Improving PERC cells requires rather different strategies than standard cells have required, demanding concrete improvements in materials, manufacturing procedures and fabrication tools. Highlights of this paper include:
- In recent years, PERC cell efficiencies have increased by about 0.4%abs per year in mass production. This paper discusses how the industry’s median efficiency can be increased to 24% within about seven years while fabrication cost may drop to about half.
- A simulated roadmap shows that, presently, efficiency is either limited by a homogeneous emitter, or in case of a selective emitter by wafer lifetime. The next improvements are cleaner fabrication, Ga doping of wafers to reach 2 ms lifetime, better emitter profiles and emitter passivation, finer metallization, and improved hydrogenation.
- 24% efficiency will not be reached by solely optimising existing technology, but by steadily improving existing technologies further, which requires continuous R&D efforts and the further development of some specific manufacturing tools.
First published in Photovoltaics International - Volume 41