Abstract
This paper reports on the results of several yeats of investigations aiming at simplification and efficiency improvement of a low cost scr een printing solar cell process. All solar cell process operations, materials and equipment have been, with this respect, critically examined, re-optimised and, if necessary, removed or replaced. A simple industrial type process for high efficiency multicrystalline and monocrystalline solar cells has been developed. The process sequence is based on screen printed contacts fired through a PECVD SiNx antireflection coating layer: The total number of processing steps has been reduced to six. All processing steps can be easily transferred into big volume production lines. Solar cells with average cell efficiency above 15% and 17% were respectively obtained on large al-ea multicrystalline and monocrystalline substrates. Including in the processing sequence the advanced processes of isotropic texturisation and selective emitter increases the cell efficiency to 16.9% and 17.9% respectively for multi- and monocrystalline silicon. A new cell concept, metallisation wrap through cell (MWT), has been recently introduced. The cell efficiency of 13.1% has been obtained in a simple cell processing sequence based on scr een printed contacts.