Electroluminescence allows rapid characterization of an entire photovoltaic solar cell and visualization of defects at the micrometer scale. Here we focus on the optoelectronic properties of silicon interdigitated back contact cells characterized by electroluminescence. The spatially resolved electroluminescence helps us control the quality of interdigitated back contact structures used in silicon bottom subcells in a three-terminal tandem perovskite on silicon solar cell. Local variations in minority carrier diffusion length, surface recombination velocity and, the impact of resistive and optical losses were analyzed by electroluminescence mapping. In addition, we quantify the radiative saturation current density and the radiative open circuit voltage using the electroluminescence spectrum of the cell. This step allows us to accurately assess the performance limits induced in the device due to the non-radiative recombination.