Electrochemical synthesis of luminescent ferrous fluorosilicate hexahydrate (FeSiF₆·6H₂O) nano-powders

Being mainly studied as a high-spin iron(II) based compound, ferrous fluorosilicate (FFS) hexahydrate has never been described in the literature as a photoluminescent material. The electrochemical synthesis of strongly luminescent FFS nano-powder from bulk metallurgical FeSi₂/Si substrates is reported in this communication. The main electrochemical/chemical mechanisms involved in the FFS formation are identified. Strong photoluminescence in the red-yellow spectral region of the synthesized nano-powders is supposed to occur via relatively deep Si-related electronic defect states within the FFS band gap.