Rethinking tolerance factor analysis for chalcogenide perovskites.

Tolerance factor analysis has been widely used to predict suitable compositions for oxide and halide perovskites. However, in the case of the emerging chalcogenide perovskites, the predictions from the tolerance factor have failed to align with experimental observations. In this work, we reconsider how tolerance factor is being applied, specifically adjusting for the effect of increased covalency of bonding on the ionic radii. Further, we propose a series of screening steps based on the octahedral factor, tolerance factor, and electronegativity difference to better predict the formation of sulfide perovskites.

Synthesis of BaZrS3 and BaHfS3 Chalcogenide Perovskite Films Using Single-Phase Molecular Precursors at Moderate Temperatures.

Chalcogenide perovskites have garnered interest for applications in semiconductor devices due to their excellent predicted optoelectronic properties and stability. However, high synthesis temperatures have historically made these materials incompatible with the creation of photovoltaic devices. Here, we demonstrate the solution processed synthesis of luminescent BaZrS3 and BaHfS3 chalcogenide perovskite films using single-phase molecular precursors at sulfurization temperatures of 575 °C and sulfurization times as short as one hour. These molecular precursor inks were synthesized using known carbon disulfide insertion chemistry to create Group 4 metal dithiocarbamates, and this chemistry was extended to create species, such as barium dithiocarboxylates, that have never been reported before. These findings, with added future research, have the potential to yield fully solution processed thin films of chalcogenide perovskites for various optoelectronic applications.