Exploring the Optical, Electrical and Structural Properties of Halide Perovskites under Extreme Conditions

The extraordinary properties of hybrid halide perovskites with energy conversion efficiency now exceeding 20% caused an intense research in their application in photovoltaic devices. These materials have exceptional properties including high carrier mobility, long diffusion lengths, and their success in photovoltaic applications is in part based on a simple and affordable fabrication. But what are the underlying principles for this unique set of properties? This project will explore these principles by looking at the optical, electrical and structural response under extreme experimental conditions by means of various spectroscopic methods, photoconductivity and thermal expansion, also subject to high magnetic fields. This enables us to unveil the charge carrier dynamics over a large range of time and length scales, and to address the question how the change in geometrical arrangement of the crystal structure with decreasing temperature alters these properties. The combination between material development and our innovative combined experimental approach does not only offer the possibility to gain fundamental knowledge on the intrinsic properties of these emerging materials but is also expected to contribute to the design and the improvement of devices based on these new materials to generate clean, efficient and sustainable energy at low cost.