Understanding light-triggered charge carrier dynamics on photovoltaic-material surfaces and at interfaces has been a key element and one of the major challenges for the development of real-world energy devices. For this reason, studying charge carrier dynamics at photoactive material surfaces and interfaces have been among the most active areas of research in the last decade [1-4]. More specifically, hybrid organic/inorganic perovskites have recently emerged as an important class of materials and have exhibited remarkable performance in photovoltaics. To further improve their device efficiency, an insightful understanding of the interfacial charge transfer (CT) process is required. Recently, we reported the first direct experimental observation of the tremendous effect that the shape, dimensionality and doping of perovskite nanocrystals (NCs) has on interfacial CT in the presence of a molecular acceptor (4, 5). A dramatic change in CT dynamics at the interfaces of doped and un-doped NCs is recorded. Our results clearly demonstrate that the mechanism of CT is significantly affected by the doping and the shape of NCs. More importantly, the results demonstrate that complexation on the NCs surface acts as an additional driving force not only to tune the CT dynamics but also to control the reaction mechanism at the interface. This observation opens a new venue for further developing perovskite NCs-based applications.

Tracking ultrafast charge carrier dynamics at the interface of perovskite nanocrystals using time-resolved laser spectroscopy

255th National Meeting (2018)

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