In this work CuInSe2 (CISe) thin films were fabricated by rapid thermal processing of printed CuIn nanoparticles and thermally evaporated selenium as precursor layer. Research is focused on real-time investigations such as in-situ X-ray diffraction and dynamic scanning calorimetry. These measurements show CISe formation starting at 300 degrees C. Significant amount of intermediate phases as reported for state-of-the-art rapid thermal processing of stacked elemental layer was not observed. The morphology of the nanoparticulate layers was examined by field emission scanning electron microscopy. Grain size developed from nanosized binary CuIn nanoparticles to microsized CISe grains. Porosity decreases in the temperature range from 340 degrees C to 540 degrees C. (C) 2012 Elsevier B.V. All rights reserved.