The research funded by the ERC Starting Grant addresses a fundamental problem in materials science: how strongly anharmonic lattice dynamics influence the electronic, optical, and transport properties of functional materials. Traditionally, the behavior of semiconductors, ion conductors, and optoelectronic materials has been understood within the harmonic approximation, where atomic vibrations are treated as independent oscillators. However, many technologically relevant materials, such as halide perovskites, solid-state ion conductors, and organic molecular crystals, exhibit significant anharmonicity that cannot be captured by conventional models. This research aims to understand how anharmonic lattice fluctuations modify material properties, enabling new mechanisms for charge transport, defect passivation, and phase stability.
The importance of this research extends far beyond fundamental science, as it directly impacts key technologies in energy, electronics, and sustainability. In optoelectronics, for example, halide perovskites have revolutionized solar cells and light-emitting devices, yet their remarkable performance remains poorly understood due to their highly anharmonic nature. Understanding the role of dynamic disorder and local polar fluctuations in these materials can lead to more efficient, stable, and scalable perovskite-based technologies. Similarly, in energy storage, solid-state ion conductors are essential for next-generation batteries, where fast ionic transport is critical for high-performance electrolytes. This research provides insights into how lattice dynamics facilitate or hinder ion mobility, guiding the design of better solid-state battery materials. Furthermore, in organic molecular crystals, understanding vibrational couplings can improve material stability and electronic properties, influencing applications from flexible electronics to pharmaceutical formulations.
The overall objectives of the project are threefold. First, it aims to develop advanced experimental techniques, particularly time-resolved Raman spectroscopy, to probe anharmonic lattice dynamics with unprecedented precision. This approach allows direct observation of non-equilibrium lattice effects, polaron formation, and self-trapped excitons in real time. Second, the research seeks to establish a theoretical framework that links anharmonic lattice behavior to macroscopic material properties, integrating experimental findings with first-principles calculations and molecular dynamics simulations. Finally, the project aims to apply these insights to improve the performance and stability of real-world materials, guiding the rational design of new semiconductors, solid electrolytes, and molecular crystals with enhanced functionalities. By bridging fundamental physics with technological applications, this research contributes to the broader goal of designing materials for a sustainable and energy-efficient future.
