Eugenia Vasileiadou

In our urgent transition towards renewable energy sources, optoelectronic devices are key in establishing clean energy-efficient optical sources. Solution-processable semiconductors have gained a central role in the development of contemporary and next-generation electronics as a result of several advantages, including facile syntheses, deposition and use of flexible substrates, while maintaining excellent optical properties. Herein, I will discuss my work on two, prominent classes of solution-processable materials: bulk, metal halide perovskites and metal chalcogenide nanocrystals. While an initial perception has been gained on the synthetic chemistry and engineering of devices for the mentioned materials, there is still a lack of systematic design principles for harnessing their synthesis-property relationships for next-generation, commercial applications. Firstly, I will discuss advancing the rational design of sophisticated 2D halide perovskites and perovskite-related frameworks for optoelectronic applications. The synthesis, characterization and stability studies of several, novel families of hybrid metal halide perovskites will be presented by tailoring the structure type through the organic layers ranging from standard, aliphatic organic cations to organic layers with functional groups to even more sophisticated molecules that are luminophores. Next, I will focus on tailoring the inorganic components of the 2D perovskite structure through increasing the electronegativity of halide from iodide to bromide, as well as separately reporting on how the crystal chemistry and thin film properties of thick-layer perovskites evolve with the substitution of the lead metal center with tin. In parallel, I will present progress on the synthesis-property relationships of non-standard, metal chalcogenide nanocrystal semiconductors. I will talk on my work on enhancing the surface chemistry of CdSe nanomaterials by introducing novel, organochalcogen functional ligands that provide intimate electronic contact and alter the photophysical properties. Lastly, I will talk about our recent progress on mapping the growth mechanism and defect tolerance in ultrasmall and ultrabright HgTe nanocrystals, which are extraordinary bright infrared-emitting materials exhibiting quantum yield >80%, rendering them as attractive candidates for shortwave-infrared device applications.