Iron sulfide ink for the growth of pyrite crystals.

Iron pyrite (FeS2, Fool's Gold) is a non-toxic, earth abundant semiconductor that exhibits promise for use in energy conversion and storage devices, such as the cathode material for batteries, thermoelectrics and optoelectronics. However, pyrite's potential as an energy-critical material is being curbed due to problems with controlling composition, stoichiometry and bulk and surface defects. To overcome these problems, simple and scalable methods to grow high quality crystalline pyrite for in-depth studies are necessary. In this study, we report a facile approach to create high quality, micron sized pyrite crystals from the FeS wire molecular ink. Growth of high quality pyrite crystals is examined and a model for growth and surface facet dependent activation energy is proposed. Unique thermal measurements are preformed that allow for insight into the pyrite's crystallinity and thermoconductive properties. It is shown that as made pyrite crystals exhibit high crystallinity which will be vital for future in-depth studies and device fabrication.