Optimized Laser Doped Back Surface Field for IBC Solar Cells

We present the optimization of the laser doped back surface field (BSF) for interdigitated back contact solar cells (IBC). The POCl3 flow limits the phosphorus concentration in the phosphorus silicate glass (PSG) during furnace diffusion, hence limits the sheet resistance when used as dopant source for laser doping. The saturation current densities of quasi steady state photo conductance (QSSPC) samples correlate with the sheet resistance dependent Auger contribution simulated with EDNA 2. Utilizing the measured saturation current density and contact resistance for various sheet resistances, we optimize the BSF doping for the recently presented 23.24% efficient laser processed IBC solar cell by numerical 3D solar cell simulation.