Optical Properties of CuI, Doped CuI and CuI-Based Alloys

该项目的目的是详细研究卤化铜和卤化铜基合金的光学性质。特别感兴趣的是卤化物组合物对光学性质的影响，例如介电函数和基本光学跃迁的性质，以及发射和声子性质。为此，将通过各种光学方法来研究二元化合物以及三元和四元合金，例如(空间分辨的)椭圆偏振光谱、(微)反射率、拉曼光谱、时间和空间分辨的光致发光光谱和激发光谱。由于这种材料系统中激子振子强度很大，所以发生了很强的光-物质相互作用。因此，必须使用激子-极化子来解释光谱，而不是通常使用的激子-极化子复合图像。我们将研究合金成分对大块晶体中激子振子强度的影响，从而对激子-极化子色散以及相关的分支间和分支内散射过程的影响，这将使我们对大块晶体中的激子-极化子物理有更深入的了解。

The aim of the project is a detailed investigation of the optical properties of copper halides and copper halides-based alloys. Of special interest are the impact of the halide composition on the optical properties, such as the dielectric function and the properties of the underlying optical transitions, as well as the emission and phonon properties. For this purpose, binary compounds as well as ternary and quaternary alloys will be investigated by means of a variety of optical methods, e.g., (spatially-resolved) spectroscopic ellipsometry, (micro) reflectivity, Raman spectroscopy, time- and spatially-resolved photoluminescence spectroscopy and excitation spectroscopy. Due to the large exciton oscillator strength in this material system, a strong light-matter interaction takes place. Thus, instead of the typically used picture of a recombination of excitons, exciton-polaritons have to be used for the interpretation of the optical spectra. The impact of the alloy composition on the exciton oscillator strength and thus on the exciton-polariton dispersion as well as the related inter- and intrabranch scattering processes in bulk crystals will be investigated, which allows a deeper insight into the exciton-polariton physics in bulk crystals in general.