Printable liquid silicon for local doping of solar cells

• Published in: Solar energy materials and solar cells 2018-06, Vol.179, p.129-135
• Main Authors: Haase, Felix, Lim, Bianca, Merkle, Agnes, Dullweber, Thorsten, Brendel, Rolf, Günther, Christian, Holthausen, Michael H., Mader, Christoph, Wunnicke, Odo, Peibst, Robby
• Format: Article
• Language: English
• Subjects: Back-contact solar cell; Boron; Doping; Electrical resistivity; Emitters; Fabrication; Local doping; Out diffused emitters; Phosphorus; Photovoltaic cells; Printable silicon; Silicon; Solar cells; Studies
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2017.11.003

We demonstrate the application of a liquid-processed doped silicon precursor as a doping source for the fabrication of interdigitated back contact solar cells. We integrate phosphorus- as well as boron-doped liquid silicon in our n-type interdigitated back contact cell process based on laser-structuring. The cell with the phosphorus back surface field from liquid silicon has an efficiency of 20.9% and the cell with the boron emitter from liquid silicon has an efficiency of 21.9%. We measure saturation current densities of 34fAcm−2 on phosphorus-doped layers with a sheet resistance of 108Ω/sq and 18fAcm−2 on boron-doped layers with a sheet resistance of 140Ω/sq using passivated test samples. •Doped liquid silicon (LiSi) printed locally and spin coated on silicon wafer.•140Ω/sq boron emitter from LiSi with 18 fA/cm2 saturation current density.•21.9% efficient back-contact solar cells with LiSi doping source.