Using hotmelt-inkjet as a structuring method for higher efficiency industrial silicon solar cells

A procedure was developed to form openings in dielectric layers for subsequent contact formation based on inkjetting hydrocarbon wax. Basic investigations on the process focussing on obtaining the minimal feature size are presented. Continuous fine line openings below 20 m width in the mask were obtained, which allowed for wet chemical etching of the underlying anti-reflective coatings. Subsequently nickel and Silver plating were used to form ohmic contacts, leading to a width of the metallization of down to about 30 mu;m. The results were achieved on micro-structured silicon surfaces covered by a silicon nitride layer commonly used in the photovoltaic industry.