The knowledge of the carrier dynamics in nanostructures is of fundamental importance for the development of (opto)electronic devices. This is true for semiconducting nanostructures as well as for plasmonic nanoparticles (NPs). Indeed, improvement of photocatalytic efficiencies by combining semiconductor and plasmonic nanostructures is one of the reasons why their ultrafast dynamics are intensively studied. In this work, we will review our activity on ultrafast spectroscopy in nanostructures carried out in the recently established EuroFEL Support Laboratory. We have investigated the dynamical plasmonic responses of metal NPs both in solution and in 2D and 3D arrays on surfaces, with particular attention being paid to the effects of the nanoparticle shape and to the conversion of absorbed light into heat on a nano-localized scale. We will summarize the results obtained on the carrier dynamics in nanostructured perovskites with emphasis on the hot-carrier dynamics and in semiconductor nanosystems such as ZnSe and Si nanowires, with particular attention to the band-gap bleaching dynamics. Subsequently, the study of semiconductor-metal NP hybrids, such as CeO$_2$-Ag NPs, ZnSe-Ag NPs and ZnSe-Au NPs, allows the discussion of interaction mechanisms such as charge carrier transfer and F{\"o}rster interaction. Finally, we assess an alternative method for the sensitization of wide band gap semiconductors to visible light by discussing the relationship between the carrier dynamics of TiO$_2$ NPs and V-doped TiO$_2$ NPs and their catalytic properties.

中文翻译：

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半导体和等离子体纳米结构及其混合物的超快光谱学。

纳米结构中载流子动力学的知识对于（光）电子器件的发展至关重要。这适用于半导体纳米结构以及等离子体纳米粒子 (NP)。事实上，通过结合半导体和等离子体纳米结构来提高光催化效率是对其超快动力学进行深入研究的原因之一。在这项工作中，我们将回顾我们在最近成立的 EuroFEL 支持实验室开展的纳米结构超快光谱学方面的活动。我们研究了金属纳米粒子在溶液中以及表面上的 2D 和 3D 阵列中的动态等离子体响应，特别注意纳米粒子形状的影响以及在纳米局部尺度上将吸收的光转化为热的影响。我们将总结在纳米结构钙钛矿中获得的载流子动力学结果，重点是热载流子动力学和半导体纳米系统（如 ZnSe 和 Si 纳米线），特别关注带隙漂白动力学。随后，对半导体-金属 NP 杂化物的研究，如 CeO$_2$-Ag NPs、ZnSe-Ag NPs 和 ZnSe-Au NPs，允许讨论诸如电荷载流子转移和 F{\"o}rster 等相互作用机制。最后，我们通过讨论 TiO$_2$ NPs 和 V 掺杂 TiO$_2$ NPs 的载流子动力学及其催化性能之间的关系，评估了一种使宽带隙半导体对可见光敏感的替代方法。