Investigation and optimization of Cd-free buffer layers In2S3 and Zn(O, S) for Cu2ZnSn(S, Se)4-based solar cells

We present three different working modes of scanning near-field optical microscopy which provide complementary information about the electro-optical properties of solar cells. Those working modes allows to study the local light scattering and trapping in textured solar cells, the local light propagation inside the cell and the impact of lateral inhomogeneity on a nanoscopic scale. Due to the presence of evanescent light modes, the presented techniques give access to important physical effects which is only possible in the optical near-field.