Synthesis of pyrite thin films obtained by thermal-sulfurating iron films at different sulfur atmosphere pressure

Pyrite films have been prepared by sulfuration annealing iron films with different sulfur atmosphere pressure at 400 and 500 °C. The optical absorption and electrical characteristics have been determined as a function of the sulfur pressure in the range of 40–100 kPa. For the films sulfurated at 400 °C, with increasing in sulfur pressure, the optical absorption edge increases up to remain a constant value about 0.93 eV while the electrical resistivity shows an insignificant change. By comparison with the films sulfurated at 400 °C with different sulfur pressure, the films sulfurated at 500 °C have high electrical resistivity and low optical absorption edge except for the films sulfurated in 40 kPa sulfur atmosphere. With increasing in sulfur pressure at 500 °C, the carrier density in the films increases and the charge mobility decreases.