Research on Halide Perovskites (HaPs) experienced a surge in the past half dozen years due to the breakthrough success in optoelectronics including a new archetype of solar cells. The focus of the symposium will be on the underpinnings of the materials properties (photovoltaic, electroluminescent, dielectric/ ferroelectric/ferroelastic, thermoelectric, electrochemical, etc.) in the bulk material, at the surface, and at the interfaces to other material systems. The versatile performance of HaPs has been ascribed to their remarkable semiconductor properties (e.g. long-lived charge carriers, near unity internal quantum yield, defect tolerance, self-healing, etc.). While the remarkable structural and optoelectronic properties do not stand out as unusual if looked at individually, the combination of these traits in one material has put HaPs in the spotlight within the fields of physics, chemistry and materials science. To facilitate a comprehensive debate, the symposium will span over various topic areas covering experimental and theoretical approaches: One part of the symposium will focus on thin-film and crystal synthesis, meso- and nanoscale structuring, and the achievement of lower dimensional systems, all of which includes crystal theory, nucleation mechanisms and materials design. The other part of the symposium will focus on the characterization, analysis and understanding of the optoelectronic properties. Among these topics are theoretical ab-initio calculations, the description of ion, charge and phonon dynamics, defect science, grain-boundary phenomena, and the role of surfaces and interfaces for charge and energy transfer. The symposium will hence cover a broad spectrum of basic science, from macro- and microscopic aspects down to quantum phenomena and nanoscience, for researchers who work on HaP materials and (opto)electronics. Beyond this focus, perovskite-related materials with similar properties will be featured along with new analysis methods in theory and experiment.

chemical composition compound defects electronic material electronic structure electron-phonon interactions optical properties optoelectronic phase transformation photovoltaic