Belgian lab IMEC is claiming over 20% efficiency from silicon solar cells designed for mass-production.
The 125x125mm p-type silicon cells are 'passivated emitter and rear cell' (PERC) construction, with a simple homogeneous emitter, screen-printed silver front contacts (65μm fingers), two busbars, and an adapted aluminium back-side metallisation.
"This processing simplicity holds the potential for cost reduction and efficiency increase in an industrial production environment," said IMEC. At the moment the transfer of this process to 156x156mm wafers is ongoing."
The cells were processed at IMEC's newly completed solar cell pre-pilot line which has been built around E10m of equipment and can process several thousand 156x156mm wafers per week.
"A simple PERC cell is IMEC's answer to short term aspiration of the photovoltaic industry to reduce the cost per Watt peak of silicon solar cells," said IMEC director of photovoltaics Dr Jef Poortmans. "We are delighted to have achieved an efficiency of more than 20% for a standard PERC cell, featuring a large-area, only a homogeneous emitter, and screen-printed silver contacts."
Presented at Intersolar in San Francisco, 20.04% efficiency has been certified by Fraunhofer ISE-Callab.
