Ion implantation of boric molecules for silicon solar cells

authored by: Jan Krügener, Robby Peibst, Eberhard Bugiel, Dominic Tetzlaff, Fabian Kiefer, Marcel Jestremski, Rolf Brendel, H. Jörg Osten
Abstract: We investigate the electrical and structural characteristics after ion implantation of BF_x (x=1,2) for silicon solar cells. Compared to non-amorphizing species, e.g. B, amorphizing species, like BF_x, offer the possibility to lower the thermal budget, which is needed for the curing of implant-induced crystal defects. For implant energies above 30 keV (BF₂) we find a strong degradation of the charge carrier lifetime in the volume as well as an increase of the emitter saturation current density J₀ compared to implantation of elemental boron. This behavior can be related to a defective solid phase epitaxy during the recrystallization in the annealing process after implantation. Implantation of BF₂ at 10 keV and subsequent annealing at 1050 °C for 30 min results in J₀ values of 41±3 fA/cm for a planar, Al₂O₃ passivated 133 Ω/sq emitter. Furthermore, using implantation of BF₂ at 20 keV allows lowering the annealing temperature from 1050 °C, as commonly used for elemental boron, to 950 °C. The latter results in a J₀ of 58±2 fA/cm for a planar, Al₂O₃ passivated 141 Ω/sq emitter.
Organisation(s): Institute of Electronic Materials and Devices
Laboratory of Nano and Quantum Engineering
External Organisation(s): Institute for Solar Energy Research (ISFH)
Type: Article
Journal: Solar Energy Materials and Solar Cells
Volume: 142
Pages: 12-17
No. of pages: 6
ISSN: 0927-0248
Publication date: 29.11.2015
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment, Surfaces, Coatings and Films
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy
Electronic version(s): https://doi.org/10.1016/j.solmat.2015.05.024 (Access: Closed)