Silicon solar cells with interfacial passivation of the highly phosphorus-doped emitter surface by oxygen ion implantation

We investigated oxygen passivation at the interfacial silicon surface on the highly phosphorus-doped region by oxygen ion implantation and showed resulting enhanced electrical properties of silicon solar cells. The oxygen ion implantation converts the dead layer formed due to crystallographic defects in the doping process into an oxygen-induced insulation layer by fragmentation with an optimal amount of energy. The surface dead layer of the highly doped Si emitter was broken by oxygen ions with a fixed-dose and different energies. The optimized implanted oxygen ion energy shows an improved short circuit current after implantation and improved efficiency with enhanced quantum efficiency in the blue region. On the other hand, high energy implanted oxygen ions formed surface defects, resulting in decreased cell efficiency.