Defect luminescence at grain boundaries in multicrystalline silicon

Multicrystalline silicon is characterised by extended defects like dislocations and grain boundaries. Grain boundaries in this material can show radiative recombination in the near infrared (NIR) region even at room temperature (Dreckschmidt et al., Proc. 23rd European Photovoltaic Solar Energy Conference, Valencia, Spain, 2008, p. 407. [1]). Here we present results of further investigations by the electroluminescence method regarding these phenomena. It turned out that carrier recombination at these centres is negligible. From temperature dependent measurements activation energies of the different centres were determined. Defect schemes for the grain boundary luminescence are proposed (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)