Solution Preparation of Optical and Electronic Metal Halides

Perovskites and perovskite-inspired halides are continuing to attract the interest of a broad community of researchers as prospective materials for optoelectronic applications. In addition to their outstanding optical and electronic properties, the solution-processability of metal halides is among their greatest advantages. Low-temperature solution preparation not only reduces the processing cost but is also partly responsible for the remarkable diversity in chemical compositions and crystal structures of this class of materials. However, the solution chemistries of most metal halide systems and their relationship with the observed structural and chemical diversity are poorly understood. This is exemplified by the great variety of solution processing conditions reported for both new materials synthesis and solution deposition of thin films reported in the literature. In this talk, our ongoing research efforts to study and develop understanding of several metal halide systems will be summarized. Our combined computational and experimental approach includes UV-vis spectroscopy and electrospray ionization mass spectrometry (ESI-MS) measurements, small-angle X-ray scattering (SAXS) and density functional theory (DFT) calculations. Our early success in several pseudoternary systems will be described along with the outstanding challenges in studying more complex multicomponent systems will be discussed. This study shows that understanding the solution chemistry of multinary metal halide systems could be a valuable tool for discovering new functional materials for practical applications.