Hot-melt screen-printing of front contacts on crystalline silicon solar cells

This work describes a study of hot-melt (HM) screen-printing of front contacts as a function of print speed, print table temperature, squeegee temperature, paste composition and firing profiles. The results presented here will show that it is possible to print lines with higher aspect ratio compared with standard screen-printing. Optimum parameters for printing seems to be high print speed in combination high squeegee temperature. There is a trade off between the height and width of the finger lines when adjusting the table temperature. Firing with fingers facing down at high belt speeds results in shrinking of line width between 15% and 20%. At present, the best efficiency results from HM screen-printing are at par with standard printed solar cells.