PeroSeminar | 07 August 2025

The work is devoted to a comprehensive study of the optical and photoelectronic properties of single crystals of hybrid (MAPbI₃, MAPbBr₃) and inorganic (CsPbBr₃) perovskites using high-resolution spectroscopy in a wide range of frequencies (15–20,000 cm⁻¹) and temperatures (3–330 K) and contactless photoconductivity. New low-frequency phonon modes were discovered for the first time and their parameters were determined. Hysteresis of the temperature dependences of the spectra in the region of phase transitions was established, confirming their first order. Splitting of spectral lines at ~70 K was detected, associated with the transition from free rotation of the organic cation to its tunnel dynamics. The absorption coefficient of single-crystal MAPbI₃ samples near the fundamental absorption edge was estimated. In CsPbBr₃, the activation energies of exciton decay and the exciton binding energy were determined. The results obtained are important for the development of stable and efficient optoelectronic devices, including solar cells and radiation detectors. Results of the work are published in 6 articles in peer-reviewed journals (WoS, Scopus) and 1 patent.