A novel approach for the evaluation of a phosphorus diffusion design of experiment

The emitter formation in industrial p-type silicon solar cells is generally done by phosphorus diffusion. To optimize the emitter in terms of high efficiency, series resistance and recombination losses of the emitter are balanced out. In this work, we present the results of a design of experiment (DoE) to optimize the main parameters of the P-diffusion. Therefore, we use a novel approach to evaluate the results of the DoE: We approximate the unavoidable correlation between the emitter saturation current density (j0e) and the emitter sheet resistance (ρsh) and create a new target variable (dj0e), which describes the deviation from this correlation. This allows us to understand the key parameters that can minimize emitter saturation current density while keeping emitter sheet resistance at a target value.