Seminarium Fizyki Ciała Stałego

In the last few years, hybrid (organic-inorganic) perovskite solar cells (PSCs) have undergone exceptionally rapid advancements in power conversion efficiencies, quickly reaching the values, which took silicon solar cells decades of development. Moreover, the great potential of perovskites for applications in other optoelectronic devices, such as photodetectors, lasers and light-emitting diodes, or microcavity structures operating in the regime of strong light-matter interaction, has recently been demonstrated. High efficiencies and superior performance of perovskite-based devices is due to their high absorption coefficient, relatively low exciton binding energies, and long diffusion length and lifetime of carriers[1]. However, despite all these advantages and the resulting huge interest in perovskite structures, several serious challenges concerning the environmental stability of such devices remain to be addressed for their commercial applications and cost-competitive deployment at a large scale. In particular, it is well established that the exposure of perovskite films to moisture and oxygen leads to material degradation within days[2][3].In this work, we analyzed the degradation dynamics under different environmental conditions for so called multidimensional perovskite films (i.e., materials comprised of 2D and 3D perovskites – 2D/3D PVSK) and compared it with reference 3D perovskite samples. As expected, the study showed that our novel modification resulted in a significantly higher stability, with the characteristic degradation times for 2D/3D PVSK samples to be 5 times longer than those measured for reference 3D PVSK films. Moreover, we observed reversible and irreversible water intercalation effects (hydration and dehydration processes) in perovskite films kept under changing relative humidity. The effects of a partial iodine substitution with bromine in perovskite structure was also investigated. It was found that such a modification suppresses the hydration processes altogether, which is an extremely valuable observation from the point of view of achieving water-resistant perovskite films.[1] S.D. Stranks, et al., Phys. Rev. Appl. 2 (2014) 034007.[2] T. Leijtens, et al., Nat. Commun. 2013 41. 4 (2013) 1–8[3] A. Wincukiewicz, et al., Sol. Energy Mater. Sol. Cells. 230 (2021) 111142.UwagaSeminarium w trybie HybrydowymFaculty of Physics room 0.06link to remote mode:https://zoom.us/j/7218838148szczegóły patrz instrukcja :instrukcja: (pdf file)AttentionThe seminar in the Hybrid modeFaculty of Physics room 0.06for details see instruction :