In-situ phase formation study of copper indium diselenide absorber layers from CuIn nanoparticles and evaporated selenium

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 °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 °C to 540 °C. - Highlights: ► Synthesis and characterisation of CuIn nanoparticles ► Preparation of precursor layers for CuInSe2 from nanoparticles ► Characterisation by dynamic scanning calorimetry and in-situ X-ray diffraction ► CuInSe₂ formation from 300 °C although high amount of sodium included