Coupling between light and matter strongly depends on the polarization of the electromagnetic field and the nature of excitations in a material. As hybrid perovskites emerge as a promising class of materials for light-based technologies such as LEDs, LASERs, and photodetectors, it is critical to understand how their microstructure changes the intrinsic properties of the photon emission process. While the majority of optical studies have focused on the spectral content, quantum efficiency and lifetimes of emission in various hybrid perovskite thin films and nanostructures, few studies have investigated other properties of the emitted photons such as polarization and emission angle. Here, we use angle-resolved cathodoluminescence microscopy to access the full polarization state of photons emitted from large-grain hybrid perovskite films with spatial resolution well below the optical diffraction limit. Mapping these Stokes parameters as a function of the angle at which the photons are emitted from the thin film surface, we reveal the effect of a grain boundary on the degree of polarization and angle at which the photons are emitted. Such studies of angle- and polarization-resolved emission at the single grain level are necessary for future development of perovskite-based flat optics, where effects of grain boundaries and interfaces need to be mitigated.

中文翻译：

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用于光子技术的混合钙钛矿发射的角分辨偏振测量

光与物质之间的耦合在很大程度上取决于电磁场的极化和材料中激发的性质。随着混合钙钛矿成为 LED、激光和光电探测器等基于光的技术的一种有前途的材料，了解它们的微观结构如何改变光子发射过程的固有特性至关重要。虽然大多数光学研究都集中在各种杂化钙钛矿薄膜和纳米结构中的光谱含量、量子效率和发射寿命，但很少有研究调查发射光子的其他特性，如偏振和发射角。这里，我们使用角度分辨阴极发光显微镜来获取从大晶粒混合钙钛矿薄膜发射的光子的全偏振态，其空间分辨率远低于光学衍射极限。将这些 Stokes 参数映射为光子从薄膜表面发射的角度的函数，我们揭示了晶界对偏振度和光子发射角度的影响。这种在单晶粒水平上进行角度和偏振分辨发射的研究对于未来基于钙钛矿的平面光学器件的发展是必要的，其中需要减轻晶界和界面的影响。我们揭示了晶界对偏振度和光子发射角度的影响。这种在单晶粒水平上进行角度和偏振分辨发射的研究对于未来基于钙钛矿的平面光学器件的发展是必要的，其中需要减轻晶界和界面的影响。我们揭示了晶界对偏振度和光子发射角度的影响。这种在单晶粒水平上进行角度和偏振分辨发射的研究对于未来基于钙钛矿的平面光学器件的发展是必要的，其中需要减轻晶界和界面的影响。