Development of industrial processes for the fabrication of high efficiency n-type PERT cells

Thomas Blévin (1, 2) , Adeline Lanterne (1, 3) , Bernadette Grange (3, 1) , Raphaël Cabal (1, 3) , Jean-Pierre Vilcot (2) , Yannick Veschetti (1, 3)

1 LITEN - Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 INES - Institut National de L'Energie Solaire

In this work, two process simplifications for n-type PERT (passivated emitter rear totally diffused) bifacial solar cells are investigated. Both are based on a single thermal treatment for elaborating boron and phosphorus doped regions aiming at reducing the number of high temperature steps of standard process. The first simplification shows a mixed co-diffusion from a gaseous source of phosphorus and a boron doped dielectric layer elaborated by low frequency plasma enhanced chemical vapor deposition (PECVD). The second exhibits two independent ion implantations, followed by a co-anneal/activation step. In both cases, implied open-circuit voltages are similar to standard process ($\sim$660-670 mV) and emitters allow good contacting by screen-printing ($ρc$= 3.0-5.0 m$\Omega$ cm$^2$). PERT cells resulting from these processes show very promising performances with efficiency up to 19.7% on industrial 156 x 156 mm$^2$ pseudo square Cz wafers.

Keywords: Bifacial; PERT; Silicon solar cells; Co-diffusion; Ion implantation; Co-annealing

Domains: Engineering Sciences [physics]; Electric power; Optics / Photonic; Materials; Micro and nanotechnologies/Microelectronics

Thomas Blévin, Adeline Lanterne, Bernadette Grange, Raphaël Cabal, Jean-Pierre Vilcot, et al.. Development of industrial processes for the fabrication of high efficiency n-type PERT cells. Solar Energy Materials and Solar Cells, 2014, 131, pp.24-29. ⟨10.1016/j.solmat.2014.06.022⟩. ⟨cea-02570711⟩