Formation of n-type pyrite films from electrodeposited iron sulphides: effect of annealing temperature

Abstract The n-type polycrystalline pyrite films were obtained by annealing mackinawite electrodeposited on metallic titanium substrates in sulphur atmosphere in the temperature range 523–773 K. The detailed structural and morphological characterisation of the films shows that an increase of crystallite size and a porosity decrease was achieved by increasing the sulphuration temperature. The measurement of thermoelectric effect indicates that pyrite films present n-type conduction, which is attributed to the diffusion of Ti atoms from the substrate. The Seebeck coefficient varies from −54 to −24 μV/K, depending on pyrite grain size.