Novel low temperature front side metallisation scheme using selective laser ablation of anti reflection coatings and electroless nickel plating

For the development of a new low temperature front side metallisation the selective opening of the front surface anti reflection coating is inevitable. Secondly the selective deposition of an electroplating seed layer is necessary. In this paper the approach of using a laser ablation process to selectively remove this layer is presented. The possibility to perform this step without inducing damage into the solar cell front surface is demonstrated by optical methods like scanning electron microscopy as well as lifetime measurements. Dark and light IV measurements on solar cells show the potential of the process when using photo lithographically defined titanium / palladium / silver front side metallisation by reaching an efficiency of 16.5% with a planar front surface. The possibility to circumvent this laboratory process by using electroless nickel plating is demonstrated as well.