Liquid Phase Epitaxy Doping for High-Performance Emitters in Silicon Solar Cells

Liquid phase epitaxy doping (LPE-D) provides an alternative to the kinetically-governed gas diffusion processes of emitter formation common in the solar industry. It is a lower temperature technique that relies on doping after recrystallization from a liquid eutectic surface layer and results in a more uniform doping concentration profile with the potential for significantly lower saturation currents and improved surface passivation. Being thermodynamically-governed, a wide range of solvent dopant systems can be used to achieve low sheet resistance (<120 fi/sq) emitters. We examine the performance of emitters doped via liquid phase epitaxy using simulation and present experimental demonstration using aluminum boron as the metal solvent- dopant.