In this work we study the modulated photocurrent arising from experiments performed in the recombination regime on amorphous and microcrystalline semiconductor samples. The influence of the illumination intensity on the results obtained from the recombination-regime modulated photocurrent (RRMPC) technique is studied both from measurements and computer simulations. A wide range of density of states (DOS) distributions is used to simulate different material qualities. Applying a computer code that takes into account all thermal and optical transitions involving gap states, modulated photoconductivity experimental data are simulated. The DOS is then reconstructed from the simulated data following the RRMPC method. Simulations performed under different light intensities lead to the empiric definition of an indicator parameter, which allows us to evaluate the validity of the hypotheses of the RRMPC method for a particular experiment. Measurements for microcrystalline and amorphous hydrogenated silicon samples are presented as examples. (C) 2003 Elsevier B.V. All rights reserved.