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2010
Conference Paper
Titel
Very low emitter saturation current densities on ion implanted boron emitters
Abstract
Ion implantation is the technique of choice for introducing dopant species into semiconductors in CMOS devices. In photovoltaics ion implantation could be an interesting alternative to tube furnace diffusion processes. However, one issue of major importance concerning ion implantation always is the removal of the damage introduced by the implantation process as solar cells always require a defect free, perfectly passivated surface. Thus the surface quality and passivation of boron and phosphorus implanted samples was investigated within this work. It has been found that after an appropriate annealing the introduced damage of both boron and phosphorus implanted surfaces can be completely removed. Very low saturation current densities of <25 fA/cm2 could be achieved for both boron and phosphorus implanted surfaces after passivation with Al2O3 and SiO2 respectively. On n-type back junction solar cells were both the phosphorus FSF as well as the boron emitter have been realized by ion implantation conversion efficiencies up to 19.4% could be achieved.