Nanocrystals with low size distribution are able to self-assemble into a 3D crystalline structure called colloidal crystals or super/supracrystals. A rather large number of supracrystal specific properties have been achieved showing promising potential applications. Here, we compared intrinsic properties induced by light interacting with fcc supracrystals of hydrophobic metal nanocrystals either deposited on a substrate or dispersed in aqueous solution. We first describe the formation of a dried supracrystal film grown via a heterogeneous process with cracks formed due to the shrinking of the film caused by restriction of its adhesion on the surface. We also describe the method to fabricate hydrophobic supracrystals dispersed in aqueous solution. The optical properties of the thick dried supracrystal film are determined from the wetting layers formed at the bottom of the cracks whereas, for water dispersed suprastructures, both the collective optical photonic mode and absorption of dispersed nanocrystals used as build blocks are observed. Ag nanocrystals used as building blocks in a dried supracrystal film vibrate coherently as atoms in a nanocrystal. However, it is impossible to determine the oscillation period of the whole assembly. Conversely from a dynamic study, the breathing period of the assemblies dispersed in aqueous solution is found to be around 300 ps. Whatever experimental conditions, nanocrystals exposed to light breath coherently in a supracrystal. In aqueous solution, supracrystals behave as nanoheaters.

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与沉积在基质上或分散在水中的超晶体的光相互作用

具有较小尺寸分布的纳米晶体能够自组装成3D晶体结构，称为胶体晶体或超/超晶体。已经获得了相当数量的超晶格特定性能，显示出有希望的潜在应用。在这里，我们比较了由光与疏水金属纳米晶体的fcc超晶体相互作用产生的内在特性，疏水金属纳米晶体要么沉积在基材上，要么分散在水溶液中。我们首先描述通过这是一种异质工艺，由于薄膜的收缩（由于薄膜在表面上的附着力受到限制）而产生了裂纹，因此产生了裂纹。我们还描述了制造分散在水溶液中的疏水超晶体的方法。干燥的超晶体厚膜的光学特性是由裂纹底部形成的润湿层确定的，而对于水分散的超结构，则同时观察到集体光学光子模式和用作构造块的分散纳米晶体的吸收。在干燥的超晶质膜中用作构建单元的Ag纳米晶作为纳米晶中的原子相干振动。但是，不可能确定整个组件的振荡周期。与动态研究相反，发现分散在水溶液中的组件的呼吸时间约为300 ps。无论实验条件如何，暴露于光中的纳米晶体都在超晶体中相干地呼吸。在水溶液中，超晶充当纳米加热器。