Seminarium Fizyki Ciała Stałego

Hybrid metal-halide perovskites have stormed into the field of semiconductors offering good absorption properties, high photoluminescence yields, an easily tunable bandgap and long carrier lifetimes/diffusion lengths, all together with inexpensive, low-temperature fabrication methods. However, after a decade of research, perovskites are still remaining only "promising candidates" for photovoltaics and LED materials; despite earlier hopes for rapid commercialization, no perovskite-based technology has reached mass market yet.During this seminar, I aim to convince the audience that these fascinating materials still deserve a lot of our attention, as there is much more interesting physics to understand beyond merely optimizing perovskite stability. To start, I will briefly present recent progress in the field and remaining challenges, in particular, fundamental problems being currently under intense debate. Among them are, for example, the origins of the unexpectedly long lifetime of charge carriers, as well as the secret of surprisingly good light-conversion efficiencies despite high density of defects, resulting from solution processing of perovskite films.One possible explanation for both phenomena mentioned above is photo-created carriers being trapped by charges of the lattice. Therefore, the importance of electron-phonon interaction in perovskites will be the focus later in the talk. Revisiting our earlier works on low-temperature excitons in magnetic field with recent results, I will show that reduced mass is significantly enhanced by electron-phonon coupling. Since mass is one of most important band parameters, a complete picture of the interaction between charge carriers and the lattice is fundamental to explaining, then subsequently, tailoring the material properties in a fully controllable wayUwagaSeminarium w trybie zdalnympatrz instrukcja :instrukcja: (pdf file)AttentionThe seminar in the remote modesee instruction :instruction: (pdf file)