OFOCell concept for low cost silicon photovoltaics

The incredible growth rates of the PV solar industry have allowed manufacturing efficiencies that are unheard of in other industries. Nowadays in the solar cells industry the main effort is directed to the cost reduction of the solar panels fabrication which will decrease the average price per kWh from presence 0.20 €/kWh down to 0.07 €/kWh in 2020. Generally it is realized by using much cheaper polycrystalline wafers, reduction of the overall wafer thickness and/or simplification of the production complexity. We propose the simplification of the production process of silicon solar cells using only one step millisecond annealing for the whole solar cell processing and replacing standard phosphorous thermal diffusion by plasma immersion ion implantation. Our technology can be directly transferred to an in-line production process leading to significant cost reduction and decreasing the amount of chemicals used during solar cell manufacturing. Due to one step millisecond range flash lamp annealing (FLA) the overall thermal budget needed for the solar cell fabrication is significantly reduced. Moreover the emitter formed by ion implantation and FLA is clean and allows the precise control of the dopant concentration and width of the p-n junction.