Developing computational protocols for molecular spectroscopy that are able to unravel the photophysical properties of photoluminescent inorganic solid state and organometallic materials

Abstract

The aim of the thesis is to conduct a thorough examination of photoluminescent inorganic solid-state and organometallic materials through comprehensive theoretical and computational analyses. This involves unraveling the complexities of their electronic, structural, and optical properties. Motivated by the rich applications and our current state-of-the-art understanding of rare-earth (RE) and transition-metal (TM) materials, this thesis aims to contribute further insights to facilitate and guide the practical design of innovative materials with finely tuned photoluminescent properties. Commencing with the principles of computational chemistry and spectroscopy, and utilizing cutting-edge electronic structure methods including both DFT- and wavefunction-based methods, the study decodes the optical properties of Eu²⁺-doped phosphors and chiral Re(I) complexes. The work encompasses the development of computational protocols, establishing systematic approaches that correlate optical features with structural and electronic characteristics. Furthermore, studies on excited-state dynamics allow for a thorough understanding of the effect of vibronic couplings on the electronic structure and various optical spectra. <br /> At the core of the study, a multifaceted exploration of Eu²⁺--doped phosphors unfolds, introducing a groundbreaking systematic computational protocol adept at predicting electronic structures, optical transitions, and ultimately spectral characteristics of optical bands. The present work demonstrates the powerful synergy between theoretical insights and practical applications, predicting optical properties and enhancing the emission properties of specific phosphors. The research results identify crucial structural, electronic, and magnetic parameters controlling the emissive relaxation and the spectral broadening mechanisms. The research work unravels the interplay between crystal structure effects, spin-orbit coupling, and vibronic coupling in fine-tuning of luminescence. <br /> The study extends into chiral Re(I) complexes, specifically [<em>fac</em>-ReX(CO)₃-L] family, with circularly polarized luminescence, introducing a computational protocol predicting their photophysical and optical properties. The work unveils distinctive emission characteristics influenced by spin-vibronic coupling, expanding the horizons of the computational study into the chiroptical intricacies of photophysics in TM complexes. In summary, the thesis weaves fundamental principles, luminescent systems, and innovative computational protocols into a comprehensive narrative. The implications extend beyond theoretical advancements, promising applications in energy-efficient lighting technologies and luminescent probes. Navigating the intersection of fundamental science and practical innovation, the research presented in this thesis could ultimately illuminate a path toward a future where tailored luminescent materials shape several technological landscapes and industrial progress.