Time-resolved photoluminescence studies were performed on epitaxially grown InP either doped with iron or with iron and sulphur to gain information on the carrier trapping characteristics of Fe3+/Fe2+. The carrier trapping time was found to be dependent on both the iron and sulphur concentrations, from which the electron and hole capture cross sections of the Fe deep centers are determined as σe=1×10−15 cm2 and σh=6×10−15 cm2, respectively.