smith model of conductivity provide good fits on the measured dielectric function as well as conductivity,respectively. In addition,some terahertz optical properties,such as the frequency of the lattice vibration and the time constant for the carrier scattering,are also obtained by the fitting. Our investigation could help to reveal the material properties in the terahertz range and to find out the promising physical effect for special application.