Optimization of Boron Diffusion for Screen Printed n-PERT Solar Cells

In this study we designed and fabricated n-PERT solar cells and we investigated the effect of different boron emitter profile (emitter surface concentration and emitter junction depth) on the cell performance. The emitter depth was varying in the range 0.4μm and 0.75 μm and the resulting RSh between 74Ω/sq and 140Ω/sq. From QSSPC measurements we observed that a better passivation is achieved in case of low RSh. almost independently on the emitter depth. However, to achieve the best efficiency at cell level it is necessary to use deeper doping profiles, since for shallow doping profiles the metal recombination losses increase considerably.