In this paper, the application of a bias voltage and a corona discharge system are used to create and store negative charge in silicon nitride films of silicon dioxide/silicon nitride stacks. The silicon nitride films are deposited by low pressure chemical vapor deposition, while the silicon dioxide films are thermally grown. The charge injection mechanism is investigated. Effective lifetime measurements on both textured and planar, as well as both boron diffused and undiffused silicon samples passivated with silicon oxide / silicon nitride stacks show that the creation of negative charge in the nitride layer results in an improvement in the surface passivation for all samples, with very low (<2cm/s) surface recombination velocities demonstrated for planar, undiffused samples. The manipulation of charge can therefore be exploited to improve the conversion efficiency of silicon solar cells.

24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 72-76