Univ. Grenoble Alpes, Grenoble, France, CEA, LETI, MINATEC Campus, 17 rue des Martyrs, Grenoble, France, CEA, INES, 50 avenue du Lac Léman, Le-Bourget-du-Lac, France

Production costs and energy efficiency are the main priorities for the photovoltaic (PV) industry (COP21 conclusions). To lower costs and increase efficiency, we are proposing to reduce the number of processing steps involved in the manufacture of N-type Passivated Rear Totally Diffused (PERT) silicon solar cells. Replacing the conventional thermal diffusion doping steps by ion implantation followed by thermal annealing allows reducing the number of steps from 7 to 3 while maintaining similar efficiency. This alternative approach was investigated in the present work. Beamline and plasma immersion ion implantation (BLII and PIII) methods were used to insert n-(phosphorus) and p-type (boron) dopants into the Si substrate. With higher throughput and lower costs, PIII is a better candidate for the photovoltaic industry, compared to BL. However, the optimization of the plasma conditions is demanding and more complex than the beamline approach. Subsequent annealing was performed on selected samples to activate the dopants on both sides of the solar cell. Two annealing methods were investigated: soak and spike thermal annealing. Best performing solar cells, showing a PV efficiency of about 20%, was obtained using spike annealing with adapted ion implantation conditions. © 2017 Elsevier B.V.

Beam Line, Ion implantation, Photovoltaic, Plasma Immersion

Annealing, Costs, Energy efficiency, Ion implantation, Ions, Photovoltaic cells, Plasma applications, Processing, Solar cells, Annealing methods, Beam lines, Implantation conditions, Photovoltaic, Photovoltaic industry, Plasma immersion, Plasma immersion ion implantation, Thermal-annealing, Silicon solar cells