Progress on Numerical Reactive Diffusion Modeling of CuInSe2 Phase Formation for Solar Cell Applications

Numerical modeling of chalcopyrite (CuInSe2) absorber layer formation by rapid thermal annealed stacked elemental layers provides a valuable tool to address the microscopic phase formation process, which significantly determines the absorber layer properties in solar cell applications. We present a one dimensional kinetic modeling tool describing the diffusive reaction kinetics for layers of partial miscible systems. The diffusion is described temperature dependent and by calculating the latent heat the results were compared with differential scanning calorimetry measurement curves. Applying the numerical simulation to elemental layers of Cu, In and Se, first binary compounds are observed. With the presented progress in the model the absorber can completely react to CuInSe2, after sufficient intermixing of the elements. The results show a good agreement with experimental data with regard to the temperature range of the reactions taking place.