Scattering Interfaces with Tailored Disorder andBinary Profiles

按需提供散射特性的光学接口是一个由来已久的愿景。这样的接口将在太阳能电池或有机发光二极管等光电子元件构成参考实例的大量设备中使用。许多此类应用中的挑战是，不仅要在单个波长，而且要在扩展的光谱域中定制接口，以实现最佳操作。这排除了对高度有序结构的考虑，而不是对无序结构的提示。然而，需要的不是纯粹的随机性，而是具有量身定做的相关性的无序，以揭示光散射中无序的全部潜力。此外，实验制备的无序本质上包含它们各自的制造方法所固有的某些关联。即使对于在很大程度上允许调谐无序的方法，对于无序可以被调谐的范围总是存在内在的限制，这抑制了真正的任意定制无序。在SPP的第二个资助期，我们努力建立理论和可扩展的实验工具，以获得具有期望的光散射响应的大面积无序或无序超均匀界面。特别是，我们的方法使我们能够研究独立定制的障碍的多个接口的堆叠，以克服单个接口的固有限制。这释放了更多的自由度，便于实现真正的任意光学响应。在第一个资助期，调查了具有连续高度轮廓的定制的无序界面。从理论上讲，我们可以确定频谱功率密度作为一个关键参数。在实验上，通过过度生长无序的球体单层来制备大面积的无序界面。单分子层是通过一种独特的自下而上的技术沉积的，该技术允许精确调整球体的横向排列和尺寸分布。第二个资助期的关键因素是考虑使用双界面，即纳米孔或磁盘层，而不是连续界面，这具有重大优势。理论上，我们寻求开发半解析方法来处理大调制的无序纹理，并继续利用逆向建模和形状优化。在实验方面，我们专注于探索二元表面纹理，因为这样的系统允许选择材料的灵活性和获得具有独立定制界面的多堆栈结构的简单性。无序的接口将被集成到太阳能电池或OLED等功能较大的设备中。特别是在这些设备中，我们预计多个独立的无序接口会带来回报，因为不同的接口可以处理不同的请求功能。此外，通过堆叠的多个无序界面，我们可以从根本上探索无序系统在多大程度上被调谐到随机性，同时仍保持一定的相关性。

Optical interfaces that offer scattering properties on-demand are a long-standing vision. Such interfaces would find use in a plethora of devices for which optoelectronic elements such as solar cells or OLEDs constitute referential examples. The challenge in many of these applications is to tailor the interfaces towards optimal operation not just at a single wavelength but rather in an extended spectral domain. This precludes the consideration of highly ordered structures and prompts instead for disorder structures. However, not sheer randomness but disorder with tailored correlations are needed to unfold the full potential of disorder in light scattering. Furthermore, experimentally prepared disorder intrinsically contains certain correlations inherent to their respective fabrication method. Even for methods that allow to tune disorder to a large extend there always exist intrinsic limitations on the range the disorder can be tuned, which inhibits truly arbitrary tailored disorder.In this second funding period of the SPP, we endeavor to establish theoretical and scalable experimental tools to obtain large area disordered or disordered hyperuniform interfaces with a desired light scattering response. In particular, our approach enables us to investigate stacks of multiple interfaces of independently tailored disorder to overcome inherent limitations of the individual interface. This unlocks additional degrees of freedom facilitating truly arbitrary optical responses. In the first funding period, tailored disordered interfaces with a continuous height profile were investigated. Theoretically, we could determine the spectral power density as a key parameter. Experimentally, large-area disordered interfaces were prepared by overgrowing a disordered monolayer of spheres. The monolayer was deposited by a unique bottom-up technique that allows precise tuning of the lateral arrangement and size distribution of the spheres. The key element in this second funding period is the consideration of binary interfaces, i.e. nanohole or -disk layers, instead of continuous interfaces, which has major advantages. Theoretically, we seek to develop semi-analytical methods to address disordered textures with large modulations and proceed to exploit inverse modelling and shape optimization. Experimentally, we focus on exploring binary surface textures as such systems allow flexibility in choice of material and simplicity in obtaining a multi-stack structure with independently tailored interfaces. The disordered interfaces will be integrated into functional large-area devices such as solar cells or OLEDs. Particularly in these devices we expect multiple independent disordered interfaces to pay-off, as different requested functionalities can be handled with different interfaces. Moreover, with stacks of multiple disorder interfaces we can fundamentally probe the extent to which disordered systems are tuned towards randomness while still preserving certain correlations.