Laser micro-sintering as a new metallization technique for silicon solar cells

A laser-enhanced process to manufacture front side electrical contacts of silicon solar cells has been developed. A metallic powder is spread on top of a silicon wafer. The energy supplied by a laser beam sinters the powder according to a defined pattern, allowing the formation of thin electrical contacts to the silicon wafer. The rest of powder is removed and can be reused. To increase the conductivity of the contacts a light induced silver electroplating step has been performed. Different contacting metals have been tested (silver, molybdenum and tungsten). The first cells achieved fficiencies about 14.5% and a fill factor of 73.5%. Analysis of the cells was made by light microscopy, SEM and AFM. Characterization has been done by I-V and Suns-Voc measurements.