A temperature dependence of intensity for band to band (BB) luminescence of a solar cell excited by constant current in forward biasing was investigated. The obtained temperature dependence is untypical for silicon, i.e. the intensity of the BB luminescence increases with temperature. We analyse our results in view of thermally induced change of excess carrier concentration. Two temperature dependent nonradiative recombination processes limit the carrier concentration. One is the recombination in the bulk, mediated by deep impurity levels and the other is the surface recombination. The surface recombination limits the minority carrier diffusion length to the thickness of the solar cell. We show that the interference of both recombination processes causes the effective lifetime to increase upon increasing temperature. Thereby the deep level mediated recombination dominates at high temperature, whilst the surface recombination is dominant at low temperatures. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)