Ferro Electronic Materials, a supplier of materials for fabricating photovoltaic silicon solar cells, has developed a new series of silver and silver/aluminum contact pastes. The PS 33-650 series provides contacts for new high-efficiency silicon cell designs such as n-type, bi-facial and interdigitated back-contact solar cells.
Ferro's PS 33-650 series conductor pastes enhance electrical efficiency through their low contact resistance, optimum bulk resistance, and excellent line resolution and aspect ratio, according to the company. These materials are suitable for various cell designs based on n-type or p-type wafers, and have excellent solderability and adhesion when used with leaded or lead-free solders.
The cadmium- and phthalate-free pastes are RoHS-compliant and are compatible with lead-free aluminum inks used for emitter formation in some n-type silicon configurations, the company adds.
‘It is challenging to produce low contact resistance to the passivated p-surface while maintaining low leakage current across the junction,’ says Aziz Shaikh, Ferro's director of photovoltaic research and development. ‘These new p-surface contact materials provide low contact resistance to passivated boron-doped emitters while maintaining good diode quality, resulting in up to 20 percent efficiency from n-type mono-wafers in laboratory tests.’
SOURCE: Ferro Electronic Materials