A first principles perspective on metal halide perovskites: Challenges, results, and surprises

Metal halide perovskites are a family of energy materials with record-breaking performance in applications ranging from solar cells to X-ray scintillators. However, lead-based halide perovskites – the star materials of the field – suffer from poor stability and the toxicity and scarcity of some of their constituting elements. To overcome these challenges, a plethora of halide perovskite-type materials have been proposed, synthesized, and characterized. This broad range of materials can accommodate dozens of different ions and molecules, giving rise to widely varying chemical and physical properties, and allowing to gain fine-grained control over optoelectronic and transport properties. At the same time, this diversity combined with the need to account for strong spin-orbit interactions and temperature effects, poses significant challenges to first principles numerical modelling techniques.

In this seminar I will present two lines of research in my group. In the first part I will showcase our recent progress in calculating accurate band gaps and optical properties of a wide range of metal halide perovskites using Green’s function-based many-body perturbation theory. In the second part, I will talk about my perspective on tuning and tailoring properties of halide perovskites through chemical substitution, dimensional reduction, hydrostatic pressure, and epitaxial strain.