Indium(I) iodide can be obtained by reacting indium with iodine or indium(III) iodide in vacuum at 300 °C to 400 °C or with mercury(II) iodide at 350 °C.[3]
Indium(I) iodide forms a brown-red diamagnetic solid. Its melt is black. The compound has an orthorhombic crystal structure in the space group Cmcm (space group no. 63) with the lattice parameters a = 475 pm, b = 1276 pm, c = 491 pm.[5]