The creation and annealing kinetics of light induced metastable defects were studied in a set of good quality a-Si1-xCx:H alloys (x less than or equal to 0.11) using the constant photocurrent method (CPM) at room temperature. Light induced metastable defects created at room temperature started annealing at higher temperatures, when the alloys had high carbon content. The annealing activation energy distribution functions of the hydrogenated amorphous silicon-carbon alloys were calculated using the method proposed by Hata and Wagner (J. App. Phys. 72 (1992) 2857). The annealing activation energy distribution function is a narrow Gaussian peaked at about 1 eV for the unalloyed sample. For the alloys, the peak position shifts to higher energies and the half-width of the distribution decreases with increasing carbon content. The results obtained are discussed within the framework of the "weak-bond breaking" (Phys. Rev. B 32 (1985) 23), and the "hydrogen-collision" (Phys. Rev. 59(8) (1999) 5498) models. (C) 2002 Elsevier Science B.V. All rights reserved.