Prof Sayan Bhattacharyya, Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata
Metal-halide perovskites with a soft ionic lattice have emerged as revolutionary optoelectronic materials in recent years. While lead-based systems have made tremendous progress in photovoltaics, the lead-free counterparts are promising game-changers in optoelectronic devices and photocatalytic reactions. Moving ahead from the state-of-the-art three-dimensional hybrid perovskites, the two-dimensional (2D) analogues have captivated the interest of the researchers because of their better moisture stability and reduced ion migration through the interlayer hydrophobic organic spacer molecules in between the inorganic octahedral layers. The dimensional changes can occur either in the lattice or due to the morphological growth of the nanostructures. This lecture will start with the CsPb(Br/I)3 nanosheets, followed by the Ruddlesden-Popper (RP) and Dion-Jacobson (DJ) systems, and the influence of structure on their optoelectronic properties. Thereafter, the metal-substitution induced 3D to 2D structural transformation of a lead halide perovskite, and the incessant light/dark reversible assembly of non-lead perovskite nanoplatelets will be discussed.