Low temperature formation of CuIn1 − xGaxSe2 solar cell absorbers by all printed multiple species nanoparticulate Se + Cu-In + Cu-Ga precursors

In this work an all nanoparticulate precursor for application in Cu(In1 − xGax)Se2 solar cell absorbers is presented. Binary Cu-In nanoparticles, Cu-Ga powder and elemental Se nanoparticles were mixed in dispersion and deposited on Mo-coated substrates. Research was focused on Cu(In1 − xGax)Se2 layer formation kinetics, phase composition characterised by differential scanning calorimetry and in-situ X-ray diffraction (XRD). Furthermore phase composition and morphology were studied by ex-situ XRD, Raman spectroscopy and scanning electron microscopy. The results revealed a fast consumption of the precursor and the formation of CuInSe2 below 340 °C. Binary secondary phases were not observed at any temperature.