Sulfur incorporation into copper indium diselenide single crystals through annealing in hydrogen sulfide

CuInSe2 crystals were sulfurized in a H2S–Ar gas mixture at 575 °C. The focus was on the resulting mass transport, in particular, on the interdiffusion of Se and S. Experiments were done for various sulfurization times, and the resulting S distribution was measured by Auger electron spectroscopy sputter depth profiling and analyzed with the Boltzmann-Matano method. A one-dimensional diffusion process had shaped the S distribution in these crystals. The respective diffusion coefficient was on the order of 10−16cm2∕s, and it varied only slightly with the S content in CuIn(Se,S)2.