PP 2196: Illuminating Building Block Evolution of Metal-Halide Perovskite Semiconductors from Solutions to Thin Films

The overall goal of this project is to gain fundamental understanding on the structural, electronic, and optical properties of metal-halide complexes in solutions and to follow their evolution towards the formation of crystalline semiconductors through low-dimensional intermediates. We will tackle these research questions in an interdisciplinary framework at the boundary between chemistry and physics adopting strongly intertwined experimental and theoretical approaches.
The coordination chemistry of halido-plumbate complexes in different types of solvents will be investigated systematically with a combination of state-of-the-art X-ray spectroscopy techniques, including extended X-ray absorption fine structure, X-ray absorption near-edge structure, and X-ray diffraction (XRD). Geometries, structures, and binding strengths of these systems will be disclosed in combination with density-functional theory (DFT) calculations. In this way, we will be able to rationalise how solvents influence the formation of intermediate solvate phases. We will further identify and rationalise the spectral fingerprints of metal-halide complexes in solution by means of (time-resolved) optical spectroscopy complemented by first-principles calculations based on many-body perturbation theory (MBPT). Finally, the evolution of solution complexes as 0D building blocks of hybrid metal-halide perovskites towards low-dimensional crystalline intermediates and solid-state semiconductors will be followed by a combination of in-situ optical monitoring, based on XRD and X-ray fluorescence, and novel correlative optical and core-level techniques that will be developed within the project. These studies will be complemented by DFT and MBPT calculations on the crystalline intermediates, giving access to electronic, optical and core-level excitations with state-of-the-art accuracy.
The outcomes of this project will provide unprecedented insight into the fundamental processes leading to the formation of hybrid metal-halide perovskite semiconductors from solution complexes.